Bottom of radiator not heating up

[evets51]

I had a new boiler installed approx a month ago, this included a powerflush which I'm satisfied was done well as previously the water coming from the vent keys when I had an airlock was filthy black - the 2 airlocks I've had since it was installed the water is clear.

We noticed one bedroom didn't feel all that warm - I felt the radiator and it was hot. However it was only last week that I thought to feel the bottom of the radiator - its cold, only the top is hot. Previously this room was very warm so I think the bottom being cold is since the new boiler was installed.

From what I've read this is sludge in the bottom of the radiator. I've tried to contact the person who installed the boiler to come look at this but he's hard to get hold of - pretty busy I think and doesn't return calls. Overall I'm happy with the work he did.

Question is - in expert's opinions is this likely to be something that was "caused" by the installation, and therefore should I be pushing to get it rectified for no further charge? If not, then I'm happy to call another engineer and ask him to fix it - but something at the back of my mind says the room was warm before the new boiler was installed and now it isn't, therefore its a problem with the install ...

Thanks in advance

[folwlerg68]

could be quite an old radiator so even though you had the system power flushed the corrosion was already quite advanced. or have you tunred the locksheild valves down and not opened them fully ?sometimes the plastic head is not actually moving the spindle you need to take of and check with a spanner or t.r.v. might not be opened fully.

[steveb]

yes it does sound like sludge to me. is it only on one radiator that you have a cold spot? easiest way to sort this is to take the radiator off and take it into the garden and flush it through with a hose. i think that the flush wasn't as thorough as it could have been imho how long did the installer take on it?

[glenno1]

are both pipes getting hot at the valve

[warrington]

If your system power flushed and system is clean.I suggest your radiators needs balancing. Turn of all radiators except one you having problem, once you have satisfied heat start to balance the other ones one by one.

[mountainman]

Bit worrying that your installer is hard to contact.
He may have done a good job but after sales service is equally important in my book.
Maybe I'm old fashioned!

[steveb]

even if i was rushed off my feet i would return a call it may be for more work after all.

[SimonG]

even if i was rushed off my feet i would return a call it may be for more work after all.

Snap, but maybe the bloke knows there's a problem

[steveb]

there's always that

[Mike Jackson]

If your system power flushed and system is clean.I suggest your radiators needs balancing. Turn of all radiators except one you having problem, once you have satisfied heat start to balance the other ones one by one.

That sounds about right to me. If the rad is still cold at the bottom with all the others off then it's sludge, if it gets hot it's a balancing issue.

[evets51]

Bit worrying that your installer is hard to contact.
He may have done a good job but after sales service is equally important in my book.
Maybe I'm old fashioned!

Well yes that's a separate issue really - and why I'd prefer to go somewhere else to get this sorted unless its a direct result of the install.

So - yes both pipes are hot, the inlet significantly hotter than the outlet. I've checked the TRV and it is fully depressing / releasing the nipple inside. And yes, even with other radiators turned off it still doesn't heat up at the bottom. That's one of the first things I tried as having done a bit of research, I was concerned at the power of the boiler that was put in - its an 18 kw which was sized purely based on it being the same (actually about 1kw more powerful) than the one it was replacing. The old one was 20 years old and was installed when this was a 4 bedroom house. The previous owners have installed a 5th double bedroom over the garage (1 large radiator, 1 small in walk in wardrobe) and 1 heated towel rail, plus a conservatory with 2 radiators. So I thought maybe the boiler wasn't powerful enough - but turning the rest off didn't help, and the rads do seem to heat up quickly enough so I don't think that's it.

[mountainman]

Sorry but I disagree that it's a separate issue.
Power flush and boiler change is The full monty.
If the problem is really due to sludge in that particular rad then the PF wasn't effective so get the installer back.