Pool Heating

Pool heating provides more enjoyment and comfort to swimmers. But since pool heating can add up to high heating bills and consumes a lot of energy, pool owners should use energy-saving pool heating systems such as solar pool heaters.

1,876 Questions
Swimming Pools
Pool Care and Cleaning
Pool Heating

Why would pool water be cloudy?

  • Cloudy water can be caused for a number of reasons: poor filtration, imbalance of chemicals in your pool such as total alkalinity, pH, calcuim hardness and chlorine, imbalance of total chlorine and free chlorine (referred to as chlorine demand), etc.
  • It could also be that your have a lot of micro particles that your filter cant catch. You might want to try a chlorifier that makes the tiny particles clump together and easy to remove with a vacuum.
  • This condition occurred with me twice last year. The diagnosis for me was "mold". I was using Bacquacil, and the dealer told me to test for mold by pouring 1 gallon of bacquashock directly into the skimmer. If the return subsequently starts blowing white instead of clear water, it's mold. The only recourse was to superclorinate, which of course made a big mess, then vacuum and restart with bacquacil again after pool cleared up.
  • The water is cloudy due to poor water chemistry. Most likely a pH problem. Take water into a pool store. Sometimes cloudiness is also due to using a calcium based shock. Such as the brand sock-it
  • Double shock your pool with liquid chlorine (12.5%). A double shock is 2L of chlorine for every 10000L of water in your pool. The cloudiness is likely the start of algae. You may also find a clarifier helpful after double shocking to help eliminate the particles that will settle to the bottom of the pool.
  • Make sure all of your levels are balanced. then if there is no improvement add a clarifier ONLY if you are using a sand or cartridge filter. it will clog a filter.
  • First make sure ALL your levels are good depending on the filter type that is used perform a backwash vacuum. if using a sand filter try some DE in small doses for it will clog the filter let it run through the filters watch your pressures when they get to the point you normally backwash than do so.
  • Have a complete water analysis to find the cause for cloudy water.
  • I disagree with all the above answers: There are only two main causes for a white cloudy pool #1 is lack of Sanitizer. #2 is lack of filtration due to a poor filter or a clogged pump. I would start with #2 turn your system off make sure there are no blockages in your pump basket,skimmer & main drain.Make sure your filter is properly cleaned.Then #1 check your sanitizer level make sure it is in a safe operating range. Your pool water should be turned over every 6-8 hours.
  • Cloudy pool water is usually the result of one or more of the following: filter/ filtration problems, high calcium hardness level, high conditioner level, high pH, low pH, high total alkalinity, high level of total dissolved solids, low chlorine level, algae, large volume of microscopic particles in the pool water.
Swimming Pools
Pool Building and Repair
Pool Heating

What is the cheapest way to get an inground pool?

purchase one from a reputable supplier

Swimming Pools
Pool Care and Cleaning
Pool Heating

How do you determine the correct gas pool heater size for an above ground pool?

This a bit involved, so work through this with me ...

The easiest way is to contact InyoPools online or call them 877-372-6038

The goal is to have a heater that has enough capacity to heat the pool to your desired level in a reasonable amount of time. Maintaining that temperature is a lot easier once the pool is up to temp.

First, the capacity of most pool heaters are rated in BTU's or British Thermal Units. One BTU is the amount of heat required to raise the temperature of one pound of water, one degree F. And since there are 8.33 pounds per US gallon it takes 8.33 BTU's to raise one gallon of water, one degree F.

Now let's calculate:

1. Determine the number of gallons in your pool (G).

2. Determine the amount in temperature that you want to raise the pool temp (the easiest way to figure this is to use the air temp as the minimum and the desired pool temp as the maximum) (Delta T).

3. Calculate the number of BTU's needed (BTU) per gallon of water by multiplying step 2 x 8.33. Multiply this number times the gallons of water in your pool (G). This is the number of BTU's to raise your pool temp from the minimum to desired temp.

4. Determine how FAST you want to be able to go from the minimum temp to the desired temp (in hours) (H).

5. Divide the total number of BTU's from step 3 by the hours in step 4 to yield the BTU'S per hour that your heater will need to deliver.

6. Multiply Step 5 by a error factor of 20% and add to step 5. This is approximately the size of heater that you will need.


