Noisy radiator thermostat valves

[DaveP]

I have 6 TRVs, all now with Drayton Wiser radiator thermostats. Four of the valves so far have exhibited a whining noise, some worse and more frequent than others, the worst being the lounge where I am most of the time, shown in video attached.

Initially I thought it was the motor, but it continues if I take the batteries out. When it does it, if I unscrew the cap on the valve about half turn it stops, for a while. The cap doesn't move once done and it will happen again after a while. I've spent quite a while recalibrating them to see if that helps but it doesn't sort it permanently. It does it whilst heating up, down or holding temperature. I have 3 different make of TRV, and it's not 1 specific type, some are 28mm with adapter, but it happens on them and 30mm.
From my research it seems as though it could be the flow of water through the valve BUT it never did it on any with the manual TRV  heads, and I can't get it to do it with a manual one now. So, is it the flow, or something within the Drayton valve mechanism?
Any ideas and/or fix welcome 🙂

[david101]

Can I clarify, is the issue is with the valve body or the valve head?

If its the valve body have the valves been installed the correct way round or are they bi-directional?

[DaveP]

As I say above, all of the radiator valves were there and working with manual valve heads, just replaced them with the Draytons and I can't get it to do it with the manual heads, but somebody may know some good reason for that

[david101]

Manual TRV heads work differently to Wiser smart TRV's.  At least my Honeywell manual TRV's do.  A manual head, IME, will push down on the valve body pin to a lesser or greater amount depending on the setting where as I believe the Wiser TRV's start fully open.

[DaveP]

I believe they work the same but use a motor to push the actuator that pushes the pin in the valve. Why would they fully open, it would waste the battery, and I've not heard them fully open and why would that cause the noise I've described?

[david101]

 If the valve body is on the wrong way round, i.e the flow is in the opposite direction (doesnt apply to bi directional valves), then the valve body can make a noise.

[DaveP]

I assume by the wrong way you mean on return rather than flow?
But, as explained above, they're not new valves and it didn't do it before putting the Drayton heads on?

[PhilHornby]

My guess, is that it's some sort of resonance. The pin in the TRV body is maybe just lightly touching the actuator motor - whereas with the original TRV head, there was always the weight (18g or so) of the actuator 'cylinder' resting on the pin (even if it wasn't pushing hard against the plastic casing).

Perhaps the pump speed is too high and is helping  generate this effect?

Can you reproduce it with the TRV Head off, by manipulating the actuator pin?

[DaveP]

Thanks for the response, I almost used the word resonance in my description of the problem, but it didn't make the final cut!

I think you're right, but with the valve head off altogether I don't think there's anything to resonate with, unless you think it's between the valve's pin and internal mechanism. I've tried putting a manual head back on and making minute adjustment but cannot replicate it, perhaps the Drayton head actuator backs off just that little bit more.

I'm surprised nobody else has replied that they've had the same issue.

If by pump speed you mean the boiler, I don't believe there's any control over that, and it didn't do it with the manual valves.

Of course, when it gets warmer and the valve is closed more, it may not react the same!

[david101]

A simple check is to just make sure the valve bodies have all been installed correctly. Can the OP confirm this so that is one potential issue out of the way. Check that the flow through the valve body is in the direction of the arrow.

[PhilHornby]

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@DaveP wrote:

If by pump speed you mean the boiler, I don't believe there's any control over that, and it didn't do it with the manual valves.

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The pump will probably have its own control - rather than being done from the boiler. It's supposed to be set to give a particular temperature drop across the boiler...

...the one in my house was set to maximum; it's now set to minimum, with the variable-flow feature enabled!

I've recently 'balanced' all 17 radiators and the Wiser system came in very handy for doing this.

In a nutshell, 'balancing' involves setting the flow-rate through radiators, so they are all the same. There are billions of youtube videos telling you 'how' to do it, but I only found one, where a professional tried to show the process from start to finish (he failed!). You're supposed to measure the temperature drop across the radiator and adjust the lockshield until a particular temperature drop is achieved.

I bought a dedicated meter with two clip-on thermocouples and got exactly the same results as all my previous attempts over the years (in a different house). Basically, as the water from the boiler warms up, so the differential temperature increases - you'd somehow need to keep that flow temperature constant. A modern gas boiler might be able to do this, but my Oil boiler certainly can't. In the end, I adjusted each radiator in turn, so that the return temperature (at the boiler) hit the same value when the flow-limiting stat. triggered. I then used Wiser to open all the other valves - with the flow-stat set to minimum, which dissipated all the heat in the system. By having the same starting point for each radiator, I'm now happy that they're all behaving the same (even if they're all wrong 🤔).

The huge 'portrait mode' radiator in the kitchen now finally gets warm!

