Tankless water heater problem! Propane

bamboo · 01-27-2021, 10:04 PM

Tankless water heater problem! Propane
2014 Via 25P,
the water came out warm, not hot at all, but if I am connected to the City water, it is super hot! what seems to be the problem? only slightly warm if I use the fresh water tank by water pump pressure, but if I am connected to the city water without the water pump, it gets super hot! please help. thank you!

bamboo · 01-28-2021, 12:00 AM

on city water it works fine, so I think is the problem of the water pump. I will check the pump tomorrow and post the results here, and if anyone has better ideas, please help.
thank you

**creativepart** · 01-28-2021, 08:34 AM

Perhaps, and this is a guess, you have a winterizing valve for the hot water bypass partially open?

That might cause such an issue.

The pump is plumbed to the fresh water tank. It pump’s all the water the same. It cannot do one thing with cold water and another with hot water. So I don’t see how it could be the pump.

al1florida · 01-28-2021, 04:22 PM

What make & model of tankless water heater do you have?

Tankless water heaters I believe depend on sensing water flow to light the propane. If your water flow causes the water pump to cycle on and off the water flow will stop through the water heater and the heater will turn off the flame. In the water heater we had, once the fame went off, the heater went through a cool down cycle for some 15-25 seconds before the flame would come back on.

We frequently dry camp or boondock or park w/o having hookup to sewer, so we usually turn on the sink faucets really low. This causes our variable speed water pump to lower the pressure to almost off. This caused us to have alternating warm water going to cold water and back to warm.

We had Girard tankless water heater that I removed and installed an old fashioned propane/elect water heater with a tank.

bamboo · 01-28-2021, 05:05 PM

I also have a Girard tankless water heater.
my sink next to the shower can get hot water, but not the shower! shower only gets warm!

misteracng · 01-29-2021, 04:12 PM

Quote:

Originally Posted by bamboo

on city water it works fine, so I think is the problem of the water pump. I will check the pump tomorrow and post the results here, and if anyone has better ideas, please help.
thank you

So on tank water with the pump, you can get hot water in your bathroom sink, but the shower is only getting warm? On city water you get really hot water at all outlets?

bamboo · 01-29-2021, 09:12 PM

yes, I sometimes get hot water on sink next to shower, but shower not hot, today I tried again, and sink next to shower also not hot, so it is a intermittent problem!! but I think it should be the pump pressure or water flow issue, I get about 1 gallon per min on the sink, and less than a gallon in the shower. I am waiting for a 2 gallon accumulation tank, I was going to add that to the plumbing, so I will see if that will help with the problem.

71_340 · 02-04-2021, 06:26 AM

While connected to city water you have most likely a higher water pressure (around 60 PSI) vs what your pump puts out (45-50 PSI). The Girard water heater depends on good water flow to work correctly.

Take a look in your water heater owner's manual, it shows you how to adjust the flow valve. Once you do that I would recommend using an inline pressure regulator when hooked up to city waterso you operte at around 50 PSI, no matter what the water source is. Hopefully that solves your problem.....it should.