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Mid-position valve problem

Hi

I've been having problems with the central heating where the rads are coming on when the boiler is intended to be only heating the water. I immediately assumed there was something wrong with the mid-position valve.

It is a drayton MA1, where the actuator push-fits onto the valve assemble.

Examination of the actuator revealed rattling parts inside and opening it up I have discovered that the plastic nodule holding one of the return springs has broken, so clearly there was not enough force for the mid-position valve to be brought back to the HW only position.

Ordered a new actuator which arrived at the weekend.

I pushed it into place a wired exactly as it was before, but this doesnt seem to be working at all - always seems stuck in mid-position.

Does anyone know anything about these MA1 actuators? There is a black button at the end of the assembly which sticks out on the old (broken) actuator, but is pushed in on the new one. Does this have to be released in order for the actuator to run freely between its three positions? I gently tried to turn the actuator by using a screwdriver in the valve hole, but it is stuck.

thanks Nigel

Reply to
piloti
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I don't know that model, but they normally have a way to lock the valve in mid-position so you can drain down the system when it's not powered.

Reply to
Andrew Gabriel

I don't know this particular model - but didn't it come with any paperwork explaining it's operation?

Reply to
Set Square

These actuator heads all have a manual operating lever on them, which is used to flood system before full activation of all the equipment. The black button on the side of your one is the manual lever. Have you tried moving the valve itself? It may be the valve that is stuck, and this burnt out the original actuator head. Place a spanner on the valve and move it. If it is too difficult for you to move manually, then the actuator head is really going to struggle.

Don't just blame the electrics. :-)

Reply to
BigWallop

Thanks! I have just released the button and all is working. I should have done that at the start, but it was stiff and I didnt want to break it.

They are obviously shipped that way as most installations will be first time where the mid-position needs to be held in order to fill the system.

Wonder how long it will be before it needs another replacement :(

Reply to
piloti

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