Replacing a 3 port valve

[Jever]

Hi,

I'm having problems with my heating system and identified that the source is a faulty 3 port valve. It's a fairly old system (installed 1986) and the 3 port valve is a Honeywell V4073A1062. It seems that it's one of the older models and requires a system draindown if you want to separate the box with the motor in from the pipework.

Before I try to replace anything, I'd like to make sure I know exactly which part has gone wrong to minimise the work.

Am I right in thinking that either the motor or the valve (the bit in the pipework?) may be broken? If so, how do I tell which has part is broken? If it's any help, there is no longer any tension in the lever on the side of the box - its moves up and down freely by hand.

Also, are the replacement parts easy to get?

Thanks in advance for any help.

Jever

 

[footprints]

If you have the old one you need to exchange the whole valve complete.
The old heads have different fixings for the head and from what you say chances are the body is the bit that's jambed anyway.

A tip is to cut the wires (after isolating of course ) off at the wiring centre or junction box on the system and just leave a couple of inches of wire in the terminal as a marker. You can then switch each wire for the short bit you left one at a time, much easier than trying to work from diagrams and ripping them all out at once. Oh and as belt and braces take a photo of the wiring before hand.

 

[45yearsagasman]

Why not tell us the symptoms you're getting? The lever on the side does not give indication as to what may be wrong in most instances.

 

[Jever]

Hmm,

It sounds like I will have to order one of these:

http://www.amazon.co.uk/Honeywell-V4073A1062-Motorised-Mid-Position-Diverter/dp/B00BJ74N9C

rather than just replacing with one of these:

http://www.plumbcenter.co.uk/en/hea...ll-40002737-003-synchronised-motor-240v-10896

Have I understood that correctly, footprints? I like your tip with the wire, by the way.

The only symptoms I can give are that regardless of whether I switch the heating, hot water or both on, all I get is heating, which suggests to me that the port valve is stuck on that setting/position. If I turn the heating or water on, the boiler fires up, but there is absolutely no sign of life in the valve.

Is there anything else I should be looking out for?

TIA

Jever

 

[footprints]

Afraid it's the whole valve you need, (terrible price aren't they!) if the valve is in the open position cutting the power to the valve should cause it to return and some resistance on the lever, but when stuck it remains there.

A faulty motor normally means the valve remains in the hw only position.

I have (with power off!) opened up the top cover and managed release the spindle as a temp fix for customers but it will fail again quickly.

Given the age of the part anything other than replacement will be a waste of time in my opinion.

 

[Jever]

Hi,

Thanks footprints, I've ordered the whole unit and hope to pick it up in a couple of days.

Apparently the input/output ports to the unit are 1 inch BSP female connections. The faulty unit that is currently installed to my system has brass female ports that then appear to have brass female to male adapters, which then connect to the copper pipework with what looks like a giant 'tap connector' fitting' (i.e. a brass nut on copper pipe, probably with a fibre washer).

I intend to take the unit out and reuse the other fittings (brass female to male adapters and brass to copper fittings), but what worries me is that I've not made any brass to brass connections before and there appears to be a brown jointing compound. Can I just clean off the old compound and reuse? If so, what compound would you use to make the joints? Is ptfe tape a bad idea here?

Thanks in advance

Jever

 

[footprints]

Any chance of a photo? All sounds quite odd to find 28mm on an ordinary domestic system and union adaptors too. Are you sure they are not 22mm female compression with the male nuts?
Brass to brass screwed connections are fine with ptfe but use lots it goes down to nothing when compressed.

 

[Jever]

Hi,

Sure. I'm new to uploading here, but hope I've managed to attach the picture.

If it's any help, I've ordered the replacement from these people:

http://havelockcontrols.co.uk/itemdetl.php?itemprcd=53211052

which also shows the specification of the inlet/outlets.

Jever

Untitled

• Jever
• 15 Oct 2013
• 1

 

[footprints]

I'm a bit confused the pipe on the right is smaller than the one on the left and has had an adaptor to a copper to iron compression union fitted is that 15mm or 22mm?

If it is 22mm that makes the one on the left 28mm quite possible but it would take a superman to put the bend in it that it has got so I'm a bit unsure if it is a 3/4 or 1" valve.

