cenral heating/Radiators

Our central heating radiators on the ground floor have one by one stopped getting hot. They have all been taken off the wall and been flushed out with water, but this hasn't made any difference. We have mircobore copper piping, we also have a combi boiler. The Radiators upstairs always get hot. The central heating system is about

30 years old. The combi boiler is about 10/11 years old. Does anybody have any idea what the problem is, and how we can resolve it.
Reply to
ab
Loading thread data ...

Does the system have a header tank, maybe in the loft or above the boiler, and is it filling properly?

If no to the first question, then how is the water replenished in the system?

After you are re-connecting the radiators, are you bleeding all the air out the system properly?

If the answer to question two is a fill loop from the mains water supply, then are you topping the system up to its full pressure after you have bled the air from each radiator?

Does the boiler activate properly when you demand hot water?

I could go on asking questions, but these questions need an answer first, before we can give any type of advice on what could be wrong. And I'm sure others will be along with more questions once you have answered these ones.

Please give more info' on this please. Thanks.

Reply to
BigWallop

Tired pump? Sludge? Scaled up microbore? Airlock?

You say they've stopped over time. How long are you talking about? A week? A year? Have you tried turning off all of the upstairs rads? What happens if you do? My next step would be to flush the system rather than the individual radiators, maybe with some cleaning chemical. See what comes out. If flushing doesn't work I'd reluctantly replace the pump I guess. The age of the system shouldn't make too much difference in this respect other than as an indicator that things might be wearing out. That said the only thing I can think of which might cause this problem because of wear would be the pump.

Good luck.

Reply to
Calvin

Thanks for responding

We don't have a header tank

The water is replenished in the combo

All the air has been bled out of radiators

We get hot water, no problem.

A friend has called us tonight and suggested a power flush and it will cost £300 to £400

Reply to
ab

First it was the hall, just over a year ago, then the Dining room about a year ago, but now the two in the living room are just warm, the kitchen radiator remains hot. We are going to try a power flush, if this doesn't work we'll Get someone to look at the pump. Thanks for you help.

Reply to
ab

That's not a bad thing. Please read on.

How is the water replenished in the heating system? You should have a filling loop from the mains water supply to the heating circuit. Does your boiler have a gauge on the front with numbers? The number showing on the gauge should be somewhere near the 1 or 1.5 mark, at least, on the black pointer.

After you bled the air out, how did you put more water into the heating circuit? You have to put more water in when you have taken it out of the radiators.

So the boiler is working fine. Good. The radiators are seperate from the hot water system. They are on a closed loop of pipework that needs to filled seperately from a source that allows the system to be pressurised for the pump to circulate hot water around the radiators. After many years, the heating circuit can become void of water because it has simply escaped. You have to keep the water in this heating circuit, topped up to keep it working.

You may have to get this done if you have allowed the heating circuit to boil off all the water it had in it. The sludge build up will have caused blocks along the thin pipework in places.

But I would ask you first to look for a flexible hose under your boiler. It should have little taps on either end of it, or at least be fitted at one end to a little tap, and will need connected at the other end to allow filling of the heating circuit.

Please have a look for this first. Please Please Please.

Reply to
BigWallop

At that age you might have a dropped-loop system in 6mm tube. The pipes will clog up in the lowest places over that time. That would explain them stopping one by one .

Reply to
EricP

what a fuken thick wanker a boiler cant BOIL offthe water in a close system. iit can only leak out go and lern about boilers

Reply to
Chas

A flush is the last thing I would do, pumps wear, houses settle and pipes can get airlock, does water come out with boiler off and water hot. Is it zoned with zone valves and two pumps. Is it one feed for 2 floors, is there a balance valve off the boiler. Check for high areas off boiler you could get air lock at. Here is a site with only boiler pros,

formatting link
there you should be helped. What did the several pros that came out tell you, over here nobody peddles the flush that I know of. I would guess bad pump or air lock, since it was gradual Id say pump, and its cheaper than a flush.

Reply to
ransley

Just a thought. Are they fitted with TRVs? If so it is worth checking if the valve pins are stuck closed.

Reply to
chudford

Does this help?

formatting link
(My first thought is the pump packing up.)

Reply to
YAPH

Chas - I think that this URL is what you need

formatting link

Reply to
geoff

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.