Heating only works when hot water is on.

[mquinton1980]

Hi all

My apologies I know very little about plumbing.

I have a central heating programmer that allows you to choice 2 on/off settings for both the hot water and central heating to come on. The 1 clock controls both so you can't have 1 service on for a shorter time period than the other. However there are times when the house is cold and we want to bring the heating on but not the hot water, however switching the heating on to constant or pressing the advance button does nothing unless we also turn the hot water on.

In our airing cupboard we have what looks like 2 motorised valves (forgot to take a picture). These are on seperate sections of pipe. When you turn the heating on alone you can hear the valve working and a light humming noise indicating that things seem to be working ok.....however the radiators will not heat up at all. Unless we turn the hot water on aswell.

Please can you point me in the right direction as to where the fault would possibly be? I want to get a new programmable room thermostat but there is no point until we can get this sorted otherwise the only way the thermostat would bring on the heating is to have the water on permantly.

P.S we have an Ideal Classic RS30 (quite old) with a gravity tank in the loft and hot water cylinder in the airing cupboard.

Please help.

Thanks

Mark

 

[mquinton1980]

Can anybody help please? Would be much appreciated.

 

[45yearsagasman]

If you have 2 motorised valves then you have S plan configuration and your symptoms would suggest a fault on the CH zone valve. Depending on make,it can be a simple repair or at worst a valve replacement. Post a pic of the zone valves and as much as you can of the other parts of the system in the AC.

 

[bigpkr]

From what you say, the ch valve doesnt sound like its fully opening on demand so therefore not making the end swtich and firing the boiler.

Could be a head swap or maybe head and body depends on make.

 

[bigpkr]

Just notice its got gravity hw, has it always been like this or is the "fault" something that just happened?

 

[mquinton1980]

Thanks.

I think it's been like that since we moved in and to be honest we've done nothing about the fault as yet. It's only bothered us when we want one on but not the other. But rising bills have now made me think differently and I want to save as much as possible and this is the first step.

There are definately 2 valves in the airing cupboard, i'll see if I can take a picture tonight of the arrangement and post it on here for you to see.

I appreciate you guys coming back to me. It looks like a valve fault somewhere from what you are saying.

Thanks

Mark

 

[45yearsagasman]

Just notice its got gravity hw, has it always been like this or is the "fault" something that just happened?

There are zone valves so probably not gravity HW.

 

[mquinton1980]

Ok so to add to my previous messages.

I had a plumber round today who is moving my stopcock to a different location. Whilst he was there I asked him why my heating only works whilst my hot water is on.

He said it could be a valve problem or incorrect wiring of the programmer. So whilst he was there I turned on the central heating via the programmer but not the water, he said that the one valve closed and the other opened indicating that they are working and also that the pump was running and the boiler had firec up. He couldn't understand why my radiators are not heating up. He is on a tight timescale today and cannot investigate further.

Any ideas what could be the problem, a sparky friend had a look the other day and he said he couldn't understand either.

Thanks

Mark