Hot water not so hot

[PaulNC]

Maybe someone can explain what's going on with my hot water.

40 gallon propane water heater 7 years old
hot water temp now only 93F degrees with tank dial set at HOT (120F) - no problem until a few days ago
well water - temp fluctuates with pressure from pressure tank - as pressure decreases water temperature drops - as pressure increases water temp rises
Having a bathroom remodeled and some plumbing lines were moved the day that I noticed the temperature changes

What could be causing this? I can easily set the water heater to a higher temperature but wonder what's going on.

Any ideas?
Thanks

 

[pasadena_commut]

Seems like reviewing which plumbing lines were moved (and rearranged?) would be a first step. If I had to guess, there is a cold line now attached to a hot line, directly or indirectly.

 

[PaulNC]

That does sound like a possibility, but the only lines moved were to relocate the shower fixtures. The supply lines were cut and then extended to a different area of the shower.

Maybe turning the main water supply line off and on a couple of times caused sediment to flush from the water lines into the water heater tank? Even if that happened how do we explain the temperature change with pressure change?

 

[Rickyman]

Wild guess, you have a Delta rough in shower valve and the cartridge isn't in it yet.

 

[PaulNC]

Yes, that was the problem. We have hot water again.

Thanks

 

[MicEd69]

Glad you found the issue, and you may want to look into a Cycle Stop Valve (CSV) to better your water system. A CSV provides a constant pressure to your fixtures, greatly improves well pump life, and saves energy costs, just to name a few of its benefits.

 

[Valveman]

Thanks MidEd. That is a very common problem with instant water heaters on well water. I heard it called a Cold Water Sandwich. Lol! With a 40/60 pressure switch the flow to the water heater is good when close to 60 PSI. But when the tank is draining down to 40 there is not enough flow to keep the heater going and the water gets cold. As soon as the pump comes on and the pressure gets close to 60 again, the heat is back. A Cycle Stop Valve will stop the pump from cycling by holding 50 PSI constant for as long as you are in the shower. This not only eliminates the cold water sandwich but the constant pressure from the CSV is so much stronger people tell me they no longer even need soap.