1. Assume pool volume, G = 10,000 gallons 2. Assume 80F desired pool temp and 60F air temp. Delta T = 80 - 60 = 20F 3. BTU's per gallon x Delta T: 8.33 x 20 = 166.6 BTU's per gallon. BTU/Gal x Gallons (G): 166.6 x 10,000 gal = 1,666,000 Total BTU's. (Wow, seems like a lot!) 4. Assume I want to be able to warm the pool in two days of continuous operation = 48 hours. 5. Total BTUs / Hours: 1,666,000 / 48 = 34,708 BTU's per hour. 6. (BTU/Hr x 20%) + BTU/Hr: 34,708 x 0.20 = 6,941 BTU's 6,941 + 34,708 = 41,649 BTU's per hour.

Now, most pool heaters come in a round number of BTU's like 50,000, 100,000, 150,000, etc. You should select the closest size to your needs (usually on the higher side is best).

Hence, for this example, a 50,000 BTU heater would be more than adequate.

Obviously, you could also work these calculations backward to determine what Delta T you could handle given a certain size heater and pool size.

... SUGGEST YOU NOT SIZE A HEATER BASED ON THE ABOVE ARTICLE !!! So sorry, I find so many exceptions (wrong statements and conclusions)... This novice article/ suggestion is a nice try but misses the mark and should not be used to size a pool heater.

Firstly there are different design conditions for pool water temps, and different methods, which must be used depending on whether the heater is a gas (i.e. natural, naphtha, propane) or an electric resistance or heatpump.

Most people are likely to use natural gas due to the low cost of this fuel. Heat pumps can be about the same operational costs or cheaper, depending on your gas and electric rates in your area. In my area a heatpump is at a par with the cost to operate a natural gas heater. (Considering a 4.0 C.O.P.)

Calculating a pool heat loss is involved for sure and one must calculate evaporation, radiant losses and convection losses (calculation performed within the evapo-transpiration rate). Conduction can be said to be about 3% as a standard so this calculation is not needed to be input as a variable, but should be added to the calc at some point for the conclusion. All these calculations are done against a varying outdoor ambient (temperature, humidity, wind) condition.

Without a pool cover the losses can be up to 3 times that of using a pool cover (Lower wind across the pool surface is a lower rate of loss). Normally it's a factor of about 2-2.5. In the case of a body of water, the convection (wind) is the "driving force� behind the evaporation portion of the formula's calculation. So one should also pre-determine whether a pool cover is to be used before calculating. (Typically a pool without a cover will require twice the btuh for pool water maintenance (twice the heater sizing) and will naturally take longer hours for initial heating.

Anyone not using a pool cover and heating a pool is ludicrous and will pay for it. Note that with a pool cover, the cover remains on the pool 24 hours a day except for the time the pool is used which can be about 3 hours for most residential pools. Evaporation accounts for about 70% of the pool heat losses so pool covers do a great job as water vapor is trapped below the cover and thus so is the heat (a saran wrapping of 1 mil would do the same as a vapor barrier).

For a gas heater sizing you can design with it in mind to let the pool water temperature drop and turn on the pool heater at whatever day you want to use the pool. This sizing will then be based on the number of hours you want to wait for the pool to heat up. It will also be based on the starting water temp and final swim temperature you want. There will be the water volume to heat plus the ambient losses during the hours of heating, plant room, exposed piping losses, etc. (which can be about 8%) occurring during the heat up time. (This method, I think, is what the above article was trying to get to, but sorely missed de-rating the heater (you have to figure it's 3-5 year efficiency not it's new efficiency), forgot about the on-going heat losses to the ambient and failed to mention adding piping/plant room losses, activity losses, with or without a pool cover usage.

The article above is very miss leading as it does not correctly conclude the proper gas heater size... Heating efficiency; I know some mfgrs. Say they have 99% efficiency, but this is not a practical truth when measured in the field. Plus there is the exchanger losses which build up (water heated over 40 deg C will precipitate iron, magnesium, calcium, etc.) so fouling of the exchanger (loss of BTUH output) does occur at faster rates than with heatpump s. I suggest you always use a 75% output gas btuh against any gas heater mfgr's claim.

For heatpump s it's very different. These are sized to the maintenance of the pool temperature for the estimated hours the pool is covered and estimated hours the pool is uncovered. Swimming activity also is an important equation to add, as this activity accelerates the pool heat loss (accelerates evaporation, plus water losses from swimmers) while un-covered. If anyone tried to size a heatpump on the volume guestimate above you'd end up with a huge heatpump and the initial cost would be prohibited. (You�d never buy a heatpump based on this guestimate using the miss-leading volume method, where-as in some parts of the USA and other world countries; the heatpump is the only way to go). Heat pumps require the correct detailed calculation for the heat loss of a body of water that utilizes the items mentioned above in this article with evaporation calculated from the convection and other factors in a formula that calculates the water pressure difference to that of the air with a database of 24-hour historic ambient low averages.

