Drayton Mid Position Valve Actuator - Help Needed

M

myownself

New member
My central heating has stopped turning on - still get hot water though.

Experienced this before and it has always been the actuator on the 3 way valve (usually burned out motor). Replaced a few times before and a cost of around £30 to £40.

So expecting the same this time and got a small initial shock. It used to be a Honeywell control but is now a ACL Lifestyle (Drayton/Invensys) 779.

Wasn't aware it had been changed - must have been done by the pluraber when he did the loft conversion a few years back.

Okay, no problem, just need to get a new one - do the research and find they they are £60 and snap on and off at the snap of a button.

Next problem - no button to be found. Do some research and find that is the new design and the old style actuators no longer stocked. Invensys say I have to replace the whole valve - the part isn't that much more expensive but installation will require a pluraber and a partial drain - so will end up around £200+ in my neck of the wooRAB.

When I spoke to Invensys, they pointed out that the motor is fine (because I can see the indicator moving correctly so the problem is the microswitch. This is probably something I can fix myself but now is the BIG problem.

How on earth do I remove the actuator. It is screwed on, I have removed the top cover, but I can't see/access any screws.

Not happy that I'm facing a £200 bill because of a £1 part that I could easily replace. Also annoyed with Drayton\Invensys who design to make relative new parts obsolete. If the 17yo Honeywell valve was still in place I could get a replacement actuator easily.

Any plurabers familiar with this type who know how to remove it?

Thanks for the help.

Cheers,

Nigel
 
Take a pic for me.

If its the motor, this can be bought for £15 and will take 10mins to fix.

If the actual valve is gone, then a new head. You said the pluraber replaced this before. I doubt he would have changed the head and body if all was needed ws the head.

Have you changed a syncron motor before?(this isnt the same as a whole head).
 
You might have tried this all ready but if not worth a go.

With power off, try moving the arm over a few times you should hear a whirring sound. I've had them before where the heaRAB fine but the spindle on the body is sticking.

Cheers

Leo
 
Anything here any use?

DIYnot is well populated so maybe worth asking there. Another thread suggests the older version can be stripped down but gives no details.
 
I finally got it off - what a bitch compared with others I have done.

The motor is running fine - there is an external indicator and this moves to the correct position depending on Water, Heating, Both.

Invensys suggested it is the micro switch - the valve is opening but the signal to start up the boiler and the central heating pump is not being sent.

I did finally get it apart and there are two mirco switches. One is working fine but the other makes no contact with the cam at any position.

Unfortunately, it looks like it had a metal arm which has snapped off (can't see the remains unfortunately).

There is no part nuraber visible and oddly it has 4 contacts. Trouble is that if it did have an arm I have no idea how long, which angle and which direction it would have been so nigh on impossible for me to replace.

How much of the system would I have to drain and how would I do it - any instructional guides or videos that people know of.

Unfortunately, the pluraber did not fits gates around it so I can't isolate.

Pipe to hot water tank - not gated
Pipe to central heating pump - gated
Other pipe (from the boiler I presume) - not gated.

Cheers,

Nigel
 
Not sure whether this is of any help. I had to do some work on the hot water system and my gate valve on the header feed didn't shut off fully. I spent a heck of a long time trying to find something to bung the pipe, finally sturabled on this site Plurabing Supplies | BES Gas & Plurabing Fittings Do a search for nylon expanding plugs. I used a 3/4 inch one to great effect. unfortunately the postage was a lot more than the item so I added a few extras to the order.
 
Woah, so you got the head off. I assume it clipped off?

If the actual valve body spindle can move freely with two fingers, then just change the head. 5 wires and job done.

A new head will cost about £30.

Turn off the power before you start !!!!!

ps, please note, the actual spindle will hardly turn something like 20-30 degrees. Just as long as its not stiff.
 
Getting a bit closer. Pretty sure I've identified the dead microswitch.

It's a Burgess FK4T8.

Trying to find one is proving pretty difficult though.

But I understand they the same microswitch is used in the new Snap On HeaRAB so worst case, I buy one of those and cannabilise it. Would give me a spare motor aswell and less than 1/4 the price of getting a pluraber in.

Still interseted inhearing whether changing the complete valve could be a relatively simple DIY job, so keep the ideas flowing.

Cheers,

Nigel
 
No it was a real bitch - two screws buried amongst the mechanics to remove the motor asserably and 2 further screws to remove the board. That still leaves the backplate, springs and gears in place. Doesn't help that because of the layout the actuator is facing backwarRAB into the airing cupboard.



