Boiler not lighting up on one channel

[ian29gte]

Bit of an odd one this, and I'm completely mystified!

I have four circuits, one for each of the three floors heating, and one for the hot water. The ground floor heating circuit thermostat clicks on and off, and the 3-way valve opens up when it does, but the boiler won't light. Everything works OK one all the other channels, though.

The timer is an old one, a Sangamo Quartzmaster, from 1988.

I don't have a wiring diagram for the system, and I wonder whether the programmer channel could be faulty, even though it shows a light on for that channel.

Any help appreciated!

 

[chris watkins]

If there is movement of the zone valve it is likely to be the end (micro) switch which is not making as this is used to signal the boiler to fire.

 

[joni os]

As above, if zone valve opens programme is calling for heat and valve energized. Manually opening the valve against the spring a few times may loosen the mechanism and allow contact with micro switch.

 

[chris watkins]

As above, if zone valve opens programme is calling for heat and valve energized. Manually opening the valve against the spring a few times may loosen the mechanism and allow contact with micro switch.

Do it hard & fast,

& the same with the valve as the paddle should then hit the micro-switch.:wink:

 

[Unregistered]

Had a good look, the tab was not contacting the microswitch. On pressing the switch, the boiler fired up fine. Gearbox felt good, so as I had a spare synchron motor, I fitted that.

All works a treat now, maybe the old motor wasn't rotating far enough?

Anyway, many thanks chaps!