Faulty zone valve (Link to video enclosed)

[Mathew Newton]

I've got a Siemens CSV222 2-port zone valve which is making a clicking sound when closing. Functionally it seems to work fine, however I am wondering if the noise is indicitive of impending failure or some other issue. Furthermore, the noise can be annoying as the valve is in the airing cupboard above the lounge and can be quite noticable (to me at least; noone else seems to hear it!).

Here's a video of the valve opening and closing (and clicking as it does the latter):

(Who says YouTube's full of cr@p?!)

I'm wondering if the momentum of the servo caused by the spring-loaded closure is causing the gearing to jump instead of stopping dead...?

Is this normal and/or something I can do something about? We've only recently moved in so have little to compare it to.

Mathew

[Allan Mac]

YES worn teeth somewhere.

You can normally buy the motor head without the whole valve. Cheaper and no draining down.

Allan

[Mathew Newton]

You were right:

first few teeth of the valve arm had been worn away. Presumably it is only a matter of time until there's nothing for the motor to grip to start the valve opening?

I can pick up a new valve off eBay for =A320 (retail =A340, and =A330 for just the actuator) but something tells me it's likely to happen again as the plastic arm is clearly an achiles heel. Will other actuators fit this valve, perhaps it is possible to tell by this picture of the valve body?

[Allan Mac]

Yes it will fail sooner or later. I've seen most common makes of valve and that does'nt look like any of them. Make sure the valve spindle is'nt tight before you decide what to replace. They do tend to have a fairly high failure rate. (all makes).

Al

[Mathew Newton]

I've decided that Siemens is not worth my money given their valve only lasted 4 years so I'm going to go for a Honeywell V4043. The valve length is 112mm - exactly the same as my Siemens so should hopefully be an easy slot in.

However, the datasheet for the Honeywell

says: 'NOTE: Continuous operation of the valve motor at the fully open position is not recommended' - what does this mean? If I, say, have the heating on for

15 hours at a time in the middle of winter, with the stat constantly calling for heat, does this count as continuous? It's not a warning I'm seeing on other valves...

Mathew

[Allan Mac]

What a strange comment! I can only asume they mean months rather than days. This seems to be one of the most reliable makes.

Al

[Roger Mills]

It should be ok size-wise, but check that the compression nuts have the same thread. ISTR that Honewell use finer threads than some of the other makes. If they *are* different, you'll have to carefully remove the olives and existing nuts from the pipes, and re-make the joints.

The motor runs stalled when the valve is open, so maybe it doesn't like doing it for *too* long without a break. In practice, it would be unusual for a stat to be calling for heat for 15 hours continuously - unless the heating system was grossly under-powered.

I've been using 3 Honeywell valves (HW + 2 heating zones)for several years without a problem.

[Mathew Newton]

Ah bugger it... I thought it was all sounding too good to be true! What you say does ring a bell - I'm sure I've read elsewhere about the thread pitch issue.

I might just stick with replacing the actuator with another Siemens (whole valve and just swapping the actuator). At least then I'll have a few spare parts should any other aspect of it fail at a later date.

Mathew