ᐅ Hot Water Recirculation Line: Is a Check Valve Required?

Hello experts,
I have a hot water circulation line in my newly built semi-detached house, which I want to circulate only on demand using a Circon circulation control. However, when the pump is off, the return line above the pump still heats up.

The heating engineer believes that the pump must always run, so this problem cannot occur.
I don’t think that makes sense and I believe I’ve heard that a non-return valve is required in the circulation line.

It would be great if someone could clarify what the regulations require here. Thanks!

May I ask if you are achieving a KFW standard? Our builder’s heating technician explained to me that a hot water recirculation pipe would disqualify the project from KFW subsidies. It would be helpful to know if it was possible after all.

Unfortunately, I don’t have a solution for your problem.

A hot water circulation line is nothing special. We have it too, controlled by motion sensors in the bathrooms and by a switch in the kitchen.
The KfW isn’t interested in that either (aside from the fact that they never find out).

@nordanney That sounds interesting. May I ask how you wired it electrically? Are there one or two pumps (one for the bathroom circuit, one for the kitchen circuit)?

Thanks and best regards
klblb

@klblb
There is only one pipe, which also has only one pump. The plumber and the electrician have taken care of the details (the rough-in installations have just been completed). I hope everything will work out as planned.

Hi
When I installed the system myself, I planned to use a timer for the circulation pump. Running it continuously is neither necessary nor cost-effective. I installed a check valve in the circulation line.