How to replace Mid position actuator of Drayton Mid-Postion Valve

[Canvas Fran]

I think the actuator on our MA1/679 is faulty/sticking, but am not sure how to get it off to replace it. It was fitted so that it is touching one of the pressure vessels. The leaflet left by the plumber doesn't really help.( I tried to post a link to a pdf of it here, but the forum doesn't allow it)

This is a photo showing the valve and actuator - I would appreciate any advice.

https://goo.gl/photos/GMaKqjCdmiFdkcX79<br><br>Fran

 

[stani]

Unfortunately you need to get someone in to replace that, it looks like the expansion vessel will have to be removed to allow the head to be replaced, not really a diy project.

 

[joni os]

If the expansion vessel indicates an unvented cylinder, I have concerns about the 3 port valve.

 

[chris watkins]

As above, do you have an un-ventred cylinder i.e. one fed directly off of the main water supply?

Why do you think the head needs replacing ?

 

[Canvas Fran]

Yes - it's a pressurised system. Think it may need replacing because every now and then the boiler doesn't fire even thought the stat and controller tell it to. Going to the valve actuator and waggling the little lever usually solves this, but I know isn't a long-term solution.

 

[chris watkins]

No please don't touch almost certainly your problems are due to it being installed incorrectly and you will need to employ someone who holds a Part G / un-vented ticket* to come & correct the missing 2 port that should have been installed with the 3 port.
(*it is a legal requirement to be able to work on these systems)

Changing the head of the 3 port will make no difference at all if I am correct, it will just do exactly the same.

 

[chris watkins]

Don't touch Please,
I had one of these on Monday, what is the matter with these installers can't they read the instructions !!!

Oh no sorry forgot they can't reads English.

Why do they think a 2 port is supplied with the cylinder & it is not so it can be sold straight afterwards on eBay.

 

[Darren Jackson]

Hi, you say it a pressurised system. Is that the heating side only or is the hot water cylinder also pressurised ie. Unvented? Because if it is you got problems and definitely need a G3 engineer.

 

[Canvas Fran]

Hi, you say it a pressurised system. Is that the heating side only or is the hot water cylinder also pressurised ie. Unvented? Because if it is you got problems and definitely need a G3 engineer.

Yes, the hot water side is pressurised too. The system's been in for 10 years or so. Had the valve replaced about 3 years ago.