I have a potterton boiler and is fitted with a myson 3 way. I can either have CH on by itself or HW on without CH or both at once. My problem is that when l have CH on only it also warms the hot water up. The switch id in AUTO position but add soon as CH is put on the switch goes to MID. ie it opens the outlet to the hot water coil and sends the hot water from the boiler to the hot water tank. If I manually try to poor it back to AUTO it won't let me add it seem the switch is loose and isn't connected to the valve etc. When l switch CH off the switch goes back to AUTO again. Any suggestions what the issue could be here.
Hi You haven't said exactly which Myson valve you have, so I'm taking a guess. The manual lever on the end of the valve will feel odd, as it is only used to partially open the valve for system filling/draining purposes, it will always return to AUTO on it's own. If you are saying that you are unable to get the valve to CH only, so it is not fully opening, then you either have a faulty valve, or there is a wiring fault. So we need more information. Valve model, and how did this problem start, and has anything been done to the system ? A photo could help.
I have just took s couple of pics but dont know how to upload? Yes you're right it doesn't automatically go back to AUTO. the lever feels loose as the actual valve that turns seems to have freed itself from the lever. I have took it off and put the valve back on the lever casing but it comes out again when it turns to MID. Si in essence the lender is still at AUTO. But the valve had turned. However if l switch the power off then the valve goes bavk to AUTO ( but again turns ti MID when power is resumed) How do l upload pic?
Hi Please do not take too much notice of what that MAN/AUTO lever does, and how it feels. As I have said, the valve may be faulty, or there could be a wiring fault. You have not answered the questions I asked, so I suggest you call for some professional help to diagnose the cause of the problem.