ᐅ Settings for the underfloor heating when it is not working

Good morning,
as every year at the start of the heating season, our underfloor heating is not warming up. However, the gas boiler is working properly since hot water comes out of the tap without any issues.

Can someone tell me what I need to adjust on the manifold so that the heat flows through the floor again?

Thanks!

The manifolds are all open, so the issue must be elsewhere.

What heating limit is set?

How warm is it currently inside the house?

Is there pressure in the system?

What have you been doing in previous years?

I suspect that the heating curve might be incorrect, or the parallel shift is off, which could cause the house not to warm up properly during the transition period.

When you say every year, what exactly has been the problem in previous years?

Is the heating function activated on the gas boiler?

The actuators for the underfloor heating are all open in your picture. Is heat coming from the heating system? The pipe with the red shut-off valve should feel noticeably warm when it’s cold outside. If that’s not the case, it’s likely that no heat is coming from the boiler.

I experienced something similar last winter. There was a defective valve on the heating system.

If it’s not an issue with the pressure or heating curve, I would suspect the 3-way motorized valve that switches between domestic hot water and heating. Google it to see what it looks like. The white actuator should be positioned at the top for heating mode.

You can easily test whether your underfloor heating is working by using an infrared thermostat to measure the supply temperature at the pipe. (Each individual pipe in every circuit should show the same value – measurement errors usually stem from the method used.) This supply temperature should correspond to the set value according to the heating curve. Measurements should be taken while the system is in heating mode.

What exactly is not getting "warm"? The room or the floor itself?

vibias schrieb:

As every year at the start of the heating season, our underfloor heating is not warming up.

… because at the start of the heating season, the outdoor sensor doesn’t receive enough input.

vibias schrieb:

Can someone tell me what I need to adjust on the manifold so that the heat flows through the floor again?

Set it higher so it reacts earlier. But I’ve heard that due to the 2022 energy crisis, it’s better to wait a few degrees until the heating turns on by itself at point x 😉