ᐅ Is it possible to optimize the heating system after performing hydraulic balancing?

Hello everyone!

I am encountering topics where I have very little knowledge so far, but now need to deal with them.
Basically, we have an air-to-water heat pump (Tecalor THZ 504) and underfloor heating.
Before the handover of the house, our heating installer performed a "hydraulic balancing," for which there is documentation, and this was apparently also important for the KfW funding.
Therefore, the plumbing consultant once told us that we should actually not change anything on the heating system ourselves / maybe even are not allowed to (?), because that was the basis for the KfW subsidy.

Now, of course, we live in this house and in practice have a few minor issues with the heating.
Overall, the temperature in the house was comfortable during the cold months. As spring approaches, I find the house slightly too warm. As far as I know, you need to adjust the "heating curve" a bit. Simply turning down the temperature manually probably isn’t sensible, because the heat pump controls the indoor temperature based on the outdoor temperature, and since it worked fine in winter, I assume something in this ratio is off. If I lower the temperature myself now, then I’d have to raise it again when it gets colder — that just doesn’t seem reasonable to me.

Furthermore, upstairs it is constantly too cold in the bathroom (significantly so) and a little too warm in the bedroom.
This is related to the fact that, in agreement with the heating installer, we always turn the room thermostats fully up (anything else would be wasting energy, as we were also told here in the forum). Otherwise, they keep clicking constantly, which is annoying (especially at night). In the bathroom, even fully turned up, there just doesn’t seem to be enough heat, at least from my perspective. The bedroom heats up quickly and becomes too warm; we actually prefer to sleep in a cooler room.

Is there a way to adjust this so that the bathroom becomes warmer and the bedroom does not get too warm, without turning down the thermostats? For example, by changing something at the manifold?
And are we allowed to do this even though hydraulic balancing was carried out? (I still don’t really understand what that means.)
I also recently found a planning note from the company that installed the underfloor heating in the documentation, which says “reduced output” for the bathroom of 49W, indicating that additional heating elements would be needed. :/ However, we don’t have those. During the selection process, we decided not to include a towel radiator because we were told it wouldn’t get warm enough anyway, since the flow temperature is often below 30°C (86°F).
What we didn’t consider or know at the time was that it probably would have helped to heat the bathroom overall.

Quick note:
Look up thermal balancing.
More tomorrow.

If it’s getting too warm for you right now, you should check if your heating system offers a parallel shift option. This simply means that all settings can be adjusted up or down by, for example, 1 degree.

Is the heating system still operating at the current temperatures?

For the bathroom, you would need to check the flow rate and the supply water temperature; the same applies to the bedroom.

It might be possible to make adjustments by regulating the heating circuit distribution manifolds.

All aspects of hydraulic balancing are examined here from every angle.

https://www.hausbau-forum.de/threads/broetje-blw-neo-8-heizkurve-einstellungen.36659/

The reduced output of 49W already suggests to me that a room-specific heat load calculation was done. Can you scan and upload the data? If everything was calculated for 21°C (70°F) and you are experiencing an undersupply, that would be a challenge. However, it could also be that other heating circuits, for example the bedroom, can be throttled down, allowing more output to be directed to the bathroom.

Hydraulic balancing next winter. It won’t help now. I would also set the thermostat in the bedroom to the desired temperature if it gets too warm.

If the heating curve is lowered by shifting it parallel, there is a risk that rooms will become too cold during winter. If it feels comfortable in winter but too warm during the transition period, the heating curve is likely too flat and you will need to make it slightly steeper. How to adjust this on your THZ? It should be described in the manual.

Possibly, the bathroom could receive a bit more flow and the bedroom less. However, more information is needed for that—such as the heating circuit lengths and the current flow rate. Also, it’s important to know which rooms are adjacent to the bathroom and whether they are also heated.

T_im_Norden schrieb:

If it’s getting too warm for you at the moment, you should check if your heating system offers a parallel shift setting, which simply means that all the values are shifted up or down by, for example, 1 degree.

Is the heating still running at the current temperatures?

For the bathroom, you would need to check what the flow rate is and the supply temperature being used; same for the bedroom.

It might be possible to make adjustments by regulating the heating circuit distributors.

Shifting the entire temperature curve wouldn’t be a problem; the issue would be that it might be too cold in winter then. It’s just the transitional period that feels too warm. The heating still switches on occasionally. It was recently in summer mode, but now that the temperature here has dropped a bit, it’s on again. Here is a screenshot of the current supply temperature/settings. We only have one heating circuit; values for the second can be ignored.

We recently received a large set of planning and execution documents for storage, which also includes many details from the company that installed the underfloor heating.
For the bathroom, there are two such distribution units (it’s the only room on the upper floor). The documents indicate flow rates of 1.8 and 1.7 L/min (0.47 and 0.45 gallons per minute). For the bedroom, it’s 0.8 L/min (0.21 gallons per minute). I assume the supply temperature should be the one shown in the screenshot, if I understand correctly, considering there is only one heating circuit.

OWLer schrieb:

The reduced output of 49W suggests to me that a room-by-room heat load calculation was done. Can you scan and upload the data? If everything was calculated for 21°C (70°F) and you then have a shortfall, that could be a challenge. But it could also mean that other heating circuits, for example the bedroom, can be throttled back so more output goes to the bathroom.

Perform a hydraulic balancing next winter. It’s not worth it now. I’d also set the bedroom thermostat to the desired temperature if it’s too warm.

Thanks for the link, I will study it.
Yes, the heat load was calculated by room. The documentation states the bathroom was calculated at 24°C (75°F), the utility room at 18°C (64°F), and everything else at 20°C (68°F).
However, I don’t know how that can be achieved since we have only one set temperature at the heat pump (currently set to 20°C (68°F)).
Turning down the thermostat is not my preferred option. Several people have told me that wastes energy, but more importantly, the constant clicking noise at night bothers me.
I was also hoping we might be able to divert some heat from the bedroom to the bathroom—if that’s even possible. I’m a layperson and the system is quite complex.

Daniel-Sp schrieb:

If you lower the heating curve by applying a parallel shift, there’s a risk the rooms will be too cold in winter. If winter is comfortable but the transitional period is too warm, the heating curve is probably too flat and should be made steeper. How to do that on your control panel? That should be in the manual.
It might be possible to increase the flow to the bathroom and reduce it to the bedroom. But for that, more information is needed: length of the heating circuits and current flow rates. Also, which rooms border the bathroom and if those are heated as well.

I found out how to adjust the heating curve, but I don’t really know what to set. There are quite a few individual values that don’t mean much to me yet.
The only room adjoining the bathroom is the guest room, which is also heated—like all other rooms. All rooms except the utility room and bathroom are set to 20°C (68°F). The temperature maintained by the heat pump for 20°C (68°F) is actually closer to about 23°C (73°F) according to our thermometer. That’s fine for us; we prefer it a bit warmer.
Heating circuit length in the bathroom is 83.7 m (275 ft) and 75.3 m (247 ft). In the bedroom, it’s 107.1 m (351 ft).

If needed, I can scan some pages of the documentation once I know which ones to share, as there are very many. 😀