Another heating problem!!!

[t140]

I have read through relevant threads & i'm at the conclusion my system needs flushed however........

Potterton combi 80 boiler,microbore 5 rad system(3 up/2 down)...installed 5 years ago & recently serviced,guy said it was fine?????

Problem is if I put radiators on the boiler starts then switches off 20-30 seconds later.....stays off for few minutesthen on again for only 20-30 seconds.

One radiator(upstairs hall)is fine,gets nice & hot but 2 bedroom radiators are very weak...just warm.

Downstairs radiators are cold,one is slightly warm at top but cold at bottom.Also on the valve side on radiator(set to high)the pipe into radiator is cold but other side (out?) is hot.

I have bleed the system with radiator key (I only get a little air from the good one upstairs,nothing from others but water) to little effect.

Hot water is fine...very hot!

Any advice? Cant believe service engineer said it was fine(I was out at time).....its freezing

p.s. sometimes when turning hot water on I get the 'steam train noise' coming from boiler which I get rid off by opening a hot tap....air in system?

 

[Rob]

sounds like the pump tbh. unscrew the black cap on the front and pull it until it engages the impellar. should give an indication of how strong it is.

 

[t140]

Wow quick reply!!!!

Service engineer said everything was fine though.....think I have been ripped off

I'll check that after,i'm just trying it with one downstairs rad on to see if it gets hot....it is getting warmer but only at top.

 

[Rob]

it may have been working when he tried them or may have not bothered.
if the system is really only 5 yrs old and sealed from new its very unlikely to be blocked.

the combi 80s also suffer from diverter valve failure although from experience i find no rads heat up at all.

 

[corgiman]

mm sludge on the blooody wax capsule diverter valve strikes again

 

[t140]

It had a new diverter valve 2 winters ago,what gets me is boiler used to come on for along time but now only kicks in for 20-30seconds every 5 minutes or so?

However yes I must agree its probably 'sludged' up,water from rad's are black.Is it worth trying Sentinel X400 for a week?

 

[corgiman]

It had a new diverter valve 2 winters ago,what gets me is boiler used to come on for along time but now only kicks in for 20-30seconds every 5 minutes or so?

However yes I must agree its probably 'sludged' up,water from rad's are black.Is it worth trying Sentinel X400 for a week?

#


i would say its too bad for that

hire a powerflusher and get some meaty chemicals

 

[t140]

I was afraid someone would say that

Powerflush was £300 & i'd rather it was done properly,I dont mind the money
just dont want to be cold this winter......again

 

[corgiman]

thats cheap go for it

 

[t140]

Is it a big job,takes long? makes alot of mess?

 

[corgiman]

a big job maybe depends on extent of sludge, messy nah not if done right and with care

 

[t140]

ok cheers for that & to everyone for their help & time,

Thanks,Ian