Central Heating system - advice please

ViksB

We have a central heating system which works well, it heats all the rooms bar 1 well. The one it doesn't seem to heat is the dining room. The top of the radiator gets warm, bottom stays cold whilst the others are hot.
We have tried, turning all the other radiators off.
We have turned the "broken" radiator on and then off a few times.
We have bleed the radiator - no air -it does seem to collect air, but after being bleed it doesn't heat up fully, the air takes a couple of weeks to return.
We have yesterday taken the radiator off completely and rinsed it out, as I was convinced it was full of sludge. It did have some sludge in it, but not alot.
Despite trying all that, the radiator still only gets slightly warm at the top. Any further ideas on what I could try.
The radiator isn't last on the system. There are a mixture of sized pipes for the radiators, the newer ones have the normal sized pipes, but the others (inc this one) have that flexible copper pipe that is only about 1cm in diameter.
Would love some advice otherwise this winter, it will be back to the gas cylinder heater in that room!
Thanks
Viks

EliteHeat

It sounds like your microbore pipework is almost completely blocked.

If you have some circulation, it is possible that a power-flush may remove the blockage, unlikely but possible.

The most effective solution will be to cut out and replace the copper, preferably with proper 15mm.

ViksB

Thanks Elite Heat,
How do you do a power flush?
Viks

Canucklehead

Hi
When you had the rad off did you try opening up the valves into a bucket at both ends?

Was this rad fitted as an addition at some time? I have known rads to be cut in but both flow and return have been teed into the same pipe.(actually it was me!)

Corgi Guy.

EliteHeat

ViksB wrote: »

Thanks Elite Heat,
How do you do a power flush?
Viks

Well, you can hire a power flushing machine for about £50 from HSS or similar, but I wouldn't recommend it. You can do a huge amount of damage to your carpets and ceilings if you get it wrong or connect it incorrectly.

It would be a good idea to try the previous posts suggestion and remove the radiator and then open each valve in turn into a bucket. If you have an obviously restricted flow from either end, then there is your problem.

From your symptoms and from your fault diagnosis, it is almost a certainty that this is exactly what you will find.

ViksB

Do you mean remove radiator obviously with closed valves and then turn on valves with the radiator system pumping?
What sort of flow rate should we be expecting?
Will try to encourage hubbie to help me remove the radiator (again!!)

Viks

Canucklehead

Hi

Yes , remove rad with valves off, system should be off, flow rate will vary but if you do one then the other you would expect then to be of a similar rate.Make sure all the other rad valves are open.
You might find that a section of pipe can be replaced from a manifold to the valve or a kink in a pipe under the floor.
Good luck!!

Corgi Guy.

keyboard

Hi ViksB

I have had more or less the same problem with regards to one rad not heating up. here is the link to my post and advice I was given.

http://forums.moneysavingexpert.com/showthread.html?t=519034&highlight=keyboard

I have not tried doing the powerflush yet due to lack of time, but hope to soon. Will eb interesting to know if it works for you.

Cheers

Good luck