Water heater Installation with recirculation pump and thermostatic valve

[FLhome0wner]

I'm a home owner located in Florida (IPC/FBC/FRC building codes), I'm installing a new Rheem hybrid water heater that I've had in my garage for a while as I remodeled the rest of my house. I attempted to plumb this per all applicable codes, and manufacturer recommendations. I have concerns that I don't have the recirculation hot water return to the cold return properly heat trapped and I have have water rising from my recirculation line going up to my thermal expansion tank and my vacuum relief valve. Is this something to be concerned about?

Also, so far I haven't been able to get my recirculation pump to be able to pump water around the loop quicker than 30 minutes (if it's even pumping). I estimate that the volume of my loop is 1.5 gallons and the pumps max flow rate is 2.2 gallons per minute. I think there is air in the lines, but it didn't get better when opening all the valves upstairs and running hot water.

Lastly, I wasn't sure how to interpret the code the the TPR valve drainage tube. I had some extra copper and fittings, so I used that. I installed it to the rim of the pan, which is ~2 inches tall. Code states it should be between 1.5-6 inches above the floor or flood rim of the receptacle. Does the pan count as the receptacle? Is the purpose of the gap for backflow prevention?

Anything else I should be careful concerned about with this installation? This will be inspected, I just haven't called the inspection yet.

I attempted to plumb this as follows while also meeting requirements for my plumbing codes: https://www.caleffi.com/usa/en-us/blog/temperature-creep-hot-water-recirculation

I've added a photo of it's current state and some in process photos.

 

[John Gayewski]

I can't see how everything is piped. But you need to bleed the recirc line by shutting the valves to we everything but the recirculating line. Meaning the water can only take the path of cold, water heater, fixtures, pump, back to heater. That line needs to have the air cleared along with the other lines. Then you can run the pump and fixtures. When the pump runs everything should get hot.

Using a heat pump water heater may be useless considering the heat pump might not keep up with the recirc feature, in which case the electric backup kicks on and you just have an electric water heater.

 

[Sponsor]

 

[FLhome0wner]

I can't see how everything is piped. But you need to bleed the recirc line by shutting the valves to we everything but the recirculating line. Meaning the water can only take the path of cold, water heater, fixtures, pump, back to heater. That line needs to have the air cleared along with the other lines. Then you can run the pump and fixtures. When the pump runs everything should get hot.

Using a heat pump water heater may be useless considering the heat pump might not keep up with the recirc feature, in which case the electric backup kicks on and you must have an electric water heater.

Once the system appears to be operating I'll be using a pump controller that senses temperature and flow rate sensor (https://smartrecirculationcontrol.com/) to reduce the amount of recirculation. I think that takes care of the issues with the heat pump as it won't recirculate a ton of water and not very often.

 

[Fitter30]

What's the model and brand of the recir pump. That spring check might be creating to much head. Could also crack the bottom union of the pump to see if it's air bound.

 

[FLhome0wner]

What's the model and brand of the recir pump. That spring check might be creating to much head. Could also crack the bottom union of the pump to see if it's air bound.

It is a Grundfos UP10-16-PM-BN5. The check valve is a Matco-Norca™ 525T04LF 525TLF. There are also check valves in the thermostatic mixing valve (Caleffi 521619AC).

https://www.supplyhouse.com/Grundfos-98420210-UP10-16-PM-BN5-LC-1-2-FNPT-Comfort-PM-Pump

Matco-Norca™ 525T04LF 525TLF In-Line Check Valve, 3/4 in, Thread, Bronze Body, Lead-Free | First Supply

Matco-Norca™ 525T04LF 525TLF In-Line Check Valve, 3/4 in, Thread, Bronze Body, Lead-Free

www.firstsupply.com