Rads cold

[sparky]

Hi all,

Got a problem where only a couple of rads getting hot in bungalow.
Originally it was the bed rad stone cold. Drained and flushed the system with fernox F5 and changed rad valves now that rad gets hot and bathroom but others cold? Combi boiler, loads of pressure at rads but heat not reaching them. Could this be a knankered pump? System is clean. Thanks in adavance.

 

[tony the plumbe]

hi you say you flushed the system but did you use a power flushing macheen?

 

[sparky]

hi tony, no but the system water was fairly clean abit black at the bottom of the rads thats all.

 

[Billy Bob Bob]

what make combi

 

[FD Powerflow]

As per the above comments what is the boiler and make of pump, also is it a minibore system with manifolds? Ive had one or two where the system was fed via the good old yorky spider manifolds (22mm down to 4x 8mm) and when ive introduced a cleaner to the system it seems to block up the head of the manifold. Worth checking them to see if they are getting warm or if sludge has blocked them.

Ive got a TF1 with Polyplumb tap connector valves and what I do is cut a section of return stick it in overnight, if when I come back its full of magnetite you know it could benefit with either a powerflush or a filter being fitted. If it comes back clear I just stick two endex slip couplings back over the pipe I cut out and re solder. Costs me a couple of quid on the jobs where it doesnt need it but to be honest they are few and far between.

If it needs a powerflush then Id highly recommend borrowing a double magnaclean, theyre great for connecting up with your machine and at the end of it you wont believe how much sludge will be on the magnets.

 

[sparky]

Thanks for the replies. its a halstead boiler not sure of model but all rads fed with 15mm copper, 22mm in loft.