Noisy motorised value

lcoachman

I have just had a New boiler fitted, I have changed to a Combi boiler. When my boiler fires up my motorised valve often makes a loud burrrring noise. Ive had a new valve fitted and the new one is still doing it. The plumber says I’ve just got to live with it. It sounds like there is too must pressure coming from the boiler for the value, the level of noise changes, it’s sometimes soft and other times it’s very loud.. can anyone help please. 

Jeepers_Creepers

You say motorised valve - singular? On a combi? So you have more than one heating zone, then? This a diverter valve - one inlet and two outlets - and these go off to two separate radiator zones? And what make is this valve?

In general, tho', these valves should whirrrr when they operate, and then remain quiet in whichever position they are placed. A 3-porter has one 'end' set under spring pressure only (so zero sound) and the other end is held under motor pressure (so a whirr while it gets there, but this should be followed by silence too). The centre position - both ports open - is similarly held by the motor on what is effectively 'trickle' power - just enough to keep it there. 

The valve should stop making a noise once it's reached any of these 3 positions. I suspect it hasn't been wired correctly and the motor is possibly receiving full power even when at mid or end positions - that would certainly explain the continued buzzing. 

WHOOPS! It doesn't make this noise ALL the time, just when the boiler fires up and it operates the valve for a few seconds? Still seems strange, and I don't see how water flow would cause this.

Can you post a photo of the valve in relation to the boiler? Can both be seen together? The valve hasn't been fitted to the 'return', has it?! 

A better setup in general is to have two separate 2-port valves instead of a single 3-porter. More decisive control, much better flow, just better. Easy to change to this too. ('S'-plan instead of 'Y'-plan). 

fenwick458

make sure theres no air in the system. I can't say it'll get rid of the noise completely but it'll help.
when my boiler knocks off as it's pumping against 2 closed zone valves for 2 mins or so it used to make a wooshing noise, well bleeding it thoroughly has made that noise a bit less.
I used to bleed at my mag filter right below the boiler (on the first floor), it took a couple of weeks to get all of the air out

lcoachman

Jeepers_Creepers said:

You say motorised valve - singular? On a combi? So you have more than one heating zone, then? This a diverter valve - one inlet and two outlets - and these go off to two separate radiator zones? And what make is this valve?

In general, tho', these valves should whirrrr when they operate, and then remain quiet in whichever position they are placed. A 3-porter has one 'end' set under spring pressure only (so zero sound) and the other end is held under motor pressure (so a whirr while it gets there, but this should be followed by silence too). The centre position - both ports open - is similarly held by the motor on what is effectively 'trickle' power - just enough to keep it there. 

The valve should stop making a noise once it's reached any of these 3 positions. I suspect it hasn't been wired correctly and the motor is possibly receiving full power even when at mid or end positions - that would certainly explain the continued buzzing. 

WHOOPS! It doesn't make this noise ALL the time, just when the boiler fires up and it operates the valve for a few seconds? Still seems strange, and I don't see how water flow would cause this.

Can you post a photo of the valve in relation to the boiler? Can both be seen together? The valve hasn't been fitted to the 'return', has it?! 

A better setup in general is to have two separate 2-port valves instead of a single 3-porter. More decisive control, much better flow, just better. Easy to change to this too. ('S'-plan instead of 'Y'-plan). 

Thank you for replying, I have 2 motorised valve, yes 2 zones. The valves are next to each other. They are hollewell valves. They do make a  slight noise when they turn on but this is a grrrrring noise when the boiler turns on. There are many elbow joints around the area of the valves and I wonder if its a pressure problem, but weirdly sometimes it doesn’t make any noise when the boiler turns on And other times it really grrrrrres. 

vacheron

fenwick458 said:

make sure theres no air in the system. I can't say it'll get rid of the noise completely but it'll help.
when my boiler knocks off as it's pumping against 2 closed zone valves for 2 mins or so it used to make a wooshing noise, well bleeding it thoroughly has made that noise a bit less.
I used to bleed at my mag filter right below the boiler (on the first floor), it took a couple of weeks to get all of the air out

If your system pumping against static pressure for 2 minutes after switching off it sounds like it has trying to use an auto run-on feature to stop heat accumulating in the boiler. It could be worth having an auto bypass valve fitted which may extend the life of the boiler (they only cost about a tenner).

