Replacing 3 port valve?

[mr_simonward]

Hi, I wondered if anyone could give me an idea of what would be involved in replacing a 3 Port Valve that feeds the hot water and central heating?
This would be my first attempt at any plumbing, but I am technically minded and not worried about the electrical work involved...

Secondly, what would I be looking to pay to have someone come in and look at it / fix it for me?

Background to the problem can be found here: http://www.diynot.com/forums/viewtopic.php?t=47159

Cheers Guys.

 

[chrishutt]

It's easy enough if you can drain down the system to the level of the valve.

 

[Moz]

mr_simonward

I would be wary about the building regs with new lecky guidelines ... Dont attempt it til you are told by a Electrician its ok

 

[jobloggs]

Chrishutt et al

What would be the pros & cons of putting isolating valves on the branches to HW and CH branches and using them plus a pump valve to isolate valve for removal/replacement.? After all pumps have isolating valves.

 

[chrishutt]

Excellent idea. That's what I do.

PS. Don't worry about building regs. Doubt whether many electricians will know about wiring a mid position valve anyway.

 

[scatmanjohn]

mr_simonward

I would be wary about the building regs with new lecky guidelines ... Dont attempt it til you are told by a Electrician its ok

I don't think there is any restriction on working on the actual central heating wiring and controls.

 

[MANDATE]

The problem with these valves are; either they dont move to the CH position or if they do they don't fire up the boiler due to a faulty micro switch. ( no power output on the orange wire)
Best idea is to remove actuator head off spindle and get someone to try HW only, HW and CH shared and then CH only while you watch the quadrant move to the various positions( that is after a few secs delay)
If it moves to CH and orange wire dead micro switch is the problem.
If it does not move to CH then motor maybe the fault. But make sure grey wire is live.
The white wire supplies power to drive motor from HW to HW/CH and then the grey wire supplies power to take over the last half of the movement and hold the valve at the CH position.
If the valve spindle is free there is no need to change valve, why not just change the head. Although I believe a valve with head is not much difference in cost that a head.

 

[scatmanjohn]

The problem with these valves are; either they dont move to the CH position or if they do they don't fire up the boiler due to a faulty micro switch. ( no power output on the orange wire)
Best idea is to remove actuator head off spindle and get someone to try HW only, HW and CH shared and then CH only while you watch the quadrant move to the various positions( that is after a few secs delay)
If it moves to CH and orange wire dead micro switch is the problem.
If it does not move to CH then motor maybe the fault. But make sure grey wire is live.
The white wire supplies power to drive motor from HW to HW/CH and then the grey wire supplies power to take over the last half of the movement and hold the valve at the CH position.
If the valve spindle is free there is no need to change valve, why not just change the head. Although I believe a valve with head is not much difference in cost that a head.

I don't think you can take the head of that one, (ACL i think) The newer ones are removable.

 

[gasmarkone]

Simon, sorry I didn't follow up the original thread [ don't stay up that late anymore!]. The point I was making about the room stat is that model only clicks if it has power to it, so you could have proved the timer CH output without a multimeter. Looks like you'll have to drain system [I would 'bung' it, can only take half hour] to change valve. Good luck, not too bad a job, keep posting & we'll get you there! Look forwards to the 'my rads won't fill thread[blocked cold feed], rads aren't hot [ air?], my kitchen ceiling has gone droopy [ go over to building]. Just joking, hope all goes well

Mark

Milk, no sugar ta.

 

[ollski]

No you can't remove the head on these without destroying them and you couldn't get a replacement anyway, the new ones have a little lever you push and they come straight off. Probably better to fit a drayton 3 port as you can utilise the existing compression fittings and olives. Honeywells are beeter valves but you will need to remove the old olives and nuts and replace as they are a different thread size. If you are feeling confident why not treat yourself to a rad bung kit so you don't have to drain it down?. With regards to the isolating valves, if you are going to fit extra valves then make sure they are top quality ballofix otherwise they will be a leak waiting to happen or a waste of effort that will never work and be prepared for the extra wonga on the parts cost.

 

[mr_simonward]

Cheers for all the advice guys. I'm not sure if I want to have a crack at this though and was considering giving a guy in our village listed in yellow pages as "Central Heating Services - Domestic" a ring.

What should I be expecting to pay if I were to get someone to do this for me?