Check the sizes to see, but if the 1" valve is on it's way there is not much you can do till it comes.

The brown stuff is Hemp and jointing paste (Boss White) ptfe is the modern replacement and will work fine.

Old Imperial sizes were internal diameter so an old 3/4" iron pipe thread is around 1" external diameter, easy to confuse the sizes.

 

[Jever]

Hi,

Yes, you're right, the copper pipe on the left is 28mm, whilst the copper pipe on the right is 22mm. I've added a picture of the bend on the 28mm pipe from a straight-on angle, just in case the top view is a bit misleading.

I've also added a picture from the top that includes the pipe to the inlet port. In summary, it's 28mm copper pipe in and then 28mm out to the immersion and 22mm out to the CH.

As you say, there aren't really any problems I can solve until I've got the new valve and start work.

However, thinking ahead and assuming that the brass casing of the valve has the same external dimensions as the old one, it should be a straight like-for-like swap with no significant changes to the pipework. I think that the right hand port and the inlet at the top of the photo can be tightened up so that the new valve is in exactly the same position as the old one, but I am concerned that the left hand joint (which I think I'll have to do first) may tighten up leaving the valve in a different position, which means I'll have to adapt the 28mm pipework.

Have I read this correctly?

By the way, thanks very much for your insights so far, it's very good for my confidence as I've not tackled this sort of problem before.

Jever

Untitled

• Jever
• 15 Oct 2013
• 1

Untitled

• Jever
• 15 Oct 2013
• 1

 

[footprints]

Yes the other photo shows the set on the 28mm has been done with a bending machine, I wonder if it was an old gravity system that was converted, still no matter

As you say you will need to get the LH elbow connection on and correct first.
You may have to have several goes to get it tightening up in the right position just add more ptfe each time till you get it right.

The old hemp was good for that as it had more "body" but persevere with ptfe it should be fine, if all else fails get some Loctite 55 cord.

http://www.tooled-up.com/product/lo...oductlisting&gclid=CNqE--6YmboCFY7HtAodQF0ApQ

That has a bit more substance if needed.

The other joints look like they will have olives, rather than washers a bit of ptfe over the olive will help the seal on the old joint when you remake it, or you can push the boat out and get a tube of Fernox LSX sealant to smear on them brilliant stuff, I love it! Never let me down yet but pricy for just one joint or two.

http://www.screwfix.com/p/fernox-ls-x-leak-sealer/23614

Good luck, fingers crossed it looks pretty straightforward as long as the old joints come apart without too much effort, whatever you do don't pull the connection on the cylinder about too much that is the weakest part of the set up.

 

[Jever]

Hi,

I've finally found time to replace the three port valve. Having drained down the system and carefully plumbed and wired in the valve, I now need to refill the system.

I've untied the ball cock in the f/e tank, which is now about half full. The downstairs radiators are full, but the upstairs radiators aren't filling up, even if I turn the heating on. The pump whirs and gets hot, but there's definitely no hot water anywhere.

I assume I have an airlock problem, but am not sure.

Would be grateful for any pointers.

Jever

 

[Hugh Jaleak]

On the side of the valve there should be a small lever, sitting in a slot. (Just visible on your pics, same side as the cable.)

Move this to the manual position, should notice slight resistance as you do so, and the valve will 'whirr'. (You are pulling it open against the springs). Once across there is an indent to lock the lever into position as it should try to return to it's default position under spring return. This will hold the valve open to both HW and CH ports to allow filling of the system. Hopefully you'll hear some gurgling as trapped air is released and system continues to fill.

 

[Jever]

Hi,

The electric motor was quite warm, so I unscrewed it from the brass valve casing and turned the spindle by hand, switched both the heating and hot water on, but still no movement.

Can it be right that the valve takes less than 1/8 of a turn for all three options, or is there a problem with the valve?

Bad time of year for this sort of problem!

 

[Armo74]

Did you clean out your feed and expansion tank before draining the system? If not some sludge deposits from the bottom of the tank may have made its way down the cold feed and created a blockage.
You can test this by holding a magnet where the cold feed tee's into the flow pipe from the boiler, if there is a blockage the magnet should be drawn to the pipework.