Motorised valve

[rotadays]

Hello,
I need to replace the 2 port motorised valve assembly on my heating system. The current motorised valve has the following id numbers 40003916-001, it is the six wired version, is this a V4043 I need ?

I have a heatrae sadia mega flow heating system with a Potterton pro max HE boiler.

Thanks in advance

 

[D_Hailsham]

How do you know you need to replace the valve, not something else?

 

[oldbuffer]

1. 40003916-001 is the Honeywell number for a replacement head for the V4043 motorised valve.
2. The V4043 comes in different sizes. You are likely to need either the V4043H1106 which is the 28mm compression version, This has the sixth (white) wire. (Measure the pipes into / out of it to see if 28mm or 22mm)
3. If the valve is attached to the Megaflow rather than the heating circuit, you need a G3 registered engineer to change it.
4. As D_Hailsham says, how do you know it needs replacing?

 

[rotadays]

How do you know you need to replace the valve, not something else?

Hello,
Thanks for replying.
As you have asked....
I have an intermittent fault with my boiler, it is not firing up in the morning with call for hot water so I had the boiler serviced hoping that may resolve the problem. I have since replaced the combustion chamber seal which was falling apart and partially missing, (read on a forum that can cause similar problems) , not mentioned incidentally by the service engineer.
The problem got worse, to the point where the boiler would not fire up at all, so I removed the motorised head, checked the gearbox a bit clunky so lubed it up seemed a lot smoother, that was about 4 weeks ago and the gearbox is still ok. I also checked the copper valve movement when the head was removed and it seemed a little stiff so I got the pliers on it opened and closed it for a minute or two and it seemed to loosen it up. Put it all back together boiler was firing up ok ,however it is still playing up, when the boiler will not fire up I can press the rest button on the boiler repeatedly and it won't fire up. As soon as I remove the motorised valve and replace it the boiler fires up ?
That is how I have come to the conclusion that it is the valve assembly. Thought I would try this and if the status quo remains I will call in an engineer.
Regards

 

[rotadays]

1. 40003916-001 is the Honeywell number for a replacement head for the V4043 motorised valve.
2. The V4043 comes in different sizes. You are likely to need either the V4043H1106 which is the 28mm compression version, This has the sixth (white) wire. (Measure the pipes into / out of it to see if 28mm or 22mm)
3. If the valve is attached to the Megaflow rather than the heating circuit, you need a G3 registered engineer to change it.
4. As D_Hailsham says, how do you know it needs replacing?

Thanks for getting back to me, interesting point about the motorised valve, as I have a six wired motorised head on 22mm copper pipe, this would suggest then that I have a 28mm motorised head six wired on 22mm copper pipe instead of the five wire. I am a little confused as the (sixth wire, white) is supposed to be electrically isolated, so does this mean it is not connected to any other part of the circuit?
Have attached some pictures which confirms the white /offwhite cable electrically isolated, not sure what you meant by the valve being attached to the Mega-Flow hope the pics clarify.
Really appreciate your time
Regards

 

[Agile]

If you have replaced the combustion chamber seal yourself then you do really need an engineer to check it and reset the combustion parameters. A DIYer should not have been even opening the sealed boiler case!

It does sound as if the motor valve is not operating the microswitch. Perhaps because the shaft is stiff or the ball is swollen.

You MIGHT find that putting a little silicone lubricant like WD40 on the shaft and repeatedly turning it could free it up and enable it to move further.

Rather than replace the whole valve body there used to be some partial kits available from BES.

Or the gear assembly in the head at be worn and just not operating the switch reliable. You can buy replacement heads. But My suspect would be the body!

If the valve supplies heating then you can work on it. But not if it supplies an unvented cylinder.

Tony

 

[rotadays]

If you have replaced the combustion chamber seal yourself then you do really need an engineer to check it and reset the combustion parameters. A DIYer should not have been even opening the sealed boiler case!

It does sound as if the motor valve is not operating the microswitch. Perhaps because the shaft is stiff or the ball is swollen.

You MIGHT find that putting a little silicone lubricant like WD40 on the shaft and repeatedly turning it could free it up and enable it to move further.

