CH motorised valve replacement

[Vic]

My CH has 2 motorised valves. They are 20 year old Honeywell V4043H two-port valves with 22mm compression fittings. They both have had the motor/actuator part replaced at least once in that period. One of them has gone again and I'm sure the other is not far behind.

Having looked at the prices on Ebay, a replacement valve is going to cost me about £35. Curiously, buying a replacement actuator on its own seems to be even more expensive.

What I do not like about this type of valve is that in the activated or open position, the motor runs continuously, which means it gets quite hot and evetually fails, or the brass gears wear out.

Rather than replacing with the same unit, would I be better getting something newer ? Surely some progress must have been made in the last 20 years. I don't mind paying a bit more. Are there better valves available now ?

Whatever I get, I would like it to be 22mm fitting, so that I could just do a straight swap. The space is tight and access is difficult, so I'd like to keep the plumbing work as simple as possible.

Any advice, anyone ?

T.I.A.

[Dave Liquorice]

I don't think the design of the V4043 has changed in over 20 years. They work and work reliably. A motor change or even two on each valve in 20 years, seems pretty damn good to me.

The motor doesn't run once it reaches the end stop it is stalled. They are only small synchronous motors so it's not a great problem. It'll get hot from heat conduction from circulating water anyway... I have four of them here all about 10 years old, only one has ever given any trouble.

[AlanD]

I also have 4 here, somewhat younger at ~4.5 years old, but no issues with any of them. If they all get to 20 years with only a replacement motor each, I'll be very happy.

[Roger Mills]

As others have said, the motors don't *run* continuously. They are

*powered* continuously when there is a demand for heating, and simply stall when the valve reaches the fully open position. They are *designed* to do this, and have a useful life of many years.

They are very simply, with little to go wrong - opening when a voltage is applied and closing, under spring pressure, when it is removed.

There *are* valves which are motored in both directions, and which remove the power at the end of an opening or closing operation. But the electrics to drive these needs to be a lot more complicated - so you can't do a straight swop with a 'conventional' valve. And the extra complication may well mean that they are less reliable - but I don't have any direct evidence of this.

[Vic]

On the one that I took apart a while ago, when the motor got to the end of its travel (i.e. valve open) the gear teeth somehow seemed to disengage, so that the motor kept turning. When power was removed the spring pulled it back. I guess what could have happened is that the teeth on the gear attached to the valve body had worn away at the end of its travel, so that they no longer engaged with the gear on the motor shaft, thus allowing the motor to keep turning.

Anyway, good should about a replacement. I was just thinking that 8 to 10 years service is really quite good, and worth investing in a replacement actuator. I'll go and order a couple. There are certainly plenty available.

Thanks for the reply.

[Vic]

Thanks for the replies. They all confirm what I sort of suspected from the start. I'll just stick with the 4043 and get a new actuator for it. In fact, I'll just buy the whole valve, as it's cheaper, and keep the body as spare.

As I mentioned in one of my other replies, on the valve that I examined some time ago, the motor just kep on turning, but I think it was probably due to worn teeth on the gears at the end of their travel.

Cheers.

[Steve Walker]

It's more normal for just the motor inside the head to fail. Replacement motors can be bought from Screwfix for about a tenner. I've replaced two out of nine in nine years (yes that is right nine valves! Each of our zones is a single room and the hot water tank is another, allowing independent control of times and temperatures).

SteveW

[dennis]

I have five valves and the system has been running for 30 years. All have failed over that time..

One the valve shaft broke/corroded through (new valve needed). The motors stopped working in two ( new motor in one, motor out of old actuator in the other). The micro switch stopped working on one (about 35p from Maplin). One developed a leak The others just became too sticky to close, even after I made the spring shorter and lubricated them.

[Graham.]

valves with 22mm compression fittings. They both have

has gone again and I'm sure the other is not far

about £35. Curiously, buying a replacement actuator

position, the motor runs continuously, which means it

newer ? Surely some progress must have been made in

available now ?

straight swap. The space is tight and access is

[<me9]

A straight swap can be difficult unless identical types. I've found 3 different thread sizes on 22mm zone valves. If different threads, removing the olives is required which can be fiddly and time consuming in confined spaces.

[Onetap]

There are Mo-MO (motor on, motor off) valves & actuators available, but SFAIK the only make available for domestic installations in Sunvic and their actuators are unreliable.

No, Honeywell is probably the most reliable domestic make.