Clicking noise from UFH manifold when it fires up

[thefoxesmaltings]

Got this clicking sound from one of the underfloor heating manifolds. It doesn't sound like it's coming from the pump, but the manifold itself. To be honest it's quite hard to pinpoint where it's coming from exactly.

It starts when the manifold first fires up each time, with the clicking happening very frequently, but over the course of a couple of minutes gradually slows down, and finally stops.

Any ideas?

 

 

 

[Alan Ambrose]

Sounds like expansion noises due to ... heating. Is it bothersome? Radiators sometimes make this noise - probably from the manifold fixings?

[thefoxesmaltings]

37 minutes ago, Alan Ambrose said:

Sounds like expansion noises due to ... heating. Is it bothersome? Radiators sometimes make this noise - probably from the manifold fixings?

So I've narrowed the noise coming specifically from one of the actuators. But the actuator seems to still be opening and closing correctly, so doesn't suggest a stuck pin?
It's a bit bothersome to be honest - quite loud!

[Super_Paulie]

could unscrew the actuator and see if it makes the noise when its not attached to the manifold? would at least tell you if its the actuator or the valve pin movement.

[zzPaulzz]

Thought I'd ask ChatPGT

A clicking noise coming from your Underfloor Heating (UFH) actuator can be concerning and may indicate an issue that needs attention. The actuator is a critical component in a UFH system, controlling the flow of hot water by opening and closing valves based on signals from the thermostat. Here are some reasons why your UFH actuator might be clicking and what you can do about it.

 

Possible Reasons for the Clicking Noise

 

1. Normal Operation Sounds:

• Valve Movement: Some clicking is normal as the actuator opens or closes the valve. This sound is usually soft and infrequent.

• Design Characteristics: Certain actuator models are inherently noisier due to their mechanical design.

2. Frequent Opening and Closing (Short Cycling):

• Thermostat Settings: If the thermostat is set with a narrow temperature differential, the system may turn on and off rapidly.

• Room Temperature Fluctuations: Drafts or external heat sources can cause the thermostat to activate the actuator frequently.

3. Faulty Actuator:

• Mechanical Failure: Worn-out gears or components inside the actuator can produce a clicking sound.

• Stuck Valve: If the valve is sticking, the actuator might struggle to move it, resulting in repeated clicking.

4. Electrical Issues:

• Power Supply Fluctuations: Inconsistent voltage can cause the actuator to malfunction.

• Wiring Problems: Loose or damaged wires might lead to intermittent signals, causing the actuator to click.

5. Loose Mounting or Components:

• Vibration: An improperly secured actuator can vibrate or move, amplifying operational noises.

• Loose Valve Linkage: The connection between the actuator and the valve might be loose.

6. Air in the System:

• Air Locks: Trapped air can cause uneven water flow and noises resembling clicking.

• System Bleeding Needed: Releasing the air can resolve the issue.

7. Thermostat Issues:

• Faulty Thermostat: Sending incorrect signals to the actuator.

• Battery Low: In wireless thermostats, low batteries can cause erratic behavior.

 

Troubleshooting Steps

 

1. Observe the Pattern:

• Timing: Note when the clicking occurs—constantly, intermittently, or only when the system starts or stops.

• Correlation: See if the noise coincides with temperature changes or thermostat adjustments.

2. Check the Thermostat Settings:

• Temperature Differential: Adjust the settings to prevent rapid cycling.

• Location: Ensure the thermostat is not exposed to drafts or direct sunlight.

3. Inspect the Actuator:

• Visual Inspection: Look for any visible damage or loose parts.

• Mounting: Ensure the actuator is securely attached to the manifold and valve.

4. Examine Electrical Connections:

• Wiring: Check for loose or frayed wires connecting the actuator to the control system.

• Power Supply: Verify that the voltage is stable and within the actuator’s specifications.

5. Bleed the System:

• Release Trapped Air: Use the bleed valves on the manifold to remove any air pockets.

• Professional Help: If unsure, have a technician perform the bleeding.

6. Test the Actuator:

• Manual Operation: Some actuators allow for manual opening and closing to test functionality.