Having said it's very different for Heat pump sizing methods and calculations, it doesn't have to be... I happened to size my gas heater using the heatpump sizing formula; i.e. the only correct calculation for determining pool heat losses; surface heat loss based formula, and sized my heater with the input data that: the pool stays covered 24 hrs a day except 3 hours a day for swimming. I ended up with a very small 100,000 btuh heater that does the job great.

Now having said this let me also include that heat pumps are also set up differently than gas heaters typically, unless you use the accurate heat loss method described here-in to which I refer and not show..sorry. Heat pumps are set up to be able to run as many hours a day as they need, and to only turn on once a day. (so heat pumps are always simply maintaining the pool temp at a constant, (generally) and these amounts of heat are relatively small. I used this same set-up for my gas heater, so it simply maintains the pool temperature I have set. (always ready for me to jump in whether it's day or 3 am!) You don't need to have the pool heated at 3 am, as the mass of water has a great retention with a cover, so you do allow it to reach your set temp and then wait for the following day; during sunshine (higher ambient temps for higher effeciency) to bring back the set temperature.

To help think about heat loss from a body of water (swimming pool) consider a well, lots of water; say 10,000 gallons and you heat it, and it stays heated for long periods of time as the surface is say only 2 meters across. Now take the same water volume; say 10,000 gallons, spread it 1/2" thick across a field and wait one day: it's all evaporated and gone! The heat loss for the well was minimal, the heat loss for the field of water; tremendous. So surface water calculation is the only true calculation to use for a pool, with a check on the warm up time (if you plan to let the pool water drop a day or so, then raise it, then drop it, etc.) Pools with big volumes and small surface areas lose less heat/ hr and require smaller heaters to maintain the maintenance temperatures.

Take a hot cup of coffee... let it stand in a wind protected place...takes a long time to cool down. Now take the same cup of coffee and start blowing ambient air on it;(like a pool with wind at it's surface) now lots of heat loss, and the temperature can cool up to 2.5-3 times faster..(The wind (convection) accelerated the evapo-transpiration! Add a swizzle stick in the coffee (swimmers in a pool) and you further accelerate the rate of radiant and evaporation losses.

This is why using a "volume based heat requirement formula" as described above is not correct, even if you do add these minor corrections mentioned here-in. The lack of pool cover mention is the articles biggest err...

I'm sorry to not go on with providing the correct calculation formula and many other details, but thought one reading this article should be made aware, this one is not to follow...

Note; most economically sized heating plants will require about 3-3-1/2 days to provide initial warm up (considering about 82-85 Deg F) and be proper for the best operating costs. For myself, I can't see swimming in pool water less than 86 deg F and we keep about 89 Deg F. most of the time!(old folks)

pool man

Interestingly enough, poolman, for rough estimates, the formula at the top of the article is accurate enough. Since I can't buy a 103356.741 BTU heater, the above formula gives me enough information to make an informed decsion on what size heater to buy. Given the length of your response, and the fact that you don't provide your actual formula, I am left to assume you sell pool heaters. Do you service the WNY area???

A thought added by robtig1:

I think that both of these answers have equal merit. Essentially, the raw volume btu calculation needs to be done not based on the delta T (change in desired temperature), except when determining the time taken to initially heat the pool, but rather, the raw volume btu calc needs to be applied to the heat loss principles as mentioned by poolman's response.

In short, I think it is the rate of heat loss that needs to be determined and then take that delta T and multiply etc.. by the 8.33 and volume etc etc... A simple average day experiment will let you know the change in temp you wish to achieve. Just heat your pool up, and see how much it cools down during a 24 or 48 hour period. This will give you a simple version of pool man's very complicated assessment of heat loss through evaporation, line loss, etc..

My purpose of these calculations is to assess the size of a solar heater needed to warm up my pool. I did a simple spreadsheet, and even with a good 12 hours of sunlight optimistic I fear that my input at such a low BTU rating will hardly dent the temperature of my pool. I am calculating on 6,600 btu per hour output on a vacuum tube assembly with 60 tubes. Initially I thought that number to be high, but on my 140,000 litre pool it only warms it up 0.18 degrees F per day. I feel i must be doing something wrong as I should not need an acre of solar panels to heat my pool. I would be happy if I could even add 1 degree per day to my pool. If anyone has any advise on this, I would be happy to hear it!!


