Drayton MA1 - Looks like a motorised valve head problem?

[Skyhigh]

Our MA1 sometimes (about 10 times in the past 14 months) 'sticks' in a non-resting position (i.e. Mid or Heating).
The only way to 'reset' it is to remove power from the unit via the isolator switch.

When power is removed, it goes back to a 'resting' position (W)ater.

The spindle on the valve itself seems OK but not great. It moves without being forced but 'squeaks' a bit (applied some WD40).

Does this sound like a problem with the motorised head itself rather than the brass valve/spindle sticking?

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I've replaced the motorised head* but it's hard to tell if the problem is fixed as it was so irregular.

Oddly, this valve seems to rest at H or W.
(I assume 'W' was a resting position, but looking at forums sometimes 'H' can be too depending on what the valve has just been doing...?)


Any help appreciated.

(I'm tempted to change the brass valve too just to be sure it's all sorted.)

 

[oph]

Valve most likely sticking on the inside or letting by. Bin it off and fit a Honeywell. Draytons are ****e

 

[Skyhigh]

Do you mean the brass valve body or the motorised head unit?

I've already been thinking of replacing it with a Honeywell as we've had failures with MA1's in other houses. I'm assuming it uses a different brass valve body? (rather than just switching out the head)

 

[oph]

Yea, you need to drain it down im afraid as they arnt compatible