Central Heating not working post winter shut down

[seftonbarn]

Here goes - first post - go easy on me.

I have a Conventional system (open vented) (I think), quite old (in fact start as you mean to go on, very old (20 odd years plus)). The radiators are not getting hot; these are the facts:

Bolier HW heating no problems.

Normally when the electrical thermostat in the hall is turned up I can hear the boiler kick in. But it is not now. Took thermostat off wall, shorted out 2 leads, boiler didn't kick in so assume thermostat is OK.

Pump is running.

Took central heating progammer off the wall and it has 5 wires to a panel (Live, neutral, earth and 2 back cables (but didn't want to try shorting any of these out)).

Any advice would be appreciated.

 

[Rickster123]

Hello seftonbarn and welcome! In your airing cupboard do you have a 3 port valve or 2 2 port valves? Should be a white or silver box attached to a brass valve.

 

[Simon F]

welcome to the forum.
you are on the right track, the boiler is working so the problem is somewhere else.
most likely as suggested a motorised valve issue.
its an old boiler, is the hot water pumped? are there 2 flow and returns or 1?

 

[mountainman]

Pump might be running but not circulating.

 

[seftonbarn]

Hello seftonbarn and welcome! In your airing cupboard do you have a 3 port valve or 2 2 port valves? Should be a white or silver box attached to a brass valve.

Think 1 of 3 way. Certainly I can only find one in loft (bungalow)

 

[doitmyself]

Do the rads get hot if the hot water is on at the same time? (Turn the thermostat on the side of the HW cylinder up to make sure it is calling for heat.)

 

[seftonbarn]

Do the rads get hot if the hot water is on at the same time? (Turn the thermostat on the side of the HW cylinder up to make sure it is calling for heat.)

No. No heat in rads at all.

 

[Rickster123]

On the 3 port valve there should be a leaver. If you move it across does the boiler fire up?

 

[seftonbarn]

On the 3 port valve there should be a leaver. If you move it across does the boiler fire up?

Oooh. Don't think there's a lever. Will check for sure tonight.

 

[seftonbarn]

welcome to the forum.
you are on the right track, the boiler is working so the problem is somewhere else.
most likely as suggested a motorised valve issue.
its an old boiler, is the hot water pumped? are there 2 flow and returns or 1?

There is a total of 2 pipes connected to the boiler. Don't know if that answers question regarding number of supplies and returns

 

[Simon F]

there are so many variables as to how it could be piped up.
some pictures of the controls/pipework/valves etc especially to the airing cupboard might prove helpful.
the other answer is call someone to take a look.

 

[seftonbarn]

Hello seftonbarn and welcome! In your airing cupboard do you have a 3 port valve or 2 2 port valves? Should be a white or silver box attached to a brass valve.

Yes - definately a single 3 way valve.

 

[seftonbarn]

there are so many variables as to how it could be piped up.
some pictures of the controls/pipework/valves etc especially to the airing cupboard might prove helpful.
the other answer is call someone to take a look.

Don't suppose this helps does it?

 

[jase158]

next to the valve (by the black cable) is your lever, try pulling it away from the cylinder and pushing down, the lever should stay across.

before you do this, make sure the thermostat and programmer are both calling for heat.

if this fires the boiler up then this valve is faulty.

 

[seftonbarn]

Thanks Jase; your a genius. Moved small lever across and bingo; the system kicked in. Looked on screwfix etc to find replacement and noticed that there are many variables. Please can someone help me with which one I need. The one fitted is made by Honeywell.

 

[seftonbarn]

On the 3 port valve there should be a leaver. If you move it across does the boiler fire up?

Thanks, yes there was a lever; moved it across and all worked so looks like a valve replacement. Thanks.

 

[colchesterplumb]

This is the one you want if its 22mm.

Honeywell V4073A 3 Port Motorised Valve | NoLinkingToThis

This is the one you want if its 28mm

Honeywell V4073A 3 Port Motorised Valve 28mm | NoLinkingToThis

However.... I would say those prices are rather steep. If you're going to be calling a plumber out I would let them get it from the merchant as would more than likely save you a few quid.

Nick

 

[Millsy 82]

The honeywell are the best for quality but they are quite expensive. I personally fit drayton instead as they are still a good quality but quite a bit cheaper. Try and steer clear of the really cheap ones otherwise you will end up having to replace it again in the next couple of years.