Help please. Central heating system from Hell

[doitall]

Could still be sludge or an air lock.

What type of system and size of pipes.

 

[teessidemark1]

22mm , and its a suprima 40.

 

[teessidemark1]

the pump has had the air bled out , so no air lock in pump

 

[jackthom]

With the hot water turned off and with demand for central heating only, check by feeling the pipes that the hot flow from the boiler is being directed by the valve towards the radiators and is not also flowing towards the storage tank.

That should at least eliminate the valve although of course it could still be partially sludged up along with other parts of the system.

 

[doitall]

22mm , and its a suprima 40.

I was thinking more the size that feed the rads.

 

[teessidemark1]

thanks, what ive found is as soon as you explain the problem , no heat in rads , most heating engineers have just presumed faulty pump , or power flush and when ive explained the new parts installed , many not too fussed about the job!!

 

[teessidemark1]

sorry mate , wouldn't have a clue , I wouldn't like to guess. its a standard installation ,

 

[kbdiy]

Forgot to add. In August. I drained down all the rads , by adding a hose pipe to the bottom rad in the kitchen and then , going in loft and tying up ballcock so it went empty

opened up all valves upstairs and water came out no sludge.

But did you take each rad off and flush it through? The fact that it drained from one rad doesn't necessarily indicate that all the rads drained completely and removed any sludge. If the upstairs rads work ok as you suggest then I can't see how it would be the 3-way, but that's just me trying to take a logical approach to the problem. Sounds to me like the water can't circulate round the downstairs circuit which for me points to some kind of restriction.

 

[teessidemark1]

again "a little bit of knowledge"

I was told if it was sludge , the water would be black , it was clear like mountain spring. Didn't take off the rads one by one as was advised this way was easier way of clearing sludge

 

[doitall]

I would take all the lower rads off then connect a hose to each valve and run about a bucket of water from each valve (flow and return)

 

[Whitespirit66]

, resulting in the rads upstairs hot and the downstairs cold?

Back to basics - what happens when you turn off all the working rads upstairs and turn on the heating?

 

[teessidemark1]

if I turn upstairs off and then turn on the downstairs , the downstairs works fine

 

[Whitespirit66]

Could well be just balancing. No problem with blockages or valves if all rads work, albeit half at a time.

Number 5 on here -

http://www.diynot.com/forums/plumbing/boiler-central-heating-faqs.175736/

 

[Whitespirit66]

Or watch this -

 

[teessidemark1]

I rebalanced in August , and it worked. However as soon as you turn off the heat demand your back to square 1 and it wont work.

it tends but not always if the heatings on for a few hours , eventually but not always you get some heat In the downstairs rads