central heating not working after new radiators fitted

[pinkllama]

hi all,

i have just replaced 2 radiators with larger ones in my flat as it took hours to heat the flat up.

it's an open system, ie there is a header tank in the loft.

i refilled the system and bled all the radiators.

the problem now is that the boiler fires up for a few minutes and then switches off - not heating any of the radiators. i've put the thermostat on max. the header tank has water in it.

prior to fitting the new radiators, it worked fine.

i understand that the boiler is switching itself off as a safety measure as it is too hot.

i think that there could be an air lock in the boiler that is preventing it from working/ pumping the water around the radiators. when i turn the boiler on, it sounds 'hollow' as if there is no water in it.

its currently -5c outside and i desperately need some help!!

are there any other places, apart from the radiators that should be bled of air?

regarding bleeding the pump, i took the chrome nut off the front when the system had been refilled, but couldn't see how to bleed it. there is a large plastic turnable slit on the right hand side, is this where you bleed it?

one thing that could be a clue as to why it's not working is, when i refilled the system the header tank let loads of water in for a few seconds then it just trickled in for the next hour or so before all the radiators were full of water.


any advice?

thanks

 

[Winston]

Sound like a air lock, you may have not filled up completley try again or worse scenario try filling up with mains pressure via the drain off, but be careful. You dont want water going over the feed and exspanion tank.

It is also common when new rads are fitted that they dont heat up, if this is the case turn all the rads off via the trv with the boiler on and open the new rad up with the trv and wait for it to heat up, then go round and turn the others back on.

 

[Sanke]

When refilling a system i now always follow the same procedure as Winston has described This saves a lot of time & stress

 

[pinkllama]

Sound like a air lock, you may have not filled up completley try again or worse scenario try filling up with mains pressure via the drain off, but be careful. You dont want water going over the feed and exspanion tank.

It is also common when new rads are fitted that they dont heat up, if this is the case turn all the rads off via the trv with the boiler on and open the new rad up with the trv and wait for it to heat up, then go round and turn the others back on.

thanks - 2 of the rads are now working (the ones i didn't replace)
l'll turn those off and see if any heat gets to the others.

is it a good idea to bleed the 2 rads that aren't working, of some water. hoping that air will eventually come out?

 

[Winston]

Hi Pinkllama did you get them all working ok

 

[pinkllama]

all sorted.

got a plumber round in the end.

glad i had a go first. learnt quite alot

thanks for all the advice

 

[Winston]

Sorry if we couldnt have helped, but glad you have got it sorted.

 

[REDSAW]

OF COURSE, you have to share the fix with the rest of us for reference.lol