Central Heating Conundrum

Dear All, I have a self-installed combi system that has been happily working for a few years now.

In summer I (foolishly?) decided to add another rad to the conservatory. Foolishly I didn't buy a new one and didn't check for slime/sludge etc in the spare one I had. Since installing, this radiator has never worked properly, the bottom of it warms slightly, flow pipe hot, return almost cold, but it's not really been a problem 'cause it's only in the conservatory.

Since autumn my daughter's radiator (index), furthest away from the boiler has stopped getting hot, and will often become lukewarm or even stay cold. I've tried bleeding this and the other rads which hasn't solved the problem.

Fearing it was crap from the extra radiator moving round the system, I went to my local suppliers to get some system de-sludger and one of the guys there (time-served plumber) said it's more likely to be a balancing problem*. He told me what to do and I also looked at Phil Addison's Balancing FAQ here.

Since going through the process, only three of the radiators heat up properly. The index rad worked for one night then promptly stopped working properly. Flow pipe from boiler doesn't feel hot enough (I can comfortably hold it). Return pipe is tepid.

Can anyone say what might be the cause/s?

Sorry for going on a bit & thanks for your time, Mark

Boxer (Ideal) Combi 80k BTU, 9 rads, microbore, 1.5 mbar pressure

  • He also said inhibitors and other products were a waste of money, systems never had 'em in the old days and were still going strong, but that's another thread
Reply to
Mark D
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It sounds like the boiler may have developed a fault probably the diverter valve is stuck in the HW position. Does the boiler shutdown fairly quickly without heating all the radiators? What happens if you put one rad on at a time?

Reply to
Ed Sirett

This one really does appear to be believed by a number of absolutely cretinous fools. Do not believe it. Inhibitor is essential. Not using is likely to damage the boiler and invalidate the guarantee.

Christian.

Reply to
Christian McArdle

Also helps to lubricate the pump and prevents freezing in extreme cases Blair

Reply to
Blair Malcolm

Snip... Answering my own question but I'm beginning to think it might be the boiler needs venting, I've actually looked at the temp guage for the first time and it's runnning at approx 30/40 degrees most of the time. No wonder the farthest rads aren't warming...

cheers mark mcr (To reply please take the michael)

Reply to
Mark D

Did you verify that the other rads were working ok after this mod?

Hmmm, summer.... autumn.... - Was this the first time you used the system after modifying it? Could it be 'something you did'?

That's amazing! That's the first time I've heard of a plumber that knows about balancing.

It might not be the index rad any longer - it could now be the new rad if it's far away.

If the flow pipe is not hot it must be one of two things (or both!); It is a waste of effort trying to balance if the flow is not heating properly.

1) Water not circulating: Pump bust, valve not opening, all rads shut, system sludged up, airlock... 2) Burner not working: Control problem, gas problem, .... umm, over to Ed Sirett.

No problem, you're welcome.

80K is a big boiler. If it was never heating properly I would check that the micro-bore is up to the loads required. You do mean 1.5 BAR don't you!

Phil The uk.d-i-y FAQ is at

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Reply to
Phil Addison

My brother had a system fitted by a BG approved company at about the same time as I DIYed mine. Some 25 years ago. I used inhibitor from the start - his supplier agreed with your plumber.

He's had several rads replaced through rot. Mine are all original - despite being Thermapanels with rather thinner than average steel work - and a reputation for leaking.

Now one swallow don't make a summer...

Reply to
Dave Plowman (News)

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