worcester boiler - not working after fitting new radiator

There is probably an air vent on the boiler, have you bled that? I may be mistaken but it sounds like the pump is trying to pump air. Did you drain the system to fit the new rad?

No I didn't drain it. I had already fitted a couple of isolator valves some months back isolating the new part of the system. Your diagnosis makes sense -I think you must be right. I can't see a bleed valve on the outside of the boiler. I'll take the cover off and see if there's a bleed valve for the pump or somewhere obvious.

thanks

tony

I cant see anything that looks like a bleed valve inside the boiler or near the pump. There's something that looks like a bleed nipple, with a rubber cover on it, just below the pump. The pump is side on and the ends are inaccessible.

Here's what it says about that symbol on the Bosch website:

-Quote- What does this symbol mean: "-//-" ? This is the siphon fill programme. When switching mains power on to the boiler it will fire at a minimum output for up to 20 minutes. The central heating function will be run at a minimum output during this programme.

-unquote-

What is a siphon fill programme? Does that mean it's ok to leave it running and it'll sort itself out after 20 minutes?

It's something to do with filling the condensate trap.

Ours does that if it's been off. Yes - let it run for 20 mins then it should fire up normally.

Bloody annoying after a power cut on a cold morning....

I could be a mile off but I had something similar happen. In my case there was a valve at the very top of the boiler on a tank/cylinder sort of thing which needed the air letting out of it.

Good luck anyway.

Matt Thanks that worked. So what an unnecessary worry that was!. Part of the design. Guarantee still safe.

RDS We had similar on our previous (Ravenheat) boiler, but maybe the new one does all this programatically - I can't see any equivalent. Nev'theless all;s ok now.

Cheers Tony

I know the problem is solved buy another possibility was that some debris from the new rad or pipes got swept into the system and jammed the pump. THis happened to me when I failed to flush properly after adding a new rad to the system.