Aah. It's gas. The 750mv makes more sense now. I figure you're trying to hook up the gas control valve. You should have a supply, some sort of controller, and the valve. If you wire them in series, they should work. However, I'm running off very little information. If I knew what exactly you had (As in the electric devices you are trying to wire) I could go into more detail.
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.
Check that you are getting voltage from the thermocouple. You should see about 600 millivolts.
go to their website and support and download it
Pool heaters are needed to help keep the pool water at a comfortable temperature. A Teledyne laars series 2 model esg pool manual is usually available with the manufacture.
You might want to try Jandy.com k
Try this link www.jandy.com Ken
Try google Jandy.com
Here is the file http://i.poolproducts.com/pdf/XL3_manual.pdf
I was told by Teledyne Laars that your pilot generator needs to produce at least 500mv to open the gas valve. Mine makes 350mv and will not open the valve. Hmm, I think that should be nearer to 600 mv - 700 mv.
Write or inquire thru that web site for a manual to be sent to you. k
You can find every part you need for your boiler at gasboilerspareparts.com
Probably a bad sensor. Have a professional diagnose the problem. It can be very dangerous for untrained to work on gas appliances.
Use the manual provided with the heater. Each heater has somewhat different controls etc. If everything is already hooked up you may just have to turn a switch or two and turn up the thermostat.
Lighting this heater appears to have a number of warning messages associated with it. It is typically best to go to the source for such things, so see the link below for the manual PDF file. Look at page 29.
it makes sure the heater is shut down BEFORE the pump does. It is very important if the heater runs without the pump running the water will boil in the lines and burn out the heater. I know this because my electrician didnt wire mine correctly and that's what happened to me. BYE BYE 2,500 heater
Oder the part from the company, a different orifice
From what I have read, 500mV is not enough to keep the pilot light lit. Here is what I read on a different site: "You can check if this is the problem by measuring the voltage on the wires coming back from the pilot. When you have the red switch depressed, check the voltage (should be about 200mV). If there's no voltage, then change the thermocouple. The thermocouple will generate up to 750mV in a pilot flame. If it falls below 550mV it should kill the fuel source." Hope this helps.
Use the link below to look at a Laars manual to see if one is included.
Contact your local gas company. The phone number is on your bill. Free call.
If the leak is in the copper fins/heat exchanger : replace the exchanger, gaskets etc Not a job for someone who is not familiar with pool heater construction and service. If the leak is at the inlet or outlet you may have to remove those fittings and replace woth new ones.
It could be it. The pilot generator may be weak. The Valve could be defective. The High limit or other safties could also be defective. Could be corrosion on the connection. could be a water flow broblem. could be a weak flame
Spa not getting to temp? Could be a dirty filter. Could be a high limit switch or other component.
Assuming the heater is running properly, is sized correctly the filter is clean it could possibly mean that the run time for the pump is not sufficient. How long is the filter/pump running? The water returning to the pool may not feel "hot" to the touch and shouldn't. Ken
As the water begins to flow within the system, the components inside the heater compartment ( the pressure switch)senses that flow and if your heater is calling for heat it will fire. When that water ceases to flow those same sensors tell the heater to stop firing. Built in safety devices. Ken