Buzzing Honeywell Motorised Valve - How easy to fix?

luckwudaveit

Since having our bathroom renovated, which included replacing a single radiator with a double, there has been a buzzing / humming noise coming from the boiler. Tonight, I think I have narrowed it down to the Honeywell V4043H motorised valve.

The hot water and heating are 2 separate systems, each with their own motorised valves, located under the boiler in a cramped cupboard under the stairs, with the valves about 200mm off the floor. When the call is received for the heating, the buzzing starts in a rythmic fashion, lasting longer when the system is cold (ie mornings) but not as long in the evening if the system hasn't fully cooled down from a previous call.

So far, the heating has always come on, but I fear the worst if I don't do anything. I have done some background reading and it seems like the motor is simple to replace. I would quite like to give it a go myself, but the access (mentioned above) is made worse as the valve has been fitted upside down, so the lid is underneath.

This valve failed completely, without warning, about 3 years ago and a whole new valve was fitted.

Would I be best just getting a plumber out?

david29dpo

Is it the type that you can unclip the valve head?

Biggles

There is a faint buzzing coming from mine, all the time. My heating engineeer says there is always power to them, even when the heating isn't running, and this is normal.

keystone

The rhythmic nature suggests that the head is trying to drive the valve into the open position but is failing to quite get it to the point where the microswitch operates. That could be because the work you have had done recently has stirred up some carp in the system which has lodged in the valve body. Remove the head (no sorry it isn't the quick release type) and operate the valve manually. Whilst you have the head off get someone to operate the roomstat so that the system calls for heat. See what the head actually trys to do and what noises it makes when its off the valve body. This needs someone else to operate the stat while you hold the head and monitor what it does.

BTW the guy who fitted it three years ago did fit it the right way round did he? There's an arrow on the body and if its trying to open against the flow as opposed to with the flow then it will puff a bit.

Cheers

luckwudaveit

keystone wrote: »

The rhythmic nature suggests that the head is trying to drive the valve into the open position but is failing to quite get it to the point where the microswitch operates. That could be because the work you have had done recently has stirred up some carp in the system which has lodged in the valve body. Remove the head (no sorry it isn't the quick release type) and operate the valve manually. Whilst you have the head off get someone to operate the roomstat so that the system calls for heat. See what the head actually trys to do and what noises it makes when its off the valve body. This needs someone else to operate the stat while you hold the head and monitor what it does.

BTW the guy who fitted it three years ago did fit it the right way round did he? There's an arrow on the body and if its trying to open against the flow as opposed to with the flow then it will puff a bit.

Cheers

Thanks for your reply. I don't know much about heating / plumbing so I'm a bti concerned about taking the cover off the unit and messing around with it whilst power is live to it.

What you say about the recent work stirring up the system and causing something to lodge in the valve makes sense. I have bled all the radiators and the first 2 times a lot of air came out, as well as a lot of black gunk. A further couple of bleeds and there is no more air or black stuff coming out, just clear (ish) water.

The valve is fitted in the same way as the one adjacent to it for the hot water and he hasn't touched this at all.

This is sounding more and more like I should just get the plumber back out. I fear I will spend money and a lot of time changing the motor and it won't be that.

keystone

luckwudaveit wrote: »

Thanks for your reply. I don't know much about heating / plumbing so I'm a bti concerned about taking the cover off the unit and messing around with it whilst power is live to it.

Sorry you have misunderstood or I haven't explained myself properly. The whole of the silver box comes off the valve body without compromising electrical safety. Then you can operate the valve itself manually and also check the operation of the actuator (the silver box). I am certainly not advocating removing the cover of the silver box to expose the innards whilst it is connected to the electricity supply.

Cheers

luckwudaveit

keystone wrote: »

Sorry you have misunderstood or I haven't explained myself properly. The whole of the silver box comes off the valve body without compromising electrical safety. Then you can operate the valve itself manually and also check the operation of the actuator (the silver box). I am certainly not advocating removing the cover of the silver box to expose the innards whilst it is connected to the electricity supply.

Cheers

OK, thanks!

gas4you

keystone wrote: »

Sorry you have misunderstood or I haven't explained myself properly. The whole of the silver box comes off the valve body without compromising electrical safety. Then you can operate the valve itself manually and also check the operation of the actuator (the silver box). I am certainly not advocating removing the cover of the silver box to expose the innards whilst it is connected to the electricity supply.

Cheers

Only if it is a 'modern' Honeywell valve with a raised 'dimple' on the silver metal head.

keystone

gas4you wrote: »

Only if it is a 'modern' Honeywell valve with a raised 'dimple' on the silver metal head.

OP says only 3 years old so assumed - perhaps rashly.

Cheers

gas4you

oops, sorry, didn't read that bit. Just went into auto mode.

luckwudaveit

I buckled and got a plumber out in the end. Turns out it was just the synch motor and I'm £54 lighter for it. Kind of wish I'd tried to change it myself; still its done with little effort from me.

Thanks everyone for your help.