boiler does not fire when timer comes on - unless HW also on

[jackthom]

With the meter set to continuity you get a beep when the two probes are touching each other and in the same way a section of wire can be checked for breaks by placing the probes on each end.

If the wire is OK it will beep (and may also give a very low reading of resistance.)



Alternatively if you can figure out a way of safely measuring the voltage of CH ON directly at the back of the programmer backplate, that should indicate whether the programmer is faulty.

 

[jackthom]

Just run the continuity test and the instructions say there is an audible warning if below 50 ohms.
The warning goes of and the reading is 003. Unfortunately I cannot interpret what this means. Is it just the wire that has broken and would it be worth replacing this before I replace the timer?
Thanks

That indicates the wire is connected OK so the timer must be faulty.

 

[Fireblade01]

Oh it appears the audible beep is a good think and not a warning, sorry a total novice at this!
Seems to me it is the timer!

 

[Fireblade01]

Thank you for your assistance. Off to get a replacement timer.
Really appreciate your help.

 

[jackthom]

Yes the timer looks guilty to me.