[DaveP]

The pipe coming into the TRV is hotter than the other end in every case, so I guess that's a yes

[DaveP]

I did research balancing and understand the flow and return temperature differentials and considered getting a meter/thermocouples etc. but the expense outweighed my interest for what will probably be a one off on a small system of 6 radiators in a small 2 bed semi.
Am I reading what you say above correctly, in that I could open all of the lock shield valves fully, then back 1/4 turn ;-), and use the TRVs to balance them? I checked the one in the lounge was fully open as I wasn't sure it was putting out as much heat as it could, and it was.

There is no external pump, and my new Baxi 830 Combi has separate heat controls for heating and hot water, heating currently set at 60 to ensure it condenses, though I want it lower when the weather gets better. The boiler and the Drayton hub are both Opentherm, and I even ran the cable when the boiler was replaced BUT wanted to get the boiler and Drayton controls proven first and with the Opentherm it disables the manual heat control. My research suggests that the Baxi modulation isn't great and someone said theirs is going up to 90, then dropping low and using loads more gas as it isn't condensing, the total opposite of what it is meant to achieve! Once I'm happy with it I might give it a try, and just swap it back if it doesn't work.

[PhilHornby]

I played your video to my other-half and guess what - she's heard one or more of our valves do it! (Personally, I'm as deaf as a post at the minute - apparently, there's a local, visiting Nurse Gladys-Emanuel who will come to the house to syringe out ears!)

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@DaveP wrote:

Am I reading what you say above correctly, in that I could open all of the lock shield valves fully, then back 1/4 turn ;-), and use the TRVs to balance them?

No - the lockshield at the other end is used to throttle the flow.

I checked the one in the lounge was fully open as I wasn't sure it was putting out as much heat as it could, and it was.

I think lockshield valves are supplied fully-open when new. All seven of my downstairs radiators were fully-open. This is in keeping with the rest of the system - I don't think it was ever actually commissioned. (Pump on max., no corrosion inhibitor, auto-bleed valves locked down tight, Bypass valve on default etc. It would only maintain pressure for 3 days at a time, when we moved in 😮. Nothing a meddling DIYer couldn't sort out 😉)

There is no external pump,

My pump is also housed within the boiler casing - but it's a discrete Grundfos UPS2 with controls (well a button!) on the actual pump. I went looking for information on setting up the Baxi 830 pump and found nothing at all (including in the installation manual ☹️) 

[DaveP]

That's quite funny about the valve noise, pardon!

I knew lock shield valves are used to throttle it, but thought maybe the TRV could do it dynamically.

The Baxi info is pretty poor, I search and look at forums and YouTube, that said, many of the "expert" videos are appalling. It's a bit worrying when I know more than some of these "plumbers" on the forum!

[Fozzie1960]

Have you watched this one,

https://youtu.be/7NsZ2d2Oups

[david101]

The problem with balancing radiators is that as soon as the TRV starts to close it messes up the balancing. This is why some manufacturers, Drayton for example, now recommend auto balancing valves with TRV's.

[DaveP]

I have now, thanks

[PhilHornby]

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@david101 wrote:

The problem with balancing radiators is that as soon as the TRV starts to close it messes up the balancing.

The flow rate is supposedly proportional to the temperature differential across the radiator (which makes sense). It also makes sense that you should have the same flow rate through all parts of the system - especially for those early-morning starts, when everything is on at once. Particular flow rates are the ones used by the radiator manufacturers to compute the heat output of any given radiator.

The problem I've always had, is in trying to get a stable differential temperature - with even one radiator, let alone when trying to go round adjusting them all in turn.

What I did, was use the Wiser Boost feature to open all the valves, so that the pump could circulate the residual heat (with the boiler flow stat on min.). Once it dropped to my starting point (40°C ish), I cancelled the 'boost', thus closing all the valves, reset the flow stat and opened just one radiator valve. I then adjusted its Lockshield until the return temperature was about 55°C, at the point where the flow stat turned off the boiler.

I measured the flow and return temperatures at the boiler - thus compensating for the pipe work to each radiator as well. At no point was any measured temperature stable - but the rate of change is now identical when any given single radiator is used. They are 'balanced' in the sense that they now all behave the same...

The boiler in question is a Grant Vortex Eco OIL boiler.

EDIT

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@PhilHornby wrote:
At no point was any measured temperature stable - but the rate of change is now identical when any given single radiator is used.

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Actually, it's just occurred to me that since I didn't measure time at all - I can't talk about 'rate of change'. All I can really say, is that the maximum return temperature of each radiator was the same - given the same maximum flow temperature (i.e. when the flow stat. "clicked off").

[DaveP]

I have been puzzling over this and it seems that none of the options are optimum other than maybe automatic balancing valves.

The whole idea to me of having this system is so that I can have different temperatures in different rooms at different times of day; I only want heat in my bedroom just before I get up and go to bed, the unused back bedroom just needs enough to stop it getting damp, the lounge is the room that requires most heat most of the day, and this is only really relevant when it's cold as they're all off most of the time when it's warm :-).
It may, or may not matter, but I have microbore pipe, so each radiator goes to an upper and lower floor manifold.
I'm enjoying the learning process and I like the system.

