power flush, chemical flush or something else...?

oochiepoochie

hello, apologies for another PF thread- i've had a look at some past threads but i'm still stuck on where to go from here...

i had a new combi fitted just over 7 years ago- i can't find the paperwork but iirc a powerflush was done on the system beforehand. neither the radiators or the pipes leading to them were replaced. i haven't been adding inhibitor to the system as i only recently found out about it (always lived in rented accommodation until then- never had to deal with that sort of stuff- my bad).

there have been two occasions where i've had to top-up the boiler: first, shortly after the system was installed and more recently when the expansion vessel went flat and the pressure release valve repeatedly spilled its guts over my kitchen window over the course of a week. i'm guessing that the original inhibitor is now long gone.

anyway, all the radiators in the house get hot, with the exception of the one in my bedroom which is freezing at the bottom and barely lukewarm at the top. i've no idea how old it is but i'm wondering if this is a sludge problem. i'm not sure if this is relevant, but the pipe coming into the radiator is hot when the CH is on, whereas the one coming out (which has a thermo valve on it,switched to max) is not.

i've spoken to a local gas plumbing firm who have suggested a powerflush at the cost of £420.00 but as there's only one radiator that's a problem i also asked for a price for fitting a new, sludge-free radiator (which i would source- priced at about £50.00) and then a chemical flush. this would be £220.00 but came with the warning that not all the sludge would be removed and that they would strongly advise against it.

i've heard a lot of negative stuff about powerflushes and now i'm not sure how to proceed. does anyone have any opinions and/or knowledge that can help me decide if it's worth spending the extra £150.00?

many thanks

Knill

Is it a large or small radiator?

You could probably give it a bit of a flush with a hose pipe by yourself firstly just to see if that helps it in anyway.

Lgas

Try this first - turn all of the radiators off apart from that one, and see if it heats. Then turn back on. Sometimes that's all it needs if you're lucky, otherwise get someone who knows how to balance the system properly to have a go at that before considering the powerflush.

southcoastrgi

I'm going with a faulty/stuck trv

Alias_Omega

Stuck TRV

Look here - http://www.youtube.com/watch?v=phFW-IIsH54

Remove Sludge

Look here - http://www.youtube.com/watch?v=Ru-nNFqBzqk

oochiepoochie

hi, thanks for your replies

the radiator is quite big- 500mm x 1800mm so i can't take it off myself. a friend whose husband works in a plumb centre has passed on the number of an independent plumber though who'll take it off and flush it through for £40 or indeed fit a new rad for the same price so that's one to consider.

interesting about the trv: there was an incident a few years ago when it came off the radiator (don't ask, i have no idea either!) and my ex 'fixed' it back on by whacking it with a hammer :T thinking about it, it hasn't been right since (i know- shock, right?)

great links on youtube- i didn't know there was stuff like that on there. i'm going to have a fiddle around with and see what happens.

powerflush definitely on the backburner for now, though i'm certainly going to see about a chemical flush and getting some new inhibitor in in the next couple of months.

thanks for taking the time to reply

Lgas

Didn't realise there was a TRV, er yeah, that doesn't sound good!

oochiepoochie

Well, the little pin on the trv was moving freely in and out so looks like that wasn't the problem. I've turned the other rads off and opened the lockshield fully and now the lukewarm bit is slightly more lukewarm but otherwise no change. Rats.
Time to call in the plumber to get the rad off the wall for further poking about-hope this isn't going to be too painful on the purse...

Thanks again

JohnB47

A bit obvious, but you have made sure that the valve on the other side is open?

oochiepoochie

Hi,yeah the lockshield is fully open. Urgh, I was hoping for an easy fix :-(

Lorian

I presume you have bled any air out of the radiator?