ᐅ How to Properly Adjust an Air-to-Water Heat Pump with Underfloor Heating

It’s up to you. Either request the calculation or take out pen, paper, and a calculator.

However, it probably isn’t worth changing everything drastically right away. Electricity consumption tends to decrease a bit during the second or third winter. I would suggest monitoring the situation for a few more months.

Since this question has come up so often in the last few days, maybe someone could take the time to write down the steps for the hydraulic balancing. This way, even beginners can understand it.

Very good idea. I would be very interested in that. Probably many people are currently dealing with it because it really seems like winter is finally coming.

Mycraft schrieb:


The valves on the heating circuit distributor (HKV) should be roughly set according to the calculation (the better the calculation, the less work required). The actuators should either be completely switched off or left powered off in the open position.

Then you can fine-tune the flow rate at the valves.

M4rvin schrieb:

I don’t think anything was actually calculated here. So far, nothing has been adjusted either.

It seems there is no calculation at all, or at least none was provided. Without documentation, it becomes difficult. How else could he obtain important data such as pipe length, supply line length, pipe spacing, pipe diameter, and HKV connection details if the screed is already installed? He cannot calculate the required flow for the heating circuit by himself! The only option left is to measure return temperature and room temperature with the thermostatic radiator valves (TRVs) fully open (or with actuators removed). If room temperatures are consistent everywhere and the return temperatures are approximately equal, the hydraulic balancing is correct and he can proceed with the thermal balancing.

However, the total volume flow must be sufficient for the heat pump! Unfortunately, this is often not taken into account during hydraulic calculations, even by professionals. They usually rely on assumptions and do not even calculate the room-specific heating demand at the homeowner’s desired room temperature, nor do they consider the heat pump’s rated flow volume.

Likewise, homeowners often reduce the volume flow for the heat pump by frequently adjusting the TRVs, causing inefficient short cycling.

Some tips can be found in a parallel thread:
"Underfloor heating, it gets so warm in the house when the sun shines"

tomtom79 schrieb:

Since this question has come up so often in the past few days, maybe someone could take the time to write down the steps for the hydraulic balancing. That way even beginners can understand it.

That’s true. The thread "https://www.hausbau-forum.de/threads/bodenheizung-luft-wasser-Wärmepumpe-haus-zu-warm-wenn-sonne-scheint.33030/" probably deals with the same topic.

If one or two heating experts could team up to write a pinned tutorial that is also easy to understand for beginners – that would be AMAZING