The room stat has been changed,so.
(a)You need to confirm the 'white' wire leading to valve now becomes live with CH ON and stat turned up.
(b)The 'grey' wire of the valve needs to be live when the HW is on and in a satisfied condition. (power coming from the 'satisfied' terminal of the cylinder stat). This is to move valve from mid position onwards.
(c)Now if HW is not on the 'grey' still has to be made live so.The 'grey' wire of the valve should also be live when HW is OFF at the programmer. (power coming from the HW OFF terminal of programmer)
The above three requirements are easy to check.
Power on the 'white' gets the valve to mid position.
Power on the 'grey' takes over and gets the valve to the CH position, which also results in power coming from the 'orange' wire.
In hindsight you could have bench tested the valve by applying power to the 'white' then 'grey' wires (together or separate) and test 'orange' and verify valve moves over the full range.
If the fault relates to (b) or (c), it may be a case of a missing wire, or the incorrect type of device fitted. By that I mean the programmer may not have a HW OFF terminal hence no live 'grey' wire.
(a)You need to confirm the 'white' wire leading to valve now becomes live with CH ON and stat turned up.
(b)The 'grey' wire of the valve needs to be live when the HW is on and in a satisfied condition. (power coming from the 'satisfied' terminal of the cylinder stat). This is to move valve from mid position onwards.
(c)Now if HW is not on the 'grey' still has to be made live so.The 'grey' wire of the valve should also be live when HW is OFF at the programmer. (power coming from the HW OFF terminal of programmer)
The above three requirements are easy to check.
Power on the 'white' gets the valve to mid position.
Power on the 'grey' takes over and gets the valve to the CH position, which also results in power coming from the 'orange' wire.
In hindsight you could have bench tested the valve by applying power to the 'white' then 'grey' wires (together or separate) and test 'orange' and verify valve moves over the full range.
If the fault relates to (b) or (c), it may be a case of a missing wire, or the incorrect type of device fitted. By that I mean the programmer may not have a HW OFF terminal hence no live 'grey' wire.