• Replace if Necessary: If the actuator is faulty, replacing it may resolve the clicking.

 

When to Consult a Professional

 

If the clicking persists after basic troubleshooting, it’s advisable to contact a qualified heating engineer or technician. Professional assistance is recommended when:

 

• Persistent Noise: The clicking continues despite checking common issues.

• Uncertainty: You’re unsure about performing electrical checks or system bleeding.

• System Performance Issues: Reduced heating efficiency or uneven floor temperatures.

• Safety Concerns: Suspected electrical faults or potential damage to the system.

 

Preventive Measures

 

• Regular Maintenance: Schedule periodic inspections of your UFH system to catch issues early.

• Quality Components: Use reliable actuators and thermostats from reputable manufacturers.

• Proper Installation: Ensure that all components are installed correctly by professionals.

 

Conclusion

 

A clicking UFH actuator can result from various factors ranging from normal operational sounds to mechanical or electrical issues. By systematically troubleshooting the possible causes, you can identify and often resolve the problem. If in doubt, seeking professional help will ensure your underfloor heating system operates efficiently and safely.

[Alan Ambrose]

>>> So I've narrowed the noise coming specifically from one of the actuators.

 

Neat, well done. Try and reseat the actuator (pull it off and put it on again) to see if that helps.

 

If not, just replace it - they're about 20 quid each. They can be 24V or 240V - in any case power off the controller when you're changing it. To make life simple, just buy the exact same actuator model you have now.

Edited October 22 by Alan Ambrose

[JohnMo]

6 minutes ago, Alan Ambrose said:

just replace it - they're about 20 quid each.

Or ask yourself do you need the actuators? You could just run open loop and weather comp. Set your thermostat(s) to about 24 so the actuators stay open all the time, noise will never come back. 

[thefoxesmaltings]

50 minutes ago, Alan Ambrose said:

>>> So I've narrowed the noise coming specifically from one of the actuators.

 

Neat, well done. Try and reseat the actuator (pull it off and put it on again) to see if that helps.

 

If not, just replace it - they're about 20 quid each. They can be 24V or 240V - in any case power off the controller when you're changing it. To make life simple, just buy the exact same actuator model you have now.

Done that. Should the actuator pin move loosely and freely if there is no heating demand at the moment?

It does move, up and down if I press it, but takes a fair bit of pressing, and almost if like there is pressure behind it.

 

Edited October 22 by thefoxesmaltings
Correction

[Alan Ambrose]

From memory there's a fair bit of pressure required. I think there's a strong-ish spring under the plunger and, of course, a valve. The actuators are quite interesting in that they work by heating up wax which expands and then forces the pin down. When the heat is removed, the wax cools and shrinks and the spring helps push the pin/plunger up again. That's why they work quite slowly. You could try pushing the pin up and down a bit - that will require quite a bit of force - to see whether that's the part that's causing the noise.

 

You could compare with its actuator neighbour.

 

If you're being clever (mark the actuators in advance) you can swap over actuators between valves/circuits and see whether the noise is connected to the valve or the actuator. You'll need to be careful to figure out which stat is controlling which actuator / valve combination. Read off the actuator model code while it's easy, so you can source a new actuator if you need it.

 

I've just twigged that this is a newish installation, so you might just have a dodgy actuator or valve installed. It's possible that there was something wrong with the valve install, although that's fairly unlikely. Can you not just get the original plumber back in?

Edited October 22 by Alan Ambrose

[Alan Ambrose]

It occured to me that another simple option to figure whether it is actuator or valve is simply to take the actuator off as you have done, operate it via the controller, and see if it clicks. If not, it's the valve.

[John Carroll]

Do these actuators act like a TRV with a wax/liquid filled capsule?, I thought the might just position the valve based on the signals from from the controller which then drives the motorized actuator.

Edited October 23 by John Carroll

[Alan Ambrose]

I'm pretty sure they're just on/off style (and it takes a minute say to switch from one state to the other). That is, heat the wax, or don't heat the wax.

 

https://en.wikipedia.org/wiki/Wax_motor

 

https://waxmotor.com/blogs/introduction-to-thermal-actuator