Plumbing Questions? Ask a Plumber for Answers ASAP
Hello This sounds like it could be some thing other then the heater,have you tested to see if water at heater changes temperature or just at faucet.
We checked the heater which does not change temperature but when a hot tap is turned on elsewhere it appears the hot water pressure at the shower is reduced. Will a pressure balance mixing valve on the shower correct this and will it work well with our on demand system?