ᐅ How to Perform a Hydraulic Balancing of a Radiant Floor Heating System Yourself?

Hi,

we have been living in our newly built house for a year now, so I thought it was time to optimize the underfloor heating for this second winter.

There are two heating manifolds on two floors, each with several heating circuits. Some of them are controlled by actuators and electronic radiator regulators (ERR), others are not. Overall, the ground floor tends to be slightly too warm, and the upper floor a bit too cool.

I understand the basic concept of balancing: open everything, lower the heating curve, and then fine-tune. But how do I do this precisely?

• Topic "Opening everything": Where I have room thermostats, I set them to the maximum. This causes the associated actuator on the heating manifold to open the circuit. But I also have circuits without actuators. Do I need to open these as well? Do I just remove the orange cap and loosen the screw with a wrench (see photo)? Do I need to do anything with the flow meters in this process?
• Topic heating curve: How do I handle this for the two floors? There is only one heating curve. Do I turn everything up at both heating manifolds on ground and upper floors at the same time, or do I proceed floor by floor?
• Topic fine-tuning: In the end, do I close the circuits where necessary that I opened under point 1), or do the circuits stay open, and the adjustment is done via the flow meters (this would make more sense to me)? So, at the end, do I have permanently open circuits that I adjust with the flow meters / flow rate?
Can anything go wrong if I open everything fully?

Thanks a lot!!

Should the hallway and utility room be kept extra cold?
If yes, then of course leave them as they are!

Hello, the picture is just for illustration purposes so you can tell me when and what to adjust to make a proper calibration.

Currently, the ground floor (shown in the picture) is very warm with a low flow rate and a heating curve set to 36°C (97°F). The hallway is also warm! The goal would be to lower the heating curve and increase the flow, including on the upper floor, where it is currently too cold.

So please don’t focus on the current settings; I think the system needs to be balanced at both the top and bottom of the property. That’s why I have some specific questions.

I would do it like this:

• Lower the actuators
• Turn up rooms that are too cold
• Turn down rooms that are too warm
• If all rooms are too cold, raise the heating curve
• If all rooms are too warm, lower the heating curve

Only adjust things you understand.

Hello,

do you want to continue using the ERR? If so, you need to open the associated thermostats fully. If not, you can also unscrew the actuators.

Procedure:

• Fully close the differential pressure valve
• Fully open all circuits
• Under the orange covers, there is a screw that can be adjusted with the corresponding key. Only unscrew the orange caps loosely, otherwise they push the pin into the valve and lock it
• For valves with actuators, open the thermostat fully
• Wait one day to bring all rooms to the target temperature
• Identify the coldest room
• Raise or lower the heating curve by one degree
• Wait one day to check the coldest room again
• Repeat steps 4 and 5 until the temperature in the coldest room is correct
• Reduce the other rooms via valve settings or thermostats
• Wait one day to check the temperature of the other rooms again
• Repeat steps 7 and 8 until the temperature in the other rooms is correct

The procedure above takes a long time. If you know the lengths of the circuits, you can also start by reducing the short circuits to the minimum and fully opening the longest ones. Adjust the rest roughly to intermediate values. Over time, you can fine-tune individual rooms until the comfort heating level is satisfactory in each room.

The coldest room determines the heating curve. If the coldest room is a bathroom and you have a separate radiator installed there, you should not use this bathroom as a reference.

During all these adjustments, keep an eye on the heat pump’s flow rate; the minimum flow rate must be ensured at all times.

Best regards

36 degrees is too much.

Procedure: Turn off the actuators. Set all heating circuits to maximum.
Then wait 1 day. If all rooms are too warm, lower the heating curve. Wait 1 day. Repeat this until one room is no longer warm enough.
Then reduce the heat in the room that is still too warm and the warmest. Wait 1 day. If all rooms are still too warm, lower the heating curve again. If not, reduce the heat in the warmest room that is still too warm. Wait 1 day.
Keep doing this until all rooms have the exact right temperature.

The ground floor tends to be warmer because it has lower pressure loss due to the shorter pipe length from the heat source to the manifold.

You have chosen the right weather. You need patience. A lot of patience. Lots of trial and error. It is also important to keep heating 24/7. In new buildings, lowering the temperature or switching off at night no longer makes sense.

If you have questions: ask