CH only comes on when DHW comes on Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[NovaNath]

Potterton Prima F with EP2001 control.

The DHW functions as it should.

The CH thermostat was turned down for the summer; when turned up to activate the CH, the boiler will only fire if the DHW is already on/coming on at same time as the heating.
Where the hot water is not on, the boiler makes no noises at all/no response. However the CH light iluminates on the valve and it hums/clicks quietly.

Any help greatly apreciated.
(my gut instinct is that it may be the EP2001 control not telling the boiler to fire)

[NovaNath]

Diagnosed to the actuator on the three way valve

[htg engineer]

See looking through other questions and answers in the forum often leads to the correct diagnosis - there's been many many posts on this subject.


htg