The calculations used in the 1st part are the same calculations and numbers used in Ordini's Pools web page. Ordini's continues on their page to give information on surface area and losses, as well as cost comparisons between various available heater styles.


Solar heaters will NOT heat your pool to a swim temp. They are a secondary heat source only. You need 400,000 or more btu heater.

Paul: I have an in ground 12 by 24 foot pool with a 30kw gas heater. It raises the temp about 1 deg C in two hours. BUT in all but high summer [in south u.k] thr ground losses through the pool walls can drop the temperature 2 degress C overnight even with a pool cover and home made 1 inch thick foam slabs laid on yop og the cover.

So.. if your builder didn't put insulation round the pool sides / floor, which mine hasn't got, then [as i do] you either pay the gas bill consequences or only use the pool when the ground temperature has hotted up. This year 2012 its been unusually cool here, i've only just started using the pool in May, purely due to heat loss probs to the ground mentioned above.

And yes I made my own on-top slabs using polystyrene 8 by 4 foot slabs encased in horticultural grade plastic sheet and seam welded with a hot air gun designed for the purpose, around 100 pounds for the gun. So my slabs cost me far less than the 1000 pounds commercial ones would have cost.

oh and btw, its feb 2013, i know now that the gas heater is only transferring 15kw to the pool water [rather than 30kw] this is purely because the heat exchanger i inherited, is running at half its labelled rating, because the manufacturers spec. likes to look good. with an inlet temp. of around 70 centigrade it can only transfer 15kw. so beware, err on the side of choosing, around double the heat exchanger rating, or double check that the inlet-to-pool temperature difference [and water flow rate] will achieve the required heat transfer.

re. robtig1, in wales uk we only really get lots of sun occasionally, and the prob with the collectors is that they produce maximum energy when the sun's already heating the pool anyway. So in midsummer long days yes it can add a fraction of a degree c,,.. but it tends to get lost overnight or by subsequent dull days.

I have about 10 square metres of the black ribbed rubbery collectors, the pool area is 30 square metres. I'd say I need at least 30 sq metres to make much difference over all. and my pool is under a huge plastic greenhouselike structure, the collectors are at 60 degree angle inside that enclosed area, and pick up more heat [or rather, lose less heat to the wind] than if they were outdoors. Over all I'm not impressed by the manufacturers claims of 5 or 9 degree increase. Not in the average uk summer anyway.

Swimming Pools
Pool Heating
Meteorology and Weather

What temperature should an outdoor pool be heated to for comfortable swimming in cold weather or freezing temperatures?

I think you should just adjust to the temperature of the water.

I am a nationally ranked swimmer and I like the pool at 68-73 degrees.

At a temperature of 82, you should only be in the water for 25-30 minutes. I don't know how long you plan on swimming, but even 82 degrees to me sounds way to warm. I you decide what to do.

AnswerWe usually heat ours to around 85�F. In fact, in the summer, we consider our pool cool if it stays below 90�F (we live in Phoenix where 115�F is normal).

Also, while they say that a spa around 105�F shouldn't be used for more than 15 or so minutes by an adult, water at 85�F is safe for an indefinite amount of time.

Water Temperature A Sore Spot For Pool OperatorsPool temperature is one of the biggest sore spots for pool operators.

The answer is simple. If you are seeking repeat business, heat the pool at to a temperature the patrons will enjoy.

My recommendations are as follows: ''competitive swimming'' - the swim coach should determine the temperature ''hotels and resorts'' - 84 to 86 degrees is an ideal range ''athletic clubs or YMCAs'' - it depends on who they are catering to. If they cater to lap swimmers, 82 degrees is a reasonable temperature. For casual swimmers, near 84 degrees is better. Warmer than 84 degrees will be too warm for lap swimmers.

Bill Soukup President Commercial Pool & Spa Supplies Inc. www.commercialpool.com

Pool Care and Cleaning
Pool Heating
Solar Power

How do you put on a solar cover?

Lay your solar cover, bubble side down on top of the pool

Just want to add, we bought a solar cover for our above ground Intex pool. The cover completely covers the pool and keeps the pool water very warm (which is the purpose). However, you need to double your chlorine to keep from getting algae. It's almost like having a spa. When I lift the solar cover, there is condensation on the cover and steam coming out. So you need to really watch your chlorine levels.