[StewartT]

I'm just wondering if we are all overthinking this as an earlier post in this thread seems to support? Unless the lock shield is completely preventing flow, the heat going into a room is proportional to that flow. I am also guessing that the flow balance in the system will be changed (to some extent) by any single valve being between zero and 100% open.  So I personally have done a "first pass" at balancing to ensure after a few minutes no one radiator is wildly different in temperature to its peers. The control system is then left to get on with it to the temperature schedules set and it seems to work "as per schedule". If a particular room over or under-shoots I guess that is a pointer to a further adjustment to the lock shield, or just live with it - law of diminishing returns and all that. BTW I have two valves that go into a "hammering" or pulsing mode on occasion. Both valve bodies are single direction and fitted at the wrong end of the rad (microbore distribution from a non-OpenTherm but variable pump speed WB CDi boiler ). What I have found is that by rotating the TRV coupling a partial turn I can eliminate this effect. 

[DaveP]

Thanks for chipping in, and you are likely right, but it's an interesting conversation. All of my radiators are getting the heat they are set to when I want, so I'm not too bothered, but if I can improve something I'll try :-).
The initial question was about the noise I'm getting and I'm fairly sure it's some form of resonance in the valve or between valve and head, as Phil suggested. Out of interest, I reduced the temperature by 1C yesterday and it's not done it since, but I'm not counting my chickens.

[david101]

One of the causes of resonance in radiator valves is the valve being installed the wrong way round, i.e. against the flow. I think I may have mentioned this previously 😉

[DaveP]

I think you have, and I checked and confirmed that they are, and the main culprit in the dining room is a newish one and is bidirectional anyway

[robertwigley]

I'd try lowering your pump speed. It sounds to me like water pressure through the valve itself and not the iTRV head. If the TRV is not open fully, which the Wiser ones often aren't as they limit the flow in line with demand, then it could be the noise of the water flowing through the valve. Would also explain why when loosening the head, the noise stops, as you're letting the pin in the valve open fully.

[DaveP]

Phil had suggested that, but I have no control over the Baxi combi boiler pump speed, just the temperature, but thanks for you response.

[PhilHornby]

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@robertwigley wrote:

If the TRV is not open fully, which the Wiser ones often aren't as they limit the flow in line with demand, 

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Is there any confirmation from Schneider/Drayton (or anyone else) that they actually do that though❓

I can see how it might be possible, but none of the things I have tried have demonstrated it. I would think they would need intimate knowledge of the valve body to do this properly. 

(It's noticeable that the calibration does not seek the 'fully open' position, only the 'fully closed' position. When you hold the "+" button, it just winds the 'pin' as far into the body as it can.)

[PhilHornby]

I found an interesting post in the 'Home Assistant' forum on this topic...

[DaveP]

It is an interesting read; oddly, without changing anything, it has stopped doing it altogether. Maybe the temperature has affected it; I seem to have everything working well now, with all the TRVs theoretical temperatures tweaked to get the required heat in each room when I want it. Ironically, the room thermostat is superfluous as I don't use it to control the system. BUT it shows me the actual temperature and humidity where I sit.
How's your system doing?

[PhilHornby · Accepted solution]

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@DaveP wrote:

How's your system doing?

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I've been focusing on trying to get my (Oil) boiler to condense more. So messin' with flow-temperatures/balancing/pump speeds etc.

The result is a boiler that now spends more time off than on (i.e. short-cycling) 😒

The temperature readings would suggest that it's all working OK - but I much prefer my radiators HOT, for psychological reasons, if nothing else! 🔥

Going back to these iTRVs 'limited opening' - I'm sure this is a recent battery-saving/noise abatement change. I'm sure they used to open much further originally...

[Lebesgue21]

Hi, I bought wiser TRVs one month ago, and I'm also experiencing noizy valves due to small opening. That's really disappointing, as it wakes me up some mornings (I need to disable confort mode in order to prevent them to open too early 🙁)

They should add an option to control the minimum opening for the TRV to fix this issue!

[DaveP]

It's not happened again; it could be that it hasn't been as cold or that I unscrewed it slightly, or some other reason. I've had another radiator fitted in the lounge and no problem with that one.

As an aside, I am very pleased with the system overall and I used 22% less gas in 2023 than 2022, with similar outdoor temperatures.

The batteries have lasted 10 months minimum and some are still the originals but showing Low, better than expected.

Dave

[Renan_VASSEUR]

Hello all,

Same issue witch Schneider. For some reason the PID love to put the valve at like 5-15% open. So the water force through the valve and made that kind of noise.

the funny thing being that i have an energy meter (flow * Delta T) and the reading is like 80w then the thing is happening. So it’s better to close the valve directlty instead of trying to heat with 80 watts lol

[ericdechelle]

Got a similar noise on some of my TRVs (I've 8 of them) , finally exchanged some between rooms : noise didn't come again
As well, it was not handling correctly the temperature set on Wiser App on 2 systems,  leaving the valve fully opened so the radiator was really hot (it went away as well after exchanging TRVs)