I did this when I moved from a mid position "Y" layout to a 2 Zone + HW layout when I had underfloor heating fitted in our extension so that the boiler could use a loop of copper piping as a radiator when all the other valves were closed.

Apodemus

Yes, I was wondering, too, if it was the increased noise of the pump remaining in over-run until the motorised valves open up? 

vacheron

lcoachman said:

Jeepers_Creepers said:

You say motorised valve - singular? On a combi? So you have more than one heating zone, then? This a diverter valve - one inlet and two outlets - and these go off to two separate radiator zones? And what make is this valve?

In general, tho', these valves should whirrrr when they operate, and then remain quiet in whichever position they are placed. A 3-porter has one 'end' set under spring pressure only (so zero sound) and the other end is held under motor pressure (so a whirr while it gets there, but this should be followed by silence too). The centre position - both ports open - is similarly held by the motor on what is effectively 'trickle' power - just enough to keep it there. 

The valve should stop making a noise once it's reached any of these 3 positions. I suspect it hasn't been wired correctly and the motor is possibly receiving full power even when at mid or end positions - that would certainly explain the continued buzzing. 

WHOOPS! It doesn't make this noise ALL the time, just when the boiler fires up and it operates the valve for a few seconds? Still seems strange, and I don't see how water flow would cause this.

Can you post a photo of the valve in relation to the boiler? Can both be seen together? The valve hasn't been fitted to the 'return', has it?! 

A better setup in general is to have two separate 2-port valves instead of a single 3-porter. More decisive control, much better flow, just better. Easy to change to this too. ('S'-plan instead of 'Y'-plan). 

Thank you for replying, I have 2 motorised valve, yes 2 zones. The valves are next to each other. They are hollewell valves. They do make a  slight noise when they turn on but this is a grrrrring noise when the boiler turns on. There are many elbow joints around the area of the valves and I wonder if its a pressure problem, but weirdly sometimes it doesn’t make any noise when the boiler turns on And other times it really grrrrrres. 

The motoised valves and synchronous motors have gearboxes inside. If the teeth have worn they may be slipping causing the noise and that would persist until the valve finally reached its final position. Have you taken the motor unit of the valve itself (this is quite easy to do) to see if the valve turns easily and isn't stiff?  

lcoachman

Ive tried to send a photo of the valves in relation of the boiler but it tell me I’m 3 characters too short, I don’t know what the means 

Jeepers_Creepers

lcoachman said:

Thank you for replying, I have 2 motorised valve, yes 2 zones. The valves are next to each other. They are hollewell valves. They do make a  slight noise when they turn on but this is a grrrrring noise when the boiler turns on. There are many elbow joints around the area of the valves and I wonder if its a pressure problem, but weirdly sometimes it doesn’t make any noise when the boiler turns on And other times it really grrrrrres. 

Ah, so I completely misinterpreted the situation then :-(

Cool, you have two zone valves - that's good. Ok, if wired correctly, the sequence of events in firing up your boiler is - timer turns on and sends signal to room thermostat (quite likely a combined Prog-Stat?). Thermostat calls for heat and sends signal to appropriate motorised valve(s). Motorised valve opens and THEN sends the signal to the boiler to fire up. 

Ie, the boiler should not come on until the valve has opened. 

This is easy to check if the valve and boiler are close. Turn up room stat and run to the valve. You should hear a whirr for 2-3 seconds and then a 'click'. The boiler should come to life only then.

If the boiler is pumping against a closed valve, then the internal by-pass will be triggered. I wonder if that's what the sound is? As far as I know, all modern boilers have built-in by-pass valves. 

Lcoachman, can you check if the sequence is as I outlined above? Ie the valve whirrs, clicks, and then the boiler fires? 

And silly question, are the valves fitted the correct way around?! 

lcoachman

The piping length from the boiler to the valves is about 20 ft. 

Jeepers_Creepers

Lcoachman, can you check if the sequence is as I outlined above? Ie the valve whirrs, clicks, and then the boiler fires?