Buzzing valve on water tank

13 Aug 2012
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United Kingdom
Hi all

The valve on the pipework to my water tank is hot and making a buzzing noise. Is there anything I can do to stop it - I assume that it is a problem. If not - can it wait, or do I need to get a plumber out asap? I've taken a quick video, here:

Any advice gratefully received! Thanks
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1. Sounds like the gearing on the motorised valve has gone / is going.
2. You need to replace either:
2a. The whole valve, which requires isolating the water / draining down. OR
2b. The valve actuator, which includes the motor and gearing. No drain down required, provided the valve has a replaceable actuator.
3. I can't see from the video what make / model the motorised valve is. If you can let us know or provide a readable photograph of the valve, we can advise further.
4. It needs to be done sooner rather than later.
1. If it is an ESI you should be able to change the actuator.
2. Check the exact model number from the top of the valve.
3. Either buy the actuator kit or a whole new valve (which might be cheaper!).
4. Download the instructions.
5. Swap the actuator. This will require:
5a. Making sure there is no power to the boiler or to the valve. If in doubt, switch off at the main consumer unit switch.
5b. Remove the old actuator and install the new.
5c. At the wiring centre (other end of leads from old valve) cut through the coloured wires from the old valve, leaving about an inch of the coloured part still secured in the box.
5d. One by one, remove each old wire and replace with the new one, colour for colour.
5e. Put back wiring centre cover, reconnect power and all should be well.
6. If you do get a whole new valve, remove the actuator and use it. If you replace the entire valve you will need to isolate the water, and probably drain the system down.
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Thanks all. Here is the valve itself. It was installed when the central heating was installed, about 5 years ago. There are 4 of them (hot water, and the three zones on the heating system). One of them has already been replaced - the plumber who did that was pretty critical of the original installer for not using honeywell, and when we had some more work done recently another plumber said the same thing. Oldbuffer - many thanks for the instructions. I have a plumber coming around anyway next week - can this wait until then, or is that like asking for the length of a piece of string? Thanks again.

Screenshot 2020-12-30 at 19.28.49.png
Nothing wrong with not using Honeywell, they may just not last as long. Esi are supposed to be good, haven’t dealt with them personally.
Good to know, thanks Chris. We've had a fair bit of trouble with them and the other plumbers who looked at them were pretty critical (if this one needs replacing that is 50% of them within 5 years, and we've had a few other issues too). But I have no insight beyond that - I may just have been unlucky!

On to the job at hand. So the valve is an ES ZV 222L, which I think means I need one of these:

Annoyingly the link to download the instructions on the ESI website doesn't seem to work ( but I assume there will be an old fashioned paper copy in the box!
Thanks both!

I took off the cover. I needed gloves, it's very hot!

Here is the motor.




I'd never heard of a synchron motor until today. I am no expert but the specs I can see are 50hz; 5W and 4RPM. I have no idea how important it is to match exactly. I've had a quick look at where I might go in the morning to find a replacement. Screwfix has one, but it is 5RPM (and 4.5W). Toolstation has three: the Corgi one is 5RPM and 6w; the Drayton one is the one stocked at Screwfix; and the honeywell one is 6W (can't see RPM). City Plumbing has a few: a 6W 5RPM one; a Boss one that is 4RPM, but 6W; and a "Universal" one that I can find no technical details for.

Would any of these do, or do I need to find one that is 4RPM and 5W?

Also - I left it locked open so we have hot water, rather than rely on immersion (although it still makes a really loud buzzing sound). Good idea? Bad idea? doesn't matter? Thanks!

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The screwfix one is a genuine Synchron motor. A lot of the cheaper ones have nylon gearing that fails prematurely in the hot environment. I don't think you need to worry about the difference between 5 and 6 RPM. The important dimension will be the depth of the drive spigot, some are longer than others. To change the motor, put the valve in the manual position, undo the flange screws and rotate the motor slightly whilst withdrawing it. Cut the wires close to the motor and use the connectors supplied with the new motor. The screwfix/drayton motor will have spades that you need to cut off.
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Cheers. I got the screwfix one and installed it. I'm not really sure how to tell whether it is working properly. If my shower is cold in the morning then I guess it isn't! All I could think to do to test it was to turn off the hot water on the wall box and test the resistance on the little lever on the valve. When the hot water is off the lever is really stiff; when I turn the hot water on it becomes really slack. Which I think means it is working fine. It is still very hot, but blissfully quiet. Thanks for your help everyone!
Thanks. I've finished the kids baths now and we had hot water, so seemingly all is well. Thanks to everyone for the guidance: I was looking for a diagnosis rather than how to DIY the fix, but it's great that people are willing to talk me through it. The point about cutting off the spades on the new unit for example is really specific and helpful; and the step-by-step on swapping out the entire actuator was also super-helpful. I paid to have the entire valve replaced last time this happened - this was a lot faster and cheaper!

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