Discuss Faulty actuators or valves? in the Water Underfloor Heating Advice area at Plumbers Forums

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8
Hi

I have a 4 zone / 7 loop UFH system.

2 zones (4 loops) always get hot when the system is on when the zone thermostats and actuators are off.

The video posted shows when I turn on another zones the flow meters drop. (Kitchen prep and kitchen TV are the issue, two at either end of the manifold).

The actuators light up and seem to be receiving signal from the controller.

A plumbing engineer inspected yesterday and because he could manually push down the valve pin on one of the faulty loops determined that all 4 actuators must be faulty and should be replaced.

The actuator is a Watts 26L230NC2 normally closed model.

Today I tried switching one of the actuators from a zone that is working correctly (front lounge label) to one of the faulty loops (kitchen prep) there was no difference to what is seen in the video when turning on one of the correctly functioning zones - implying the actuator functions correctly.

From a manual press of the valve pins I could not discern any notable level of greater force required between the working and faulty loops.

I don’t think this is an issue with the actuators. Is there a way to confirm the valves work as intended? How much force should be needed to close the valve? Is it possible the actuators are incorrect and not strong enough to keep the valves closed and failed over time?

Any advice appreciated.
 
actuators can take time to open . in your vid you can hear the relay but it can take 2/3 mins for the actuator to start to open
 
actuators can take time to open . in your vid you can hear the relay but it can take 2/3 mins for the actuator to start to open
These actuators are normally closed so I thought should be closing the valve (pushing down the pin) when off. My vid shows when turning on another zone the flow meters drop straightaway on these zones indicating the actuator was not closing the valve as it should

Actuator off

IMG_1386.jpeg


Actuator on - calling for heat


IMG_1385.jpeg
 
Just a bump on this older question as the gas bills go up again…..

I don’t think this is an issue with the actuators. Is there a way to confirm the valves work as intended? How much force should be needed to close the valve? Is it possible the actuators are incorrect and not strong enough to keep the valves closed and failed over time?
 
Those Watts actuators are thermally actuated. I have a similar type, but not Watts brand, on my manifold, and they take maybe a minute to open, and they open fairly slowly, rather different behaviour to the video (if that is in real time).

Is a pump coming on only when you turn on the other zone at the start of the video?

I'm wondering if the pump is forcing water through the theoretically closed valves, but why just those and not all of them?
 
Those Watts actuators are thermally actuated. I have a similar type, but not Watts brand, on my manifold, and they take maybe a minute to open, and they open fairly slowly, rather different behaviour to the video (if that is in real time).

Is a pump coming on only when you turn on the other zone at the start of the video?

I'm wondering if the pump is forcing water through the theoretically closed valves, but why just those and not all of them?

Yes the actuators take a minute or two to open after the controller turns them on. I tested one whilst off the manifold and you can see the element in the middle move upwards into the case of the actuator as it warms up.

Whilst the pump is running you can also manually close the pin valve on the problematic zones using the handle of a screwdriver etc to push on it, the corresponding flow meter then goes up as you would expect if the zone were off.

So for me got to be an issue with the pin valves. Maybe wrong spec or seated incorrectly, so just too stiff for the actuator to close it? I am tempted to change one valve myself but not sure how to identify the correct replacement part before removing. Maybe I could also buy a cap to screw down onto the pin valve and force it closed? Then at least I can run and control the other zones.

The x4 faulty valves cover 2 very large zones in a well insulated extension so hardly need any heat anyway!
 
Yes the actuators take a minute or two to open after the controller turns them on. I tested one whilst off the manifold and you can see the element in the middle move upwards into the case of the actuator as it warms up.

Whilst the pump is running you can also manually close the pin valve on the problematic zones using the handle of a screwdriver etc to push on it, the corresponding flow meter then goes up as you would expect if the zone were off.

So for me got to be an issue with the pin valves. Maybe wrong spec or seated incorrectly, so just too stiff for the actuator to close it? I am tempted to change one valve myself but not sure how to identify the correct replacement part before removing. Maybe I could also buy a cap to screw down onto the pin valve and force it closed? Then at least I can run and control the other zones.

The x4 faulty valves cover 2 very large zones in a well insulated extension so hardly need any heat anyway!
Sorry I don't think my brain is awake!
Your video seems to show switching on heat for the kitchen. What did you turn on, and why does the flow start so quickly when the valves take a while to open? Is it that they were already hot, or is it that the pump came on, or both.
 
So for me got to be an issue with the pin valves. Maybe wrong spec or seated incorrectly, so just too stiff for the actuator to close it? I am tempted to change one valve myself but not sure how to identify the correct replacement part before removing. Maybe I could also buy a cap to screw down onto the pin valve and force it closed? Then at least I can run and control the other zones.
if you know the brand of the manifold it should be possible to track down spare valve assemblies.
The screw cap idea seems the way to go as a temporary fix.
What was in my mind, as it featured as I was getting my system going, was that the pump is on too high a setting and forcing water through what should be closed valves. But then why just the two long loops affected? I wondered, as an experiment, if you had tried turning down the pump to see if that made any difference. 🤔
 
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if you know the brand of the manifold it should be possible to track down spare valve assemblies.
The screw cap idea seems the way to go as a temporary fix.
What was in my mind, as it featured as I was getting my system going, was that the pump is on too high a setting and forcing water through what should be closed valves. But then why just the two long loops affected? I wondered, as an experiment, if you had tried turning down the pump to see if that made any difference. 🤔
I just tried lowering the speed but no difference. In the original video I was turning on the front lounge only but as you can see flow meters drop straight away to x4 loops in the kitchen as if the actuator was doing nothing. The new video shows me manually pushing the pin valve down on one of the kitchen loops whilst only the front lounge (3rd and 4th from the right) are actually on. When the whole system is turned off and the motorised valve shuts, all flow meters return to the top.

I can’t work out the brand of the manifold, it has Reliance ball valves at either end but no Reliance branding on the actual manifold.

Much appreciate your ideas!

 

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The quality label top right of your manifold suggests a date of Oct 2016, and after a quick look, found the UK website below showing an installation in 2014, which looks similar!' Would that tie up with the date of yours?

Henco don't seem to be making it any more, though their brass version looks similar.
Polypipe spares seem to claim some of their spares are compatible with Henco, and I think the Polypipe blue caps might fit:


Polypipe also seem to do a valve claimed to be suitable for Henco. The valve has a rubber? washer - I don't know if that is replacable?

IMG_0397.jpeg
 
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The quality label top right of your manifold suggests a date of Oct 2016, and after a quick look, found the UK website below showing an installation in 2014, which looks similar!' Would that tie up with the date of yours?

Henco don't seem to be making it any more, though their brass version looks similar.
Polypipe spares seem to claim some of their spares are compatible with Henco, and I think the Polypipe blue caps might fit:
Thank you that is brilliant! I have not been able to identify the manifold brand but yes it looks similar.

I am guessing mine was installed between 2016 and 2018 before I owned the property. The BC certificate for the extension is 2018.

The blue caps look just like the one on the spare return port so I have purchased a set and will give the quick fix a go.

One day I will have a got a removing a valve and then compare to parts available. Maybe summer time!
 
I don't see there is anything different in the way it's plumbed from the Henco example setup (admittedly incomplete!) I posted.
The mixing valve is set at about 47 which seems a tad high to me, but otherwise I don't see anything wrong.
 
Fitted the blue cap and keeps the valve closed. Was not in anyway difficult to tighten. Maybe there is an issue with the actuator maybe not compatible with the pin valve but doesn’t explain why the others work! 🤦‍♂️
 
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