No flow in the underfloor heating - why can this be?

If you control a floor heating system that does not want to get quite warm, you can often find that the flow is too low at some points. Why this can be, what measures to help with fixing, and why you always have to be careful with ads, read in this post.

Display of the flow rate

The flow in the heating circuits is the most important criterion for the amount of heat that is transferred to the room via the heating system. The higher the flow, the greater the amount of heat transferred.

In addition, other values ​​also play a role in the heat transfer - but if the flow is lower than it should be, the necessary amount of heat will never be transferred to the room.

Unreliability of the ads

With the flow displays, which are usually found in the area of ​​the floor distributor, however, the display values ​​must always be a bit critical. They do not always show exactly the right values.

Due to contamination of the display instrument, the display may in some cases "get stuck" and thus not display the correct values.

In this case, you should definitely make sure of it, by putting the pump of the underfloor heating to maximum performance, and see if the ads change. If you do not do this despite the highest set pump performance, you can generally assume that the displays do not provide reliable values.

Regulate flow

Basically, you should not change a hydraulic adjustment set by a specialist himself. But if this has already been done, you should at least restore a rough hydraulic balance.

How to do that is explained in detail in this manual. In case of doubt and in very large systems, but you should better consult a professional - and in the future as possible no longer adjust yourself.

pump defects

Whether a pump is running or not, you can easily see. However, it is often difficult to tell whether the pump still provides the required power.

One way to assess this would be to turn all but one of the valves all the way down and watch the pressure in the open pipe change (and if it changes).

What is often thought to be a pump failure can also be simply air in the pipe. Air is compressible - a pump can not push an air bubble in front of it. Behind the air bubble in the line then virtually no pressure is available. On the other hand helps to bleed the plant according to manufacturer's instructions (you can also easily perform yourself in most cases).

Tips & Tricks

Regular venting is one of the important maintenance tasks that should not be neglected in underfloor heating. After venting, of course, you have to refill water in any case. How to estimate the amount of water needed to refill, can best be explained by the expert.

Video Board: Underfloor Heating Manifold Balancing