You may also want to try using a liquid solar cover. They are really easy and relatively inexpensive...best of all, you don't have to put them on and pull them off all the time. Check out www.liquidpoolcovers.com

Pool Heating
Painting and Staining

Does paint color affect the temperature of a pool?

Yes, it does.

Heating Ventilating and Air Conditioning
Pool Heating
Pilots (aviation)

How do you keep the pilot light lit on a pool heater?

The flame should generate a micro amount of voltage which keeps the burner going. If the burner won't stay lit the problem could be caused by a lazy pilot generator, dirty wire connections, high wind conditions, or even something more serious or clogged. Your best bet is to have a trained service technician from your local swimming pool company come out and give your heater the professional testing it deserves. You will find a properly tuned and installed heater will save you quite a bit these days with the high cost of fuel.

Swimming Pools
Pool Care and Cleaning
Pool Heating

Does the bubble side of a solar pool cover go up or down?

Personally, I disagree with the logic used by those above. If the bubbles are up, there will be larger surface area to absorb the sun's heat. Increased levels of heat absorption seems more important than the rate of heat transfer, especially when considering the fact that heat transfer takes place almost instantaniously.****i have tried it both ways, bubbles up or down. makes little or no difference heating. with bubbles down, though, it is easier to clean debrie off the cover and keep it clean.

Swimming Pools
Pool Care and Cleaning
Pool Heating

What do you put in the pool to eliminate the rust when you fill a 15' x 42 inch pool with city hard water?

AnswerIt's very tough to remove rust stains if they are already established. It sounds like you have an aboveground pool, possibly purchased at Canadian Tire. You can use a sequestering agent (such as Aqua Min-Out) to keep the rust-causing minerals in solution (in the water) so that they don't stain the pool. To remove existing stains, you can try dropping some granular PH Minus (PH Down) into the water so that it settles onto the rust spot or spots. Obviously, this will only work on the bottom of the pool and if the water is still. In addition, ensure that you have your water professional tested to determine the Free Chlorine, pH, Total Alkalinity, Calcium Hardness and Stabilizer levels. Poor water balance can cause problems with the liner, and if the alkalinity is low, any metal parts (in the pump, etc.) will rust. AnswerTry BioGuard's product called Pool Magnet. It is great for removing various metals from the water.

Just a little added detail you can also purchase a filter that screws onto the end of your hose so the water is filtered clean of minerals before it even reaches your pool water.

Swimming Pools
Pool Care and Cleaning
Pool Heating

Why would a pump get dirt in the bottom of a pool?

The way you describe your problem sounds alittle familiar. Im know pool specialist but im trying to become on so ive picked up alittle bit of knowledge lately. As you mentioned you have changed the sand in your filter already which is the first step when you are getting dirt etc... back in your pool whilst the pump is running. Although you have changed the sand you may have put too small of a sand particle in your filter. I dont know much about EZO sand but it is a possibility that the sand had little clay particles attached to it and as the sand has become wet the clay has separated. Which could be causing the clay deposits in your pool. Your best bet is to find out from the person who installed the sand whether they have any problems like this happening. Also ask how fine the sand was, if its too fine a sand for the filter you have. The pump will just circulate it through your filter and pool which is not what you want. Hope this has helped alittle. I have had this problem in the past. When the sand was added to filter it is very important not to get any sand into the top tube. It must be covered. If sand gets in there it will certainly cause this problem. Also any cracks inside of filter will cause same thing.

It may be too, not enough sand was added to the filter, too much sand added or you may have a damaged lateral. These only if it is sand at the bottom of pool. Dirt and other small debris is another situation. If the latter, it could be a part of the b/w valve assy internal parts that are either loose or missing. On the other hand if you have a DE filter you may have some damaged grids. They have to be removed and replaced. The "dirt" is actually DE dust and fine particles of dirt that accumulates over the weeks or months.

Swimming Pools
Pool Heating

What is the ideal swimming pool temperature if you have 30-34 Celsius outside air temperature?

30C-34C is about 86F-93F! That temp will generally feel too warm for most people in a pool.

A better temp that would suit more people would be around 27C-29C or 80F-84F. The water will still feel warm but still be refreshing when you're swimming.


I think for 30-34 degree centigrade ambient temperature, the pool temperature should be around 81 F (approx. 27 degree C). This will make body feel fresh.

For a ambient temperature of around 25 degree C and below, the pool temperature should be slightly higher at 30 - 32 deg C.

