pipework blockage

[daniel1964]

New boiler, all new radiators, pump fine, flushed system multiple times with cleaner ( over the last 2 years) and water comes out clean. The cleaner has been in the system for a week at a time and chucked out lots of sludge the first time and nothing since . Radiators upstairs nice and hot. Downstairs not!!! Just lukewarm or one is mostly cold. Tried turning off the upstairs rads and only having one rad open at a time, downstairs. No joy.
Power flush seems like a waste of time and money. Any suggestions. Dont want to have floorboards taken up but if it has to be done then so be it. (had new carpets fitted last year!!). Is there any fairly straight forward way that the pipes can be flushed individually to locate the blockage? By a qualified plumber , not by me.

 

[PlumbBobBob]

possibly pump goosed

 

[daniel1964]

What sort of amount are we looking at . Also I live in north west london. what does goosed pump mean?

 

[dontknowitall]

Pump failed is what Steve means - unless he's talking about his duck pond again...

Around £125 when you're outside London.

 

[Al7]

Still got old existing pipework? Could it be anti-gravity valve?

 

[jase158]

Problem with cleaning system out is that if there is a blockage, if there is no flow at all, there is no way for water and chemicals to clean system out. besides looking for non return valve, anti gravity valves i.e. which are blocked, chances are that you will need to completely replace downstairs pipe work.

I have just re read this and you have all radiators slightly warm, so you are getting flow. would reccomend power flush or as below, try doing manually but with 2 x chemicals and banging radiators

 

[jase158]

Just out of curiosity, did you bang radiators and pipework when doing flush? try doing again, with 2 litres of chemicals rather then the 1 reccomended or 4 instead of 2. when it has been in for couple hours with system running, use rubber mallet to hit radiators a few times and pipe work, switch boiler on a few times whilst doing it, see if radiators improve.

Sounds like you have got surface rust out but not the hard stuff, this is the stuff that settles in the summer months. although there shouldn't be too much if you have just had it all replaced.

other option is boiler isn't large enough for system. Has system ever worked?

 

[marleyco]

Fit a system filter like f1 or magna clean for good measure. At least there will be some where for dirt to be collected. I swear by them

 

[Best]

Why not get one of the downstairs rads taken off if you suspect blockage, turn all downstairs rads off so that flows & returns can't mix & then connect each of the 2 rad valves, one at a time to a hose & open them to see if main pipes blocked or not? Circulating pumps sometimes only heat a few rads properly & stop heating the harder ones to circulate to. Worth taking pump off & if it's not scaled up then changing it.

 

[stevetheplumber]

had similar on a job once and it was a tee where the center pipe had gone in past the stop and was blocking the flow of water