Drayton motorised valve never goes into mid position ????

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Hi guys can anyone confirm please if this is normal

I had a new boiler and accessories installed a yaer ago and all has been working fine both hot water and heating APART FROM ONE THING

The Drayton MA1 valve only ever seems to be in H or W mode and I cant seem to get it to offer both ie/ hot water AND heating.

I have never once seen it in M position where it is feeding both HW and Heating at the very same moment - is this correct do you think ???

 

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If both hot water and heating are calling for heat at the same time (programmer on and both thermostats not satisfied) then the valve should move to the centre position. If you can test safely, the signals to the wires on the motorised valve should be.

White (Heating required) should be live 230v
Grey (Hot water not required) should not be live

If these conditions are satisfied, suspect the motorised valve. It has a limit switch and a diode that 'stall' the motor in the central position. My guess is that one of these is faulty.

Are you sure it's a MA1? Drayton do make other models of valve such as the ZA3 which only work as you describe, but the MA1 does have a centre position.

 

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many thanks for your reply and mine is defintely the MA1 (says so on casing and I have the paperwork here too) and yes Ive been expecting to see it in centre M position at some point but it never does that just goes straight past to H or W. It was brand new on installation and has never been in centre position - I will look at your suggestion now - many thanks