Honeywell st7100 attached to potterton 50e not working.

[staff18]

At this moment in time (31/12/12) I haves no hot water or Central Heating. I cannot get the boiler to fire up. I can program the Honeywell ST7100 on the potterton 50e but as soon as I press RUN button the display goes blank.

There is no red led power when I try and push the extra hour. I thought that they were not being powered, but they seem to be wired right in the honeywell panel. Everytime I set the time the display just flashes. When I press set it moves onto setting the day.

I have changed fuses, Had a new 3port diverter switch, Changed batteries on st7100 and tried to reset the boiler (It will not allow me to as it is already set) Need to know what to do if it is the timer causing this problem. Thanks. Dannie

 

[45yearsagasman]

The st7100 is now quite old and it does sound like its faulty. The only way is to test the outputs from the timer, and is easiest done at a wiring centre(if you have one).
There is, I believe, no direct replacement for the 7100 and any new programmer will require a rewire to a new backplate.