Boiler help needed asap

heatherw_01

This morning the boiler pressure was below the recomended level, but this afternoon it is nearly 4!!

How can I reduce it?

It is a Worchester Bosch ZWB 7-27 HE

ariba10

The question is how is it over pressure?

If it is because you over filled it, you can shut the boiler off and when the water is cool enough you can drain some off through a drain off valve.

If the system pressure gets too high there is a safety valve that will blow off to the outside.

weekendwarrior

This seems to be quite common.

Here is how to Pressurise a combi

The thing you have to watch for is the filling loop, yours may be passing.

This means that it is not closing fully and so the mains water pressure is forcing the pressure up in the boiler.

You can also release some pressure by Bleeding a radiator, Use on old rag to soak up any water.

You can check that the filling loop is not passing by disconnecting it from the boiler.

heatherw_01

I filled it a little this morning as the pressure was low and the pressure rose in the afternoon.

I don't know where to drain it, can I just drain it a little via the bleed value on the radiators?

ariba10

heatherw_01 wrote:

I filled it a little this morning as the pressure was low and the pressure rose in the afternoon.

I don't know where to drain it, can I just drain it a little via the bleed value on the radiators?

Yes you can, but it will take longer.

A thing to remember, the pressure is higher when the water is warm than when it is cold.

heatherw_01

I will have a go at that when it is cold. Hopefully it will drop