No hot water unless daytime switch is used

Hello,

I have an issue at the moment where I am not getting any water if I am just using the overnight heating option on my boiler. If I use the daytime switch I then have hot water for about 10 minutes, then it goes cold.

Any thoughts would be great, I had my PCB replaced about 18 months ago by Mike (I believe it was mike)

This is usually the large relay that switches the heater on, it is located below the pcb on the pulsacoil A class. Try switching the two large grey relays over. If one of them still works its going to be the right hand one, pull it out and insert it in the left hand holder. Obviously to do this the cover has to be removed and the power isolated at the on off switch.

Before switching them around look closely at the wires connecting to the grey relays sometimes they are burnt out, and require replacement.

Check the following:
1. Bottom element
2. Bottom element thermostat rod
3. Supply
4. Relay contactor