Potterton Promax 15 SL
With wall control PS2 dual channel control.
Shows light heating timed
Heating set to off so with H water set to timed the boiler should fire up when it senses hwater heat needs to be topped up, it isnt. Test: Both heating and hwater lights were set on timed still no boiler fire up would this be timer fault or boiler fault?
Thank you

Bob uk, August 2018

Its not just the state of the timer, is it? With hot water and heating set to "ON", check the thermostats for hot water and for central heating are both demanding heat.

One would be tempted to suggest getting someone competent and Gas Safe certified to look at it

egweryer, August 2018