Radiator advice

AddicksAddict

We've got a radiator that's behaving strangely so I'd appreciate it if anyone can suggest a solution.

The radiator is hot at the top but there's no heat along the bottom for most of the length.  If it needed bleeding, I'd expect it to be hot at the bottom and cold at the top.  So, any suggestions, anybody, as to what is wrong and what can be done to sort it.  Thanks in advance for any assistance.

Dave Rudd

Where is the inlet and the outlet?  Both at the bottom?

Are either of the pipes leading into the radiator hot?

I'd bleed it anyway.  If there is a significant temperature difference across the radiator, there is clearly little flow.

DaveMehmet

Sounds like it’s silted up. You’ll probably need to flush rather than bleed it. Not as difficult as it sounds, Turn off heating, disconnect and drain the rad, take it off the wall, take outside and flush it through with an hosepipe.

Will make a mess so protect your carpet/flooring.

eastterrace6168

Sounds like sludge build up in the rad, and will need a flush, so you need to get a heating engineer involved, no easy fix apparently sorry..or get @DaveMehmet round ...

Dave Rudd

I'd definitely try bleeding it first (as that will take a few minutes) before taking it off the wall and trying to flush it.

It may well need flushing, but a bleed is quick and easy.

jonseventyfive

Sounds like an air lock, take cap off and bleed the system. 

AddicksAddict

Dave Rudd said:

Where is the inlet and the outlet?  Both at the bottom?

Are either of the pipes leading into the radiator hot?

I'd bleed it anyway.  If there is a significant temperature difference across the radiator, there is clearly little flow.

Both pipes are at the bottom.  One pipe is very hot, the other cool if not cold.  Bleeding did nothing so it sounds like it needs flushing.

AddicksAddict

Thanks everyone who commented.  It sounds like we have the solution.

Chippycafc

May i ask are the pipes microbore or are they 15mm. If you have a drain point it maybe worth draining the radiator and part of the system and topping up the header tank (if you have one) and topping it up with fernox.

Alternately you could get a company in and give the whole system a power flush but you are likely to have to sign a waiver as this could effect any other weakness in your whole system

AddicksAddict

Thanks, @Chippycafc.  Everything is about five - seven years old so I don't think anything will be microbore.

Rob7Lee

It's silt/scale at the bottom. It's likely your whole system needs a flush through as unusual to all collect in one radiator, although could be the valve is almost closed on that one holding it all up.

Probably needs some additive as well to break it down if you don't go for a power flush. Sentinel X400, run it for a few days (or even a week or two if really bad) then drain down and refill and add in an inhibitor (X100).

If you have a header tank it's easy, if not you may need a plumber to help although you can fill through the top of the radiator if you turn it off and drain a bit out.

Just doing the one radiator probably won't fix it all together.

If your water is very hard consider an Aquabion, not cheap but very effective.

Raith_C_Chattonell

Worth remembering if you have a 'sealed system' combi boiler (with no header tank) that the pressure will drop when you bleed a radiator. 

Bleeding in this case is best done cold - then check the pressure meter reading on the boiler - which will almost certainly need refilling.  Youtube is your friend here.