How do you vent a CH Pump ?

[self builder 123]

Hi

In our CH system we have a system boiler plus 2 underfloor heating manifolds.

The is a circulating pump on the boiler together with a circulating pump on each of the manifolds.

When the CH is running there is a slight noise coming from each of the pumps which I assume is trapped air ?

To vent this air should I simply remove the vent plug at each of the pumps, when the CH system is running, to let the air escape ?

Cheers

 

[jimyboy]

hi
you do open the vent plugs but don't have the heating running

 

[corgiman]

if you want to vent the pump it will have either a silver cap with a slot to undo or a nut

 

[self builder 123]

Gents

Many thanks for your replies.

So is it a simple matter of turning the CH system off when venting the pumps ?

The reason I ask is that the Grundfos manual suggests setting the pump to Position 3 with the pump running and then opening the vent to let any trapped air escape ?

 

[corgiman]

I always find it best to vent a system when it has been left off over night, gives the air a chance to rise