CH Questions

[hays]

I have a few q's about my CH which I hope makes sense to those members who understand these things SO much better than I do...

First off, I have a pumped system. 3 way motorised valve, hot water cylinder in airing cupboard etc

I've noticed my boiler comes on for 5-10 minutes then goes off. 5-10 minutes later it comes on again. Is this normal ? It's overdue a service - probably not been done for 5 years

The 3 way valve in my pumped CH system makes a continuous ' operating' noise I had a quick look and was able to stop it by pressing the metal cover. Eventually I loosened the screw holding the cover in place and the noise stopped Is this normal or is my valve on it's way out

Finally is there any rule for which setting to use on the pump. I've turned it down to 1 as it's quieter. Could this affect any of the points above

PS: I have plenty of HW and CH

As I already have a faulty programmer, I'm wondering if I should get a British Gas contract for a year and get things sorted ?

[Andy Hall]

This is completely normal behaviour during periods when there is demans for heat because the room temperature is below the room thermostat setting.

There is some form of thermostat in the boiler itself, which generally is set to provide water from it for the CH and HW circuits at about 80 degrees in conventional boilers. When this temperature is reached, the burner stops but the pump keeps running, moving the heat to the system. Then as the water cools through the radiators, the boiler fires up again. 5-10 mins each way is perfectly healthy.

Another scenario can be that the room stat is operating on and off, but normally the room temp does not change that rapidly.

I wouldn't necessarily be concerned about that, although a safety check is a good idea.

This is normal as well. The valve is held in one position by a motor which is powered as long as it is required to have the valve in that position. The motor actually stalls but the 50Hz current from the mains causes a vibrating or even buzzing sensation.

Generally the pump should be at the lowest setting which causes all the radiators still to be warm. If you set it too low, another effect is that the boiler on/off times will get shorter, simply because you are not getting the heat away as fast.

If it works on (1) then that's fine.

No. BG contracts are a disappointing ripoff. They do not provide the level of service that their advertising implies. You would be better off findling a good local heating engineer. .andy

To email, substitute .nospam with .gl

[Set Square]

The one thing on which most people in this NG are agreed is don't touch BG with a barge pole! They will use your contract as a means of trying to sell you all sorts of expensive services (power flushing etc.) and replacements (new boiler) which you don't need. Even if you do need these, they would be far cheaper elsewhere.

[Bob Smith]

And they may not repair existing problems.

Bob

[BillR]

They definitely won't. They may not even take the system on contract without a major overhaul. They aren't very good but they are not so stupid as to e.g. replace a faulty programmer for nothing. Save your maintainance contract money and in only a few years you'll have saved enough to buy a new boiler anyway.

[Simon Avery]

Hello hays

It's not that unusual. It's cutting off because the water in the boiler is getting too hot. That could be due to a partial blockage, failing pump, undersized pipework, air in system - a whole host of "water not moving as fast as it should" issues, or it could be completely normal.

The bottom line is: Is my hot water hot, and are my radiators cosy?

Anything else is irrelevant. (Leaks and explosions aside)

Get it done. I don't think it's worth trying to do yourself even for an experienced DIYer, seeing as the testing equipment costs so much.

If it works, it works. Hard to figure out what you mean - noises don't transfer well to ascii, but the only answer I can give is "It /might/ be about to go". It might not, why worry until it does?

Could affect the boiler cycling. Try it at two for an evening and see if that fixes the cycle, although 5-10 minute cycling is /not/ that severe, that's about what mine does. Under a minute and something's gone wrong, though.

Pfft. What is it now, 150ukp? The boiler service is useful, but they tend to run away if they notice something's going to break expensively soon and won't renew the contract. There is something to be said for the peace of mind it gives, too.

A CH pump is

[hays]

Thanks to everyone who took the time to reply - most helpful as usual

-- Regards

Hays

T610 Housings in stock now!!