Rather than replace the whole valve body there used to be some partial kits available from BES.

Or the gear assembly in the head at be worn and just not operating the switch reliable. You can buy replacement heads. But My suspect would be the body!

If the valve supplies heating then you can work on it. But not if it supplies an unvented cylinder.

Tony

Thanks Tony
My suspicion was the micro switch on the motorised valve, I have already lubricated the shaft of the valve and it did appear to free it up.
With regards the combustion chamber I fully appreciate your comments but honestly I watched the guy servicing the boiler and the combustion chamber cover was easy to remove and refit but I was disappointed that he did not mention the fact the seal was almost completely gone. When I replaced it the seal was crumbling away, I fully cleaned all the surface and fitted the correct self adhesive seal. I am a reasonably intelligent person and a decent DIYer although I appreciate a little knowledge can be dangerous but when you call in a so called expert heating engineer to service your boiler and he doesn't mention a almost non existent damaged seal it does worry me.

I will replace the motorised valve assembly and if someone could now confirm if I need the 5 wire or 6 wired motorised head I would appreciate it immensely, I am assuming the 5 wired version has the same colours as the 6 wired version minus the white wire?

 

[Agile]

If the white wire is not connected then you don't need it.

But you may only need the body changed and your head may well be fine.

You can often get new bodies cheaply on Ebay as people buy whole valves and find they can get away with only using the head.

Anyone opening the combustion chamber should always replace the seal on virtually all boilers.

But that is not the main point. After opening the chamber the combustion parameters need to be checked and adjusted using a flue gas analyser which you are unlikely to have!

Tony

 

[rotadays]

If the white wire is not connected then you don't need it.

But you may only need the body changed and your head may well be fine.

You can often get new bodies cheaply on Ebay as people buy whole valves and find they can get away with only using the head.

Anyone opening the combustion chamber should always replace the seal on virtually all boilers.

But that is not the main point. After opening the chamber the combustion parameters need to be checked and adjusted using a flue gas analyser which you are unlikely to have!

Tony

Hi Tony
Once again thank you for the swift reply. Appreciate the info about the copper body assembly I will look as the motorised valve does look ok however when I priced them up there isn't a great deal of difference in price from a motorised valve and the complete assembly.
Can you confirm that my existing motorised valve with six wires would be exactly the same as the five wired version and the one I have fitted will therefore be ok?
Regards

 

[Agile]

The heads are the same apart from the extra wire.

I said buying from Ebay. From suppliers they are far more expensive. From a supplier you might as well buy the whole assembly.

On Ebay the body is often only £15 or so when sold by a DIYer. But you may not know if it is a genuine Honeywell or a copy!

 

[D_Hailsham]

The Honeywell valve in the pic above is on a pipe connected to the Megaflo; which answers oldbuffer's earlier question.

More importantly, the valve is part of the cylinder's safety system - necessary as it is an unvented cylinder - which must be repaired/replaced by an engineer with G3 qualification.

 

[rotadays]

The Honeywell valve in the pic above is on a pipe connected to the Megaflo; which answers oldbuffer's earlier question.

More importantly, the valve is part of the cylinder's safety system - necessary as it is an unvented cylinder - which must be repaired/replaced by an engineer with G3 qualification.

Appreciate your response.
The valve assembly is a straight swop, wiring like for like is simple, I have already drained the system three or four times as I have completely gutted and refurbished both the bathrooms and moved the location of old radiators and installed stainless steel towel radiators, refilled the system and added inhibitor.
What is the specific safety issue and difficulty in swapping these motorised valves ?

 

[Agile]

There is no difficulty.

Just that the Building Regulations say that anyone working on an unvented cylinder and it's controls must hold the G3 qualification

 

[denso13]

Just that the Building Regulations say that anyone working on an unvented cylinder and it's controls must hold the G3 qualification

It doesn't say that in the Building Regulations at all. It is mentioned elsewhere.

 

[ianmcd]

Anyone opening the combustion chamber should always replace the seal on virtually all boilers.

Absolute Absolute rubbish, where do you get this shoite from ???????