I run a health club and have always had my pools at the following:

Depending on the water temp the ambient temperature should be 1 degree higher. Ideally the pool should be 29 - 30 with an ambient temp of 31 degrees

You don't really want pool water any higher than 30 as it starts to cause problems with the water.

Higher temps will increase evaporation - causing the amount of dissolved solids to increase, it also means the disinfectant will be burnt off and the total alkalinity will also increase - this will cause all the pipes to fur up just like a kettle does.

Pool Heating

Can you get hypothermia from cold pools?

The answer is definitely! I am a lifeguard and we learn all about this stuff in training.

Pool Heating
Color Blindness

Is the best color of solar cover black blue silver or clear?

Thus, a clear solar cover would be the best cover to use for heat gain, and a dark blue solar cover would be the best cover for heat retention. And the light blue solar covers appear to be a happy medium between heat absorption and retention. It's also the most popular color.

Home Electricity
Swimming Pools
Pool Heating

How can you contact Teledyne Laars to get a manual for an LLG heater?

I cannot find a current listing for Teledyne Laars. As far as I can tell, Teledyne and Laars separated, Laars joined up with Waterpik and then got reorganized under Jandy. www.jandy.com now has the Laars Lite2 line of pool heaters with the LG model almost identical to the Teledyne Laars LLG. You can access the manual at http://www.jandy.com/pdfs/H02359-.pdf . Jandy also has a parts list for older discontinued models.

Swimming Pools
Pool Care and Cleaning
Pool Heating

Will liquid solar pool cover keep out dirt?

Unfortunately no, liquid pool covers cannot help with any debris (dirt, bucks, leaves, etc). You have to decide what is more important, the ease of using a liquid cover vs the debris catching ability of a plastic cover. There is also a price differential, of course. Sometimes a net and a good skimmer/filter will do the trick!

Good luck!

Ford Aerostar XLT
Heating Ventilating and Air Conditioning
Pool Heating
New Jersey

Will a 130K BTU heat pump provide adequate heating for a 20x40 pool in New Jersey?

It depends on when you want to swim. If you are looking to extend your swimming season a few months, like from May to September and/or you would like to raise your water temp 10-15 degrees than a 130K heat pump will do the job. The most important thing you can do it to use a solar cover. The heat pump will only raise the temp of the pool approximately .5 to 1 deg an hour and only if the temperature is above 50 degrees or so. So it will take 24 hours to get the pool comfortable and than with a 6-8 hour pool pump run time you should be able to have the water a comfortable 85 degrees or so. Without a solar cover the evaporation will be much higher and you will need to run the heat pump for 10+ hours a day to maintain the desired temperature. If you want to have your pool 90+ degrees regardless of the outside temp and you want it to heat up very quickly, than you definetly want a propane or gas heater. The answer is no. A heat pump requires heat to pump. NJ probably gets a little cold doesn't it? Therefore, no heat to pump. Depending on wind conditions, I would go with a Laars 400LX/LT. HM Louisiana

ANSWER: Stay with the Raypak.

Pool Heating
Home Appliances
Electrical Troubleshooting

What could be the problem with a Teledyne-Laars pool heater if the pilot light lights with no problem and the valve is ON but the burner will not start up?

On the inside of the heater cover, and within the documentation shipped with the heater, there should be a diagram of the control circuit. These heaters will not operate if the pump is off (pressure switch), if the "fireman" switch is off (a switch generally inside the pump timer that disables the heater about 15 minutes prior to turning off the pump), nor if both of two additional high temperature limit switches are activated (models will vary). The fact that the pilot is lit indicates that the pilot generator is OK. If you can turn the burner on by shorting the control circuit manually (using a jumper wire) the problem is in on of the safety limit switches, or in the thermostat itself. Good Hunting!


A pilot generator may have enough power to operate the pilot ,however not be sufficient to operate the main valve as well, this is quite common.

The way I test a millivolt system of any type is I have a AA battery holder from RadioShack with a positive and negative lead, I disconnect the pilot generators 2 leads and replace them with the AA batterys. The battery is 1.5v it wont hurt though, but if the gas valve wont open and you do get voltage to the gas valve terminals for the main valve, the valve is either bad or stuck, an amp draw will tell you if its trying to work or shorted perhaps if excessive.

There are a limit and on off and thermostat on this unit I believe as well .

Swimming Pools
Pool Building and Repair
Pool Care and Cleaning
Pool Heating

How do you stop your pool from sinking?

