Powermax 155 - Some cold radiators ... Help!

[BigColy]

Two of my downstairs radiators are cold. The inlet pipes are also cold. wierd thing is that they are at different ends of the house (one living room, other dining room).
I have disconnected both radiators and flushed them through. I have also replaced all valves on both, drained the system, refilled and bled, but the problem still exists. All other radiators are piping hot - no problems.
Does anyone have any idea what could be wrong?
The house / system is eight years old.

 

[jamsco]

hi, big coly, this could be a possible air lock, i've encountered this on many jobs. get the heating up to temp and open the valves on the cold rads, then shut off the other rads (the hot ones), this will hope fully get them going. open all the rads back up once the 2 problem ones are warm and bleed them all. also check for and air vent in roof spaces and vent these. good luck.

 

[jamsco]

ps if is helpsthat fails yr pumps probably shot, thus it can't pump as far as it once could. hope th

 

[jamsco]

sorry that should've read, ps if that fails yr pumps probably shot, thus it can't pump as far as it once could. hope this helps

 

[BigColy]

Hi jamsco - really appreciate your prompt reply.

Tried option one (shut all but the cold rads down, etc.) with no luck on a result. Seems the pump might be the problem, then.

Any idea where I can get one of these and roughly how much it will cost me? Do I need to get a fitter in to do the work or is it straight forward enough? I do have an iso valve on each side of the pump.

 

[Vic Spanner]

Hi jamsco - really appreciate your prompt reply.

Tried option one (shut all but the cold rads down, etc.) with no luck on a result. Seems the pump might be the problem, then.

Any idea where I can get one of these and roughly how much it will cost me? Do I need to get a fitter in to do the work or is it straight forward enough? I do have an iso valve on each side of the pump.

Order new pump from parts center or off the web..Dont touch the valves they will leak just drain it down or just change the head.

 

[sooey]

Whatever you do, don't get one of these

http://www.dailymail.co.uk/pages/live/femail/article.html?in_article_id=510021&in_page_id=1879