DRAINING SYSTEM DOWN - WORCESTER 28 cdi

[BRIGHTHOPE]

I've had to drain down my system today to sort out a problem valve. It runs on a Worcester 28 cdi combi boiler.
All I've done is drain out the water from the central heating, and filled it up again, but the boiler's playing up now. Is there something I should do with the boiler before starting up again. The pressure is back up where it belongs, but when the boiler fires up, whether it be for heating or hot water, it stays on for maybe half a minute, the goes out.

 

[bengasman]

Probably airlock in the boiler. Is there wooshing noise like air in the pipes?

 

[kevplumb]

check auto air vent top left

make sure the cap is loose

 

[BRIGHTHOPE]

There is a horrible gurgling sound just before the boiler cuts out when the hot water is on. If it's an air block in the boiler how
can I get rid of it??

 

[bengasman]

There is a horrible gurgling sound just before the boiler cuts out when the hot water is on. If it's an air block in the boiler how
can I get rid of it??

check auto air vent top left

make sure the cap is loose

And/or bleed the pump, and check it spins.
See FAQ

 

[kevplumb]

View media item 667

 

[BRIGHTHOPE]

Bled the motor, but little or no air came out. Located what looked like a tyre valve cap on the top of the boiler casing. When I turned it anticlockwise I could hear air being released. I take it that air shouldn't build up like that and that it should remain open all the time? Strange though, because it's not been touched for years.

 

[BRIGHTHOPE]

Boiler seems to be working fine for now, must have been that release valve at the top of the boiler casing. Just to clarify, that should be open all the time should it? and there shouldn't be any build up of pressure, just a constant steady release through it?

By the way....thanks for your help chaps.

 

[bengasman]

I take it that air shouldn't build up like that and that it should remain open all the time? Strange though, because it's not been touched for years.

Air should not build up.
Cap should always be open.
Chap that serviced the boiler should have checked this.