I have a sinking problem with my pool too. The technician says the way to fix it is to drill deep holes around the sinking side and put cement in to support the pool. It is a big job. Takes a couple days.

Pool sinking?

Is the pool sinking The wall of the pool and coping are one unit, the concrete deck is also a unit, they move independent of each other, with a caulk joint between each. That joint must be maintained. Your pool pro has the right stuff. You wont find home caulk at the DEPOT.

Yes I have seen well over 6" inches of change and in

very cold spells especially in the wet years on pools, generally they go back into shape, but caulk maintenance is key. The deck is moving usually gives the illusion of the pool sinking. getapool.com goood swimming take care

Swimming Pools
Pool Care and Cleaning
Pool Heating

How long should your pool pump and heater run each day?

Let's start with the pump first:

The pool pump needs to run long enough each day to filter all of the water in the pool at least once. Twice is better. Three times or more is wasting electricity. Some people will debate these numbers, but they are a good rule of thumb and an excellent place to start.

So, first calculate the number of gallons of water in your pool (G). Next, find out the flow rate of your pool pump in gallons per minute (F). Last, divide the gallons, G, by the flow rate, F, to get the number of minutes you need to run the filter to turn (filter) all of the water once.

For example, if I have a 5000 gal pool and a pump rated at 25 gallons per minute, it will take 200 minutes (or about 3 hrs and 20 min) to filter all of the water once. Multiply the time by 2 if you want to turn the water over twice (6 hrs, 40 min).

Next the heater;

You can spend a lot of time trying to calculate the time required to maintain a certain desired temp each day, but the number of variables (desired water temp, min and max air temp, cloud cover, wind, geographic location, time of year, etc...) make it very difficult.

I would suggest that you start with the heater on for an hour per day and then add an hour each day until the water temp reaches the desired temp. Then, you might have to adjust slightly backward (subtract 30 min) to keep it at that temp daily.

Pool heaters typically have a thermostat control that prevents overheating and waste of energy. They will generally cut-in when the water temperature drops by 1-2 deg.C below setpoint, and then go into standby mode when the desired water temperature is reached.

If you have your heater in the same circuit as your filtration pump set, then the available hours to heat your pool are limited by the hours you determine which may be insufficient in mid-winter depending upon heater capacity.

If a separate heating circuit is provided, then just leave the heater on standby mode and it will self-determine when to operate providing water flow is present.

Heater capacity, climatic factors of wind, sun, ambient temp, etc. and decision to use a pool blanket will affect the number of hours that you need to run your heater.

The first answer above is all well and good if you can get the water particles to all line up for you so they will all go throught the filter in the calculated time. In my experience, water particles are notably uncooperative in this regard.

It's completely unnecessary to run ''all'' of the water through the filter, especially if you have a chlorinator or brominator (automatic chlorine or bromine dispenser). A good rule of thumb is: if the water looks clear, it's just fine.

The pump on my 18' X 36' pool (about 25,000 imperial gallons) runs twice a day for 3 hours each time. It's never been a problem.

As for the heater, in general, you set it for the temperature you want and, as long as the pump is actually running, the heater will automatically turn on and off as needed to keep it at that temperature...just like the furnace in a house. For my pool, the gas heater I have will raise the temperature by about 1/2 degree F. per hour. Unless your pool is outside in the winter, the temperature should not vary too much between the times when the pump (and therefore, the heater) is on.

By all means, get a pool solar blanket to keep the heat in when the pool is not being used. You're trying to heat the pool...not the back yard.

The heater answer is simplest, so let's look at that first. How long should a pool heater run daily? As needed. The bottom line question is: how warm do you want your pool? Once you determine that need, the heater will fire as needed. To conserve energy & cut costs, turn the thermostat down to maybe 78 or 80 degrees F. (about 25 C). Keep the pool exposed to as much natural sun by cutting back overhanging tree branches, etc. Finally, as has been noted, use a solar blanket or one of the liquid solar blankets (about 75% as effective without the hassle of taking it on or off - Ecosavr solar fish or the Solar Pill are 2 products available).

When it comes to running the filter, the answer needs to look at how much use the pool gets (more swimmers equals better circulation & less dead spots in the pool) as well as environmental conditions.

