Apologies if this has been covered before, but I haven't seen these symptoms elsewhere.
I have an old Drayton 679H340-3OLO mid-position valve. When the HW is on alone the CH comes on too with no control from the room thermostat. It appears that the valve is in the mid-position. However the indicator is at W. In fact the indicator is always at the correct position whether HW, CH or both are switched on. When CH is switched on alone the pipes to the HW tank seem to be cooler than the CH ones, so I assume the valve itself has moved. I may be mistaken on this though.
A further complication is that there is other pipework less than 1 cm from the valve head making it impossible to remove the head (or replace it) without removing the whole valve.
Any suggestions?
I have an old Drayton 679H340-3OLO mid-position valve. When the HW is on alone the CH comes on too with no control from the room thermostat. It appears that the valve is in the mid-position. However the indicator is at W. In fact the indicator is always at the correct position whether HW, CH or both are switched on. When CH is switched on alone the pipes to the HW tank seem to be cooler than the CH ones, so I assume the valve itself has moved. I may be mistaken on this though.
A further complication is that there is other pipework less than 1 cm from the valve head making it impossible to remove the head (or replace it) without removing the whole valve.
Any suggestions?
