Hot Water Heater Blasting Cold

[Wally]

I just had a new propane indirect water heater (works off my boiler) installed 2 days ago. I am on a well pump. It has plenty of hot water, but when taking a shower, every time the pressure tank kicks on, I get a blast of cool water for about 10 seconds, then the pressure tanks turns off and it is hot again for about 2 minutes till the next cycle. The plumber told me it may be dirt in the washer machine valves and to turn the water supply off to the washer and see if it cures the problem, but it still does it. I never had this problem with the old water heater. Anyone have any other ideas?

[Joe]

2 days ago. I am on a well pump. It has plenty of hot

a blast of cool water for about 10 seconds, then the

cycle. The plumber told me it may be dirt in the

if it cures the problem, but it still does it. I never

Call the installer back to get it right...it isn't your problem, it's his. He probably has some piping wrong or some such. Good luck.

Joe

[unclemon]

2 days ago. I am on a well pump. It has plenty of hot

a blast of cool water for about 10 seconds, then the

cycle. The plumber told me it may be dirt in the

if it cures the problem, but it still does it. I never

A friend and I installed a tankless water heater for his sister and had a problem. The water at the sinks was hot but the water temp at the shower/tub was cold. It was the flow rate. After adjusting the rate of flow through the water heater we had hot water at the shower/tub. You may need a pressure regulator on the inlet of your water heater to keep the flow rate constant. It seems to me that when your water pressure increases as the pump kicks in, the rate of flow through your water heater becomes greater than the what the heater can keep up with. A bucket, a stopwatch and some simple math can be used to determine the gallons per minute for your shower when the pump is on or off.

[8~{} Uncle Monster

[unclemon]

2 days ago. I am on a well pump. It has plenty of hot

a blast of cool water for about 10 seconds, then the

cycle. The plumber told me it may be dirt in the

if it cures the problem, but it still does it. I never

Duh! Wally, when I read indirect water heater, I assumed it was "tankless". You know the old saying about when you assume things........... Your heater has a tank doesn't it? In that case, pressure and rate of flow could the culprits but in a different way. If there was is restriction to the flow of water going into the tank, it might cause the problem. Is there a expansion tank on your water heater? Dip tube failures or the lack of one can cause also cold showers. I wonder if your heater's T&P valve is opening up when your pump comes on? Anyway I'm sure someone out there has seen the your exact problem before.

[8~{} Uncle Monster

[Wally]

installed 2 days ago. I am on a well pump. It has plenty of

a blast of cool water for about 10 seconds, then

next cycle. The plumber told me it may be dirt in the

if it cures the problem, but it still does it. I

Thanks. Yes, it is a 40 gallon tank. The plumber that put it in is baffled by the problem. He's coming to do so more troubleshooting today, but said he has no idea why it's doing it.