Glow-Worm combi no dhw

[kev16]

Glow-worm Swift-Flow 100 combi boiler. No hot water, I have changed the flowswitch and main and control pcb's. It only works for a few minutes from cold in the morning then no more hot water. Central heating works ok.

[ianess]

Could it possibly be that your heating water temperature is set higher than your domestic hot water temperature in which case the boiler will never be cool enough to switch your `hot` water on??? Try setting the DHW thermostat [on the boiler] to a degree or two above the CH and you may find your problem solved.

[kev16]

thanks for the reply, I hope the problem is now fixed, it was the dhw thermistor