Simple Question: Is there something to regulate water pressure/volume such that the water heading into the HWH and the water heading to CW into the house is maintained the same?


I have been using a Boiler to heat the water in my house for a couple years now. This is w/o a tempering valve. I decided I would finally get a Electric HWH. I made it a point to solder in copper and valves such that I could set any of the following:

Pump > Electric HWH > House HW
Pump > Tankless Coiler on Boiler > House HW
Pump > Tankless Coiler on Boiler > Temp Valve > House HW
Pump > Tankless Coiler on Boiler > Electric HWH > House HW
Pump > Tankless Coiler on Boiler > Temp Valve > Electric HWH > House HW

(Currently have a bypass installed over the Electric HWH to test these HW valves/pipes.)

I plumbed a CW and HW lines out the window(3/4 pipe as is all the copper) to test this before I plumbed it into the house. When I first turned on the system I set it to bypass the boiler and HWH(yet have water flow into these soon to be HW pipes. There was NO water coming out of the HW pipe only the CW pipe.

I stuck my finger on the CW and hot water came out.(Not actually hot by will be once I turn on boiler & HWH)

I stuck a 3/4 to 1/2 Reducing coupling on the CW and water would come out both. The HW and CW now had water pouring out the window but HW is still extremely week pressure.

My only thoughts... There is a 20ft run of CPVC that is horizontal, one end goes to CW for the house and the other toward the pump. This is where I tapped in for the HW supply for the Boiler/HWH and it's a T that faces up and rises about 6 feet. Is the water just having to much fun running horizontal that is doesn't want to make the climb into the copper jungle? Would a Upflow T help?



Edited 1 times.

With that valving configuration, there is no way we can diagnose it because we would have to see how the valves are adjusted. But, if you have pressure going in to the water heater(s), somehow, it should come out without doing anything to the cold pipe.

Edit note: The valves arn't actually representing open or closed, just of their locations.



Edited 1 times.

Put a by-pass like you did at the WH on the boiler. Lose the valves around the thermostatic mixing valve, and move it to where the hot and cold enter the house. Make sure the boiler by-pass allows for draining the coil and leaving it open to atmosphere, so you don't burst the coil.

Didn't have to change anything. Turns out there was no back pressure from the Cold lines considering I had hung the mains open out the windows. Once I plumbed everything back in it works great.

Was a great feeling calling the oil company and having them change my budget dramatically!

Running the water through the mixing valve is fairly important. Especially because you're on a well. It allows you to raise the temperature of the water, in the water heater to at least 140*. This is the recommended temperature to kill bacteria.You get the fringe benefit of increasing the output of the heater, without scalding anyone.