central heating

[arsenal 10]

Can some body please tell me why my central heating wont work with out haveing my hot water on ?

[Loosehead]

Well what do you think makes the radiators warm?

[arsenal 10]

i should be able to have them on seperately , because why would there be two different settings , 1 for heating ,1for hot water .
loosehead dont bother replying unless you have got a constructive answer , this is supposed to be a helpfull forum .

[Loosehead]

In order for the radiators to get hot they fill with hot water. The system for creating hot water is known as a boiler. The boiler is common to the heating and hot water system as is the cylinder where the hot water is stored. Therefore in order for the heating to be on the hot water must also be on. You can of course have hot water and no heating.

[Noweia]

In our house the boilers for the central heating and hot water are separate.

If your house is the same, then if there is a problem with the central heating boiler then the central heating won't work without the hot water being on.

[gasman]

Crikey arsenal you havent had much help here mate.
Take no notice of earlier posts, and concetrate on getting your 3 port moterised valve fixed as yes you should be able to have hot water on its own or the haeting on its own or both if you so desire. but this can only work if your 3 port is working .

[arsenal 10]

Tanks a lot gasman , will get it sorted .

[Pharlap]

I will admit in my ignorance I thought Loosehead's proper answer was good.
Is gasman seriously telling me that even with a 3 port thingamygig, if I have my central heating on hot and I went to run a bath I would not have any hot water. I only have one cylinder the hot water in it must surley supply the taps and radiators

[solera]

you need to appreciate that inside your hot water cylinder is a coil which is in circuit with your radiators, your boiler heats the water in the cylinder and it is this hot water that heats the coil and radiators. You can thru the 3port valve turn off the radiators but the only way to turn off the hot water is to turn off the boiler, then no hot water and no hot radiators, have a look at one of the Wickes central heating guides and all will become clear.

[Hammer Head]

I had the opposite problem. My water wouldn't work, but would heat up if the heating was on.

I finally managed to trace the fault to one of the two motorised valves in the airing cupboard (probably the same ones refered to by gasman).

There is one valve in the heating line and another in a 'T' joint going to the tank. It was the one going to the tank that was the problem. Because it is motorised and therefore has moving parts, it had become clogged with dust. I cleaned it out and gave it a squirt of oil and Hey Presto the hot water worked once again.

Let me know how you get on

[gasman]

To everyone else who has posted replies here
The three port diverts the hot water from the boiler to either the hot water cylinder via an inner coil to heat the water for the hot taps without having to have the heating on.
Or it diverts the hot water from the boiler to the radiators with out having to have the hot water on. Or the three port will stay mid position if the hot water and heating is required. so you can have just heating alone or hot water alone or both if you wish. It is rubish to say that you can not have heating unless you have the hot water on aswell or the other way round.

[Hammer Head]

Gasman - get your facts right.

I have a timer switch for my heating and hot water. The heating worked normally on the timer but the hot water would not work on its own. I had to turn the heating on to heat the water. Not really a good idea in the middle of summer.

After sorting the valve out I have cured the problem and it now works.

[gasman]

My facts are spot on Hammer Head, you could'nt do it because your motorised valve had packed up. Your timer as you call it (programer ) is linked to the motorised valve and tells it which one to do Hot, Heating or both ! Now it has been fixed i bet you can have hot water without having to have the heating on as well, I'm am not called Gasman for the fun of it, i am a fully trained CORGI heating engineer with twenysomething years off expeirence.

[johnny37]

gasman - My hot water packed up once and it was quite expensive to get someone in to replace the motorised valve. He actually drained the system down. I've learned since how to suspend the water in the system without having to drain it down. Can I deduce from the above posts hat it is a simple job or is it a trade secret?

[gasman]

It is a simple job johny37 with the right tools and the correct knowledge ;o)

[knobbynonuts]

If it is a very old system then sometimes that was how they were wired to do,what type of programer do you have, one of the most common old ones were a randall which was a big oblong ugly lump I think it was a 30/20 or if it is a newer programer then sometimes there is a little sliding button at the back of the face of it that might be set so you cannot switch the heating on without the hot water,do you have one diverter valve or two?
And on a lighter note have you been to the new emirates stadium yet, and if so did you find it like me tottaly void of atmosphere unlike highbury........

[arsenal 10]

Its a potterton timer , only got one diverter valve .
Yes mate ground is superb .

[blueknight85]

I imagine the question poster is talking about a gas combi boiler not a cylinder from the dark ages known as a storage heater that stores water and heats it through an electrical element.....
and by hot water on i also through common sense imagine he/she is referring to having the hot water tap running in order to get the radiators to heat up