Faulty motorised valve?

Hello all. I've had some great help in the past from this wonderful forum so hopefully you can help me again!

I know nothing about plumbing but like to get some background information to see if I need to get some proffessional help in.

The problem I have is a rythmic buzzing sound coming from an area near my boiler. On closer inspection the sound is coming from a metal box which on one side says (along with a lot of other stuff) 'Honeywell' and 'motorized valve'. So using my special powers of observation I presume that this unit is a Honeywell motorized valve??!!

So, have any of you experts come across this phenomenom before? The buzz is quite loud (loud enough to keep waking my 1 year old son whose room backs onto the boiler cupboard). Like I stated previously, it's rythmic in nature and only seems to happen every time the heating kicks in and then stops after about a couple of minutes or so. Does it sound like it's on it's way out? The house is 5 years old and we've already had to have the Grundfos pump replaced too.

Any help greatly appreciated!

BOILER MAKE AND MODEL??

Just replace the head on the valve,if you feel confident with some diy electrical work,if not its an easy fix for a boiler engineer.

HARALIAN said:

BOILER MAKE AND MODEL??

Click to expand...

it's an Ideal Classic FF350

You'll have to learn more on how this valve works to understand what is going on.
briefly, it operates over two sections. power from one wire (white) drives motor to turn valve to mid point, where another source of power takes over (grey wire) to take the valve across the second section to CH only.
So in this position the 'grey' keeps the motor energised and keeps the valve against its stop. At the same time, power is allowed out of the actuator head via the orange wire to light and keep the boiler/pump going.
When heating is satisfied or turned off at programmer, power out of the orange is cut, so boiler stops, But the motor stays energised and that is the noise you can hear.
If you turn CH off and put HW on, both grey and white become dead.
Spring will return valve To HW position and motor no longer energised.
You could replace the motor for about £15 and the buzzing may be reduced.
If you have selected both HW and CH, the story is slightly different.
The valve can be in any of the three positions and will change to any other position according to the 'demand'. HW is not in demand to the same degree as CH, but if hw is used valve will drop back to either mid position or HW position.
So in HW position motor not energised.
In CH position motor enrgised 230 volts.
In mid positon motor energised with modified voltage to hold valve against the return spring.

Had exactly the same problem after my plumber replaced a very old Honeywell valve. The new one hums after heating on and only stops when either hot water only comes on or the power is turned off. My plumber fitted a new unit but still the same problem. The weird thing is, if you remove the honeywell cover the noise seems to stop. The motor is still humming but you can only hear it by putting a screwdriver t your ear and to the motor. I guess the cover acts as an amplifier. I obviously don't like to leave the cover off or even loose. Any further help appreciated.