Problem with central heating clock or solenoid?

[sstaffsw]

Hi, I was wondering if someone could help please...

Although my central heating clock appears to be OK with all the lights lighting up the correct way my boiler is not igniting, there is also no noise or vibration on the solenoid on the boiler. I've had a problem with the Honeywell ST6400C clock before but solved it by cleaning the tracks on the circuit board inside it, but this time to no avail.

I suspect a problem with the clock but does anyone know what I should be metering at the solenoid end? Thanks in advance.

 

[ollski]

Is there 240v at the live on the mains connector on the boiler?

 

[sstaffsw]

I've metered the live and neutral going into the control box on the boiler. It reads zero volts.

 

[ollski]

Then link across the live 240v in the clock and hw on and ch on, then see if you get a live supply in at the boiler, if not you can rule out both of those and check your valves, switches and wiring.

 

[sstaffsw]

Interesting...

By shorting across the 'HW on' and the live, the boiler lights up. Nothing happens if I short across the 'CH on' and the live.

So, does that mean my clock is knackered or is it something else?

 

[ollski]

well if it lights when you short L to hw on but not when you replace the clock and switch the hw on then yes you clock is shot. Perhaps if you explain the fault we could start a bit more logically.

 

[sstaffsw]

Guess what, after putting the clock back on the plate the boiler fires up from the switches as normal. I reckon there is an intermittent fault on the clock, and like I said in my first post, I've had problems with this thing before...

Thanks for your help and advice, Ollski.