The bottom line questions for the pool owner are: how clean do you want your pool? and how much work do you want to perform? If you want to minimize YOUR work, then the filter system will need to run longer. If the filter system is running more, it is doing more of the circulating and debris removal than you would be. We typically recommend a minimum of 8 to 12 hours DAILY as long as the pool is open and running. The pool owners with the best looking water and the least amount of pool water problems are those pools that are filtered/circulated/treated 24/7.

In order to conserve electricity and therefore costs, having a well running timer, running 3 time periods of 4 hours each period at 3 separate intervals daily acccomplishes several things: 1 - keeps the water moving (after the filter shuts down, it takes roughly 4 hours for the water to become "still"); 2 - provides the "turnover" to properly filter as much of the water in the pool as possible: it typically takes about 4 turnovers to filter 98% of the water in the pool (remember those dead spots where there is minimal or no circulation); 3 - saves money by operating during "off peak" electrical hours (usually at about a 30% or more savings) - most pool owners can schedule about 8 to 10 of these hours during "off peak" times.

Pool Building and Repair
Pool Care and Cleaning
Pool Heating

What are the little black and white particles in the pool?

debris from trees, rain. ect!

Swimming Pools
Pool Care and Cleaning
Pool Heating

Do you remove a solar cover at night?

A solar cover will help keep the heat it gained from the sun that day in your pool. Evening temperatures are typically lower and the cooler airs 'pulls' the heat out of the pool. You can't see it except at a pool with a heater...you see like a 'fog' over the surface of the pool. So leave it on overnight to maintain the heat in the water

Swimming Pools
Pool Care and Cleaning
Pool Heating

How warm should swimming pool water be for a baby?

General info on pool temps:

Most people are comfortable in pool water at about 80F on the low end. Almost everyone is comfortable at 85F. Some people will find a 90F pool starting to be too warm.

Babies, on the other hand, lose a lot of body heat to the water and do not have a fully developed temperature regulation system. Therefore, I would recommend a temp in the high 80's (87F) to the low 90's (92F). This should be comfortable enough for you and your baby to have a good time.

Be careful to watch for signs of coldness: shivering, loss of color in extremities like fingers and lips, etc...

Hope this helps...

Pool Heating

Do you need a pool heater in a warm climate?

Depends on what you want out of your pool ...

If swimming only during the hot months is okay, then you don't need a heater.

However, if you would like to extend your swimming season, you should consider a heater.

A solar heating system can extend your swimming season a couple of months earlier and a couple of months later, but probably can't heat your pool year round. For example, here in sunny Southern California, I can comfortably swim from March through October (with water temps of over 80F).

A gas or other fuel-based heater can provide year round swimming, if desired.

Pool Care and Cleaning
Pool Heating
CD and DVD Drives

What is the best way to repair rips in a solar blanket?

I used a hot glue gun with acceptable results. Made it through the summer.

ANSW:: there are not many products on the current market to do adequate repairs to solar covers. The big problem as with most remodeling, refurbishing or repairs is the prep. You need to clean and dry the cover completely before a product will work. All solar blankets are heat welded at the factory and even a portion of those welds fail. If the cover has deteriorated to the point of disintegration then nothing is going to work even temporarily. There are some products that will get you thru the season or will only last a month or 2 and fail. Best to bite the bullet and consider a new cover for next season. You can get possibly 4 to 6 month more out of a cover if you are a fanatic about cleaning it, protecting it from the sun when not in use, storing it in absolutely clean, protected and dry conditions. Covering the cover when not in use during use of the pool daily will help but measured in time of life for the product it is minute. k

Pool Care and Cleaning
Pool Heating

Is it too expensive to heat a pool every day?

It depends. Your heat pump may be undersized. Using a pool cover will keep the heat you make from being lost at night and cut the cost of operation in half. It is more efficient to run the heater only during the daytime. You may want to consider using "solar" as a supplemental heat source.

Yes, if your pool heater has been wrongly sized to your pool configurations you will end up spending more for your gas bill than someone with the exact same pool and use habits as yours but they have a much larger BTU heater. The larger heater will heat the water faster or in less time than a smaller heater would and would have better recovery as pertaining to water temps. Longer heater run times require more gas consumed. Expense, even for those who can afford it, is of concern for most. Depends on your priorities and budget.


Hold on now, the amount of heat required to keep a pool at a given temperature won't depend much on the size of the heater, but rather the total amount of energy used. The heater should be an appropriate size running for an appropriate length of time, but your total cost will mainly be determined by pool size, temperature desired and heat loss factors. If your pool heating bill is too high, cut the temperature a little and check the timing relative to when you actually use the pool.


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