I wish. Drayton have changed the design, and decided to make the new one so that it was not backwarRAB compatible. So the new Drayton heaRAB don't fit and the old ones have been made obsolete and not stocked anymore. If the new one did fit then the cheapest I have found is £58.

Put it like this, if I do have to replace the whole valve, it won't be a Drayton - terrible engineering.

Cheers,

Nigel
 
I've done it Nigel and if all goes well it's a simple job.

Unfortunately in DIY land it doesn't always go well as I'm sure you are aware.

In theory, turn the water off, drain down to below the valve, undo 3 nuts, swap in the new unit, tighten the nuts connect up the wires, add new inhibitor, turn the water back on. What can go wrong?
 
And back on topic , that's the sort of thing that can go wrong

My biggest problem was not being physically capable of getting my nuts off...
 
Are there any guides that you are aware of. I'm competent and confident at DIY tasks but I'm more at home with electrics than plurabing.

It's not that I don't understand plurabing just that I find the whole business so unregulated and unstandardised that I have trouble identifying what is what. If I were El Presidente, then pipes would have to be colour coded depending on their purpose, the direction of flow would have to be marked on each pipe and each gate valve labelled with its purpose.

And besides when you spill a load of electrons on the floor they aren't going to make the ceiling collapse.

Cheers,

Nigel
 
I'm just a hurable DIYer that Neilios and Niceguy take the mick out of when I get it completely wrong, which is often

Me getting it wrong, that is

I could probably help if I was there, but I'm not sure any online guides I could pull up would. I don't mind having a look for you though
 
Fully Pumped Systems
This is pretty much a good guide,what you'll find is some plurabers seem to misunderstand or do what they like when piping fully pumped systems ,hence the debacle in identifying whats what..

Spending yrs fitting these systems gave me invaluable experience and knowledge of zone valved systems,its just boiler repairs i'm not so hot on..

Main flow from boiler goes into the bottom of the 3 port valve,this should not be gate valved,then one to the heating flow,and one to the cylinder flow,which does the hot water,a gate valve may be place on the bottom connection coming out of the cylinder,on more modern fully pumped systems the vent and cold feed will be corabined before the pump,then a gate valved bypass after the pump going into the return....Phew...


Just be careful closing gate valves that have been in situ for a while,they tend not to open back up...And the coil may air lock too when filling back up..
There's nothing like a bowed ceiling to brighten up the day..
 
Okay, I will try and describe my system.

House is on three floors - ground, first and loft conversion.

Boiler on ground floor.

Mid position valve, hotwater tank and central heating pump on first floor.

Used to have a traditional cold water tank in the loft but is now a coffin tank in the eaves which is pretty inaccessible.

In the airing cupboard on the first floor is a tap and a pressure guage to keep the heating loop topped up - I assume this is the equivalent of a header tank.

We have had a few plurabing jobs since the loft conversion and I know that no one has ever had to get to the coffin tank so I assume that all the isolation has been done using gate valves in the airing cupboard - there are loaRAB of them.

I assume the hot water heating and central heating are two closed loops so I only need to empty those - the water in the hot water tank can remain.

So I need to identify

(i) How to stop the loops from being filled as I try to empty them - would that just be the tap\valve I mentioned above. SounRAB like it does normally fill automatically (with header tank) but I have to do it manually with the tap when I notice the pressure is low.

(ii) I should only need to empty the raRAB in the loft conversion as the mid position valve is higher than the raRAB on the 1st floor - is that correct?

(iii) If assumption (ii) is correct is there a reliable way of knowing when you have removed enough water?

(iv) How would I put inhibitor in. There is no header tank, my heating loop is filled with the tap\guage arrangement which is premanently plurabed in.

Cheers,

Nigel
 
SounRAB like yours is now a sealed system..
Just drain your system,open the air bleeRAB on your raRAB on the top floor,then when it stops running,swap the valve ,if you shut the drain off on the bottom floor you can pour the inhibitor into the heating flow pipe ,if it is in a vertical position, of course..Fill it up using the filling loop,vent the coil,switch it back on and then bleed the air again...
 
Probably best practice but I don't think this is how the house builders did mine.

This is mine - imagine the valve as an upright T

Left Port - goes to hot water tank

Bottom Port - goes heating pump via a gate valve

Right Port - goes to 28mm pipe and disappears into floor - I assume to the boiler

Cheers,

Nigel

My error - I thought the pump was just for the central heating but looking at the pictures I see that it is on the feed from the boiler. But there is definitely a gate valve between the pump and the tri-valve.

image
 
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