I have just replaced the central heating controls with a Drayton Lifestyle with new programmer and wiring centre. The original set up did not have a room stat and the mid position valve(Honeywell) had never worked. It now seems like the mid position valve is working the wrong way round. I have checked and double checked the wiring and everything is connected how it should be. It almost seems like that if I remove the valve and turn it through 180 degrees it will work fine. The other option would be to reverse the wires to the mid position valve, but which ones. Anyone have any ideas?
Hot water and CH working the wrong way round
- Thread starter imartin
- Start date
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Hi Rob! Could give more detail on swapping it over in the programmer, cause I can't see how it could work. If it's wired correct then the valve must be installed the wrong way.
imartin Your programmer has three outputs. one belongs to the CH through a simple on/off switch. The other two belong to the HW side through a 'two way switch'. one is HW ON and the other HW OFF.
HW ON wire goes to cylinder stat (another two way switch) on then to boiler. When stat is satified, power diverted to supply mid position valve (grey wire)
CH ON wire goes to room stat (one way switch) and then on to midposition valve (white wire).
It's the white that gets the valve to mid point and if needed the grey takes over to get the valve to CH position.
Now if the HW was not needed and was not on then, how can the grey ever be live? it can't. So this is where the HW OFF wire is used, this also goes to the grey of the valve.
swapping wires is a non starter. The valve itself may be symetrical, but the actuator head which turns the valve certainly isn't.
It's motor driven, by two different power sources in one direction and and it is reversed by the return spring when power is removed.
In the fully relaxed position the CH port is closed and the HW port is open.
Hence the valve plays no part when HW only is selected.
HW ON wire goes to cylinder stat (another two way switch) on then to boiler. When stat is satified, power diverted to supply mid position valve (grey wire)
CH ON wire goes to room stat (one way switch) and then on to midposition valve (white wire).
It's the white that gets the valve to mid point and if needed the grey takes over to get the valve to CH position.
Now if the HW was not needed and was not on then, how can the grey ever be live? it can't. So this is where the HW OFF wire is used, this also goes to the grey of the valve.
swapping wires is a non starter. The valve itself may be symetrical, but the actuator head which turns the valve certainly isn't.
It's motor driven, by two different power sources in one direction and and it is reversed by the return spring when power is removed.
In the fully relaxed position the CH port is closed and the HW port is open.
Hence the valve plays no part when HW only is selected.
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Thanks for the replys. I think I am the victim of Assumption. Just because the Honeywell valve cover was upright I copied the orientation when fitting the Drayton valve. I re-checked the wiring, wrote it all out on a sheet of A4 and followed it through. It all seemed correct. Fired up the system and followed the path of the hot water out of the valve. Checked the indicator on the valve and with it indicating water, flow was going to heating and vice a versa. Have just removed the valve and refitted upside down according the sticker on the power head. Guess what? my system is now operating normally with the tank stat controlling the water, room stat the heating with the valve in the mid position when both selected. Not sure if the ports are different when both valves are upright of someone had 'tweaked' the wiring before to make it work properly. Heard a good quote in a film "Assumption is the mother of all f*#k ups"
not sure what is meant by 'when both valves are upright'.
There's only one valve spindle, which means one port is open and one port closed, or mid position when both ports are half open (or half closed).
The thing about the mid position is that although the setting is HW and CH the valve fluctuates automatically according to demand. The demand for CH is far more than HW so I expect the valve spends the majority of time in the CH position.
Also when CH is satisfied the valve will stay at the CH position. Its just the output from the orange wire that is cut off, so boiler closes down until there a demand again. There has to be a demand for HW for the valve to drop back to either mid position or the HW position.
The main thing is you've got it sorted, so none of the above is important.
There's only one valve spindle, which means one port is open and one port closed, or mid position when both ports are half open (or half closed).
The thing about the mid position is that although the setting is HW and CH the valve fluctuates automatically according to demand. The demand for CH is far more than HW so I expect the valve spends the majority of time in the CH position.
Also when CH is satisfied the valve will stay at the CH position. Its just the output from the orange wire that is cut off, so boiler closes down until there a demand again. There has to be a demand for HW for the valve to drop back to either mid position or the HW position.
The main thing is you've got it sorted, so none of the above is important.
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