Boiler not firing up

[gary123]

I have an valiant ecotec plus 630 gas boiler, Honeywell st799 programmer and an old satchwell thermostat.
We only really use the programmer at present to either run the hot water or heating for an hour or so operated by manually sliding the control lever across to 'cont' then turning it off.

Operate hot water switch to 'cont' boiler fires up and works fine, move the heating switch to 'cont' nothing happens.
Boiler has about 1.2bar water pressure, thermostat is making contact when turned up, checked continuity across the connections.
I'm no electrician, but I'm thinking of changing the programmer, as I suspect this to be the problem.
Feel free to advise me where to check/look first by all means, or tell me I'm talking rubbish.
Thanks in advance
Gary.

 

[PlumbBobBob]

i would try a new thermostat first, when you say it is making contact do you mean clicking when turned up?

 

[diamondgas]

About all you can do is check out the external controls or get someone in IMHO gary123... :welcome: to the forum

Is the boiler in the heating hot water position? Why not rule out the stat all together? If you've checked continuity then you'll know what two wires to twist together to do this yeh?

Do you know if the switching of the boier is volt free or is there an expected voltage? Could be worth checking out if power is present if the external controls are not volt free...

 

[SafeGasInstall]

I have an valiant ecotec plus 630 gas boiler, Honeywell st799 programmer and an old satchwell thermostat.
We only really use the programmer at present to either run the hot water or heating for an hour or so operated by manually sliding the control lever across to 'cont' then turning it off.

Operate hot water switch to 'cont' boiler fires up and works fine, move the heating switch to 'cont' nothing happens.
Boiler has about 1.2bar water pressure, thermostat is making contact when turned up, checked continuity across the connections.
I'm no electrician, but I'm thinking of changing the programmer, as I suspect this to be the problem.
Feel free to advise me where to check/look first by all means, or tell me I'm talking rubbish.
Thanks in advance
Gary.

have you tried having ch and hot water the same time , you could be having the old W plan
where hot water have priority over ch
so if you select them at the same time rads should start heating up