Vent hot water circulation pump

When the circulation of the hot water system no longer works properly, air is often the problem. System or pump ventilation is not always successful straight away. Here are a few ideas where it can catch and how you can get rid of the air.

Problems venting the hot water circulation?

Problems with hot water circulation are often caused by air in the system, which can enter the circulation line, for example, when working on fittings, when replacing components in the storage tank or when piping repairs. As a result, not only does the hot water no longer arrive at the draw-off points comfortably quickly and there is no sufficient movement against germs. The circulation pump can also overheat and damage the bearings.

To get rid of the air and problems with circulation, it is necessary to take the following measures:

  • Coarse ventilation via tap fitting
  • Ventilation via circulation pump

First of all, the coarsest amount of air must be let out of the system by opening a tap. Here the water is allowed to run until the jet is clean and splash-free.

But that is not enough. The circulation pump must also be vented. This can be done simply by loosening the screw connection. Pumps with a spherical motor have a vent flange for venting.

However, since the non-return valve on the circulation pump stops the circulation during the first venting process and the flow rate is rather low in a well-balanced circulation line, air residues can still collect in the line windings and in the fittings. These can then gradually accumulate in the pump and in turn lead to disturbances in the circulation and to the pump running dry.

Are the ventilation requirements given??

For a successful, complete venting process, it is of course important that the venting devices can also perform their function correctly. If, for example, a non-return valve is stuck on the pump, the venting may not work properly either. So you should always look separately after this valve, clean or replace it if necessary.

Every now and then there is a mess when installing the circulation pump. If the installation location is unfavorable, for example above the storage tank and perhaps even in a horizontal pipe section, trapped air may not be able to escape properly. In that case the pump would need to be relocated.