Boiler problem: Heating OFF, water ON

It looks like there are different replacement heads for the different valves. The one listed for the 4073A is 4000-3916-003 For the 4043A it is ****-001 and ****-002 for the V4044. So it looks as if you have got hold of the wrong part and you need a 4000-3916-003.

Around =A353 from here (no connection) if you can't get from Plumb Center

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Reply to
JohnW
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I'm afraid you've got the wrong head! You *need* all five wires - otherwise it won't work. Sounds like they've given you a head for a diverter valve rather than a mid-position valve.

Reply to
Roger Mills

Yes, Roger, also as JohnW also remarked, and I myself had already remarked in a post immediately following the one you quote above.

Pursuing the Honeywell V4073A valve across the internet, I discovered that the uk.plumbing.com site offers a PDF from Honeywell which makes it clear that they do FIVE models of the 4000-3916 head.

The PDF states that for a V4073 I need a 4000-3916-003 not a

4000-3916-002. (I'm beginning to sound like some kind of 3-way-valve spotter here.)

HOWEVER I can be forgiven for getting the wrong head, for HERE is the label that is stuck on the back of my valve:

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which head module would you buy if you had that label on your old valve?!

FORTUNATELY, I have now got a 4000-3916-003 (from my local Plumb Centre branch: *excellent* friendly service); it cost 77 pounds, but given that I've been down twice this morning, replacing a mis-ordered part and getting the right part, that's a price I'm happy to pay!

I've fitted it! (With a little side adventure in CAREFULLY putting all five wires into the rat's nest at

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and then finding that I had not threaded the main cable round the pipes the correct way...).

I've switched it on!

AND THE HEATING SEEMS TO WORK!!!!!

And so, I hope, ends this particular saga. Thanks to numerous folks in D-I-Y, but in particular JohnR and RogerM, with their unfailing encouragement!!!

Remember: this started out with me thinking that our very sophisticated boiler had gone wrong: thanks to D-I-Y I was quickly disabused of that.

Postscript: Coincidentally(?) Glow-worm/Homeserve rang me yesterday with an offer to insure us until the end of January for ONE pound. Sounds great, but I refused it, ever suspicious. Had I taken it up, I would now be in mid-nightmare: I would have waited for them to come out; they may - or may not - have diagnosed the problem right away; having diagnosed the problem, they would then tell me that they didn't cover non-boiler parts; assuming that they would nonetheless go ahead and fix it ... well at best they'd have got the wrong part to start with, as I did!

Cheers and thanks again -- here's hoping I won't be starting a new heating thread for a while...fingers crossed.

John

Reply to
Another John

Hi John

It's David J from the 'other thread' (sluggish actuator)

You are ahead of me in your problem resolution. as I have only today removed my Myson 322 actuator cover to investigate. I have been closely following your thread though.

I did Elecrical Engineering... but I still get foxed by domestic wiring sometimes....

My spindle was rather stiff at first. Too tight for my fingers to turn - but a dash of '3 in 1' has now really loosened it up. However, (unlike yours) there are no stops on my 3-way valve. It rotates through 360 deg.

I didn't remove any power. I simply removed 2 screws and pulled the actuator cover away from the D-shaped valve spindle.

The online Myson installation data sheet says 'set the lever to MID when installing'. However my lever would not move away from AUTO. I know it did before the actuator was removed.

After reinstalling the actuator onto the valve spindle correctly, I switched on the CH from the room thermostat and the CH led came on, and the manual lever is loose again. (confusing, that)

I am hoping that I have now removed the 'stick-shun' that was affecting my system. Your problem seems quite different imho....

David

Reply to
David J

Yes, fell into my own trap there - I was assuming the call for heat from the orange wire on the valve would be there to keep it running.

(I think this is the electrical equal of emptying the bucket of sludge cleared from a U bend into the sink above!)

Setting the cylinder stat higher than the flow temperature of the boiler ought to do it though. (but take care - the hot water will be dangerously hot!)

Reply to
John Rumm

The three wire version would make the valve a three way diversion valve rather than a mid position one. I assume the wet side is exactly the same for either, so the label on it is not exactly wrong - just incomplete. (we are also assuming that someone has not upgraded the works at some point in the past).

The diversion valve only allows for HW or CH but not both at once. The HW has priority, and you can only get CH once the water is hot enough.

Reply to
John Rumm

Bit like our piccie:

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Reply to
John Rumm

re your point about the label on my unit, John(R):

No no (with respect): the label *states* that this is a V4073A... "For head replacement use 4000-3916-002" see

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However the Honeywell data sheet for their 40003916 heads specifies 002 for the "V4044 series 3-port diverter valves" and 003 for the "V4073 series 3-port mid-position valves".

(The Honeywell data sheet, which is refreshingly neat and authoritative, is at

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I still reckon I made an innocent mistake, explicitlu misguided by the label on my unit!

All's well that ends well though. (if it has ended...)

Thanks yet again! John

Reply to
Another John

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