If galvanized piping was uset to plum the house, it may have rusted shut, an easy fix would be to run a new line in copper or PEX from the water heater to the valve
It all depends what faucet is running if it is a kitchen or lavatory faucet it would be roughly 3 gallons if it was a tub and shower faucet it would roughly 15 gallons
No conversion, it would need to be replaced with a single handle faucet.
Replace the shower valve (faucet). I would call a plumber to check it out. Because there may be another reason, it depends on other things besides faucet. Like a crimped water line under slab floor, if you have copper water lines, i have seen the cooper pipe go all the way into a tee and block off the outlet to the faucet. If it has been like i have mentioned above it would have been like this since day one. It would help if people would tell how old there house is and how long has the problem been going on. And yes it could be very much the faucet itself if it just starting do it. IN ADDITION: This also depends if the shower has a mixer or tap (faucet) installed, as the question didnt stipulate this. The rest of the house could have taps and the shower have a mixer. Mixers need a minimum pressure of 400 kpa from the hot water tank (geyser) to work. If the hot water tank is of a lower pressure this would explain for its poor performance.
New pressure balance faucet or you can install a pressure balance valve in the water lines behind tub or if you have a crawl space you can install it on the water lines there. But install only too the lines to tub faucet. And they are not easy no matter where you install. I would just tell everyone not to use any water till you are done with shower.
You should purge all your water pipes of built in sediment. Don't forget, you are drinking the water too!
The faucet is clogged
First make sure that the hot and cold supply lines (the plumbing) aren't backwards (hot should be on the left as you are facing the faucet) or that someone accidentally ran two hot lines. For the problem to be in the faucet itself you would have to have a single handle faucet. If this is the case the control valve is broken and should be replaced. Three handle Left= Hot Water Flow. Right= Cold Water Flow Center= Controls whether the water comes out the shower head or tub faucet. Two handle Left= Hot Water Flow Right= Cold Water Flow (Diverter Valve is elsewhere if it's a tub/shower) Single handle One handle controls both water pressure and temperature
form_title= Moen Shower Faucets form_header= Install a Moen shower faucet in your home! What is the size of your shower?*= _ [50] What type of shower head do you want to install?*= _ [50] What color would you like the shower heard?*= _ [50]
The water is probably collecting in the shower head until there is enough to overflow which would cause it to drip faster for a bit and then go back to a steady rate.
A clogged aerator on the end of the faucet would cause the water flow to decrease in that faucet.
It would help to know what brand and if it is a pressure /temperature balance type also AKA scald protection
The hot water faucet starts with h. Or a brand name would be Hansgrohe.