Combi Boiler Not working

[aka123]

My boiler is a Worcester Combi 28CDi RSF. I drained the system to remove two radiators (one permanently) but it will not refill. The pressure gauge is showing zero and although I have let if fill for some time the gauge is not moving. Every now and then as it is filling, there is a loud clanking sound which I assume is coming from the pressure relief valve as water is coming out of it (pipe in garden) at the same time. According to the info I have, the system pressure should be 1 bar and the pressure relief valve should actuate at 3 bar. Its starting to get cold so any advise would be greatly appreciated.

Thanks Steve

 

[mickyg]

the pressure gauge is probably blocked and sticking, your probably filling over 3 bar and the clanking is the prv opening.

 

[aka123]

Hi Mickyg. The guage was working fine when the boiler was running this morning and I have tapped it several times but there is no movement. Can you recommend a course of action.

Thanks Steve

 

[mickyg]

yep, drain it, and where the gauge capillary tube connects into the system, disconnect it and check for blockages.

 

[aka123]

Thanks again. I have tapped the tube several times but it did not do anything (I am a bit uneazy disconnecting bits). I have water coming out of the upstairs rads via the bleed point so assume that I have water in the system. Would it be OK to run the system with an unknown pressure ?

Steve

 

[mickyg]

Would it be OK to run the system with an unknown pressure ?

Steve

yeh should be fine. If it sounds gurgly after 30mins or so with bleeding add a bit more. If it starts clunking again, take some away

 

[bengasman]

only one reason why this happened, corrosion.
search the forum what to do about it before you get huge bills

 

[aka123]

I have started the boiler and all rads are warming-up. The pressure gauge has moved very very slightly. Bengasman, can I ask what you mean by corosion being the probleum ?

Thanks
Steve

 

[bengasman]

when a system is poorly installed or poorly maintained, corrosion starts and the residue caused clogs up the system slowly but steadily resulting in blocked heatexchangers, pipes, radiators and dying pumps

 

[Agile]

when a system is poorly installed or poorly maintained, corrosion starts and the residue caused clogs up the system slowly but steadily resulting in blocked heatexchangers, pipes, radiators and dying pumps

And not in the least....

pressure gauges!

 

[bengasman]

true, but you don't really need a pressure gauge; check that the expansion vessel works properly, heat the system up to max, and stop filling up just before the prv starts letting out, and turn the boiler stat back to 80% or less and keep it there

 

[powermaxer]

one job leads to another.
you can probaly unblock the inlet (drain boiler first) end by removing a push fit clip and pick out debris from capilary tube end with a safety pin or where capilary tube fits into.
if all clear buy a new guage.

 

[Agile]

true, but you don't really need a pressure gauge; check that the expansion vessel works properly, heat the system up to max, and stop filling up just before the prv starts letting out, and turn the boiler stat back to 80% or less and keep it there

I have a work around for a blocked gauge too but its a less closely guarded trade secret!

Tony