Boiler starting up when swiched off at timer?

[JBP Heating]

Yes do that if you can to figure out which one it is. Sounds like a sticking microswitch in which case you will need to run the heat and water to open the valves and maybe the switch will stick again. Valve heads can be replaced.

 

[stevetheplumber]

you realy need to check if its the boiler or the system as said you cant legally work on the boiler but removing the cover isnt affecting the combustion side but you can fault find from the s plan junction box provided it has been wired correctly the grey and orange wires from the valves are the ones to start with
grey is power out from the boiler and it then passes through both micro switches in paralel and comes back on the orange wire to fire the boiler i would disconnect them both and use a meter to see which valve,if either is making the circuit i very much doubt this is a board fault

 

[James 3454]

Thanks Guys, ive been switching the heating on and off the past few days and the problem has not re appeared, so i think im just going to leave it for now, i know what its likely to be should it happen again.

Thanks again for all your help guys, it is very much appreciated.

Cheers.

James

 

[James 3454]

Hello Again. The problem has returned, I tried pushing both the levers on both valves, one was stiff and sprung back, the other was loose. Nether turned the boiler off... I tryed it with the hot water switched on, and then with both the heating and hot water switched on, but its the same, one is stiff and springs back and the other is loose.

So I'm thinking there is demand when there shouldn't be on the one that's loose all the time, but I'm unsure as to why the other one does not go loose even if i switch both the heating and hot water off, am i correct in thinking it should do?

Again many thanks if any one could help me out here?

James

 

[JBP Heating]

Hello again. The lever will be loose when there is demand and the valve has opened.

 

[heliotrope]

Turn off the electric supply to the boiler at the fused spur or pull the plug at the socket.

Don't just switch off at the programmer.

With no power to the system both valves should be closed and the levers would be firm.

If one is still floppy this would indicate a fault and the micro switches contacting and would
keep firing the boiler when power restored.

 

[James 3454]

Thanks guys, ive been switching off at the consumer unit, one is still loose when its switched off so ill investigate that one tomorrow.

Thanks again.

James

 

[James 3454]

Hello again, Ive had a look at the valve and you were right, the lever was stuck on the switch, i rotated the cog so the lever came off the switch and now its working fine again. The switch seems to be working, its switching the boiler on and off, its the valve getting stuck open thats causing the switch to be depressed, is this likely to be gunk built up in the valve for the hot water system, or will the motor have gone? I was thinking i might take it out and clean the valve out.

Thanks again guys, i think we have got to the bottom of it.

Cheers.

James