Hi,
My central heating system is working OK but I have an annoying problem with the above valve.
Sometimes when the central heating / hot water has turned off the valve will buzz. If I switch the electrical power off then on from it for a few seconds it stops!

Is there a fault with it and if so could I just change the actuator or do I need to change the entire valve?

Thanks

In message , waltfen
writes

Hi,
My central heating system is working OK but I have an annoying problem
with the above valve.
Sometimes when the central heating / hot water has turned off the
valve will buzz. If I switch the electrical power off then on from it
for a few seconds it stops!

Is there a fault with it and if so could I just change the actuator or
do I need to change the entire valve?

Is it hovering around the mid position ?

That would be one of the microswitches in the actuator head gone

--
geoff

My central heating system is working OK but I have an annoying problem
with the above valve.
Sometimes when the central heating / hot water has turned off the
valve will buzz. If I switch the electrical power off then on from it
for a few seconds it stops!

Could be low voltage. When you switch off and on again you could
produce a small surge that shocks it into position.

In message .com,
Merryterry writes
My central heating system is working OK but I have an annoying problem
with the above valve.
Sometimes when the central heating / hot water has turned off the
valve will buzz. If I switch the electrical power off then on from it
for a few seconds it stops!

Could be low voltage. When you switch off and on again you could
produce a small surge that shocks it into position.

Really ?

where do you think the volts are disappearing to then ?

--
geoff

In message .com,
w_tom writes
Some solenoid valves have a detachable coil. This so that same valve
body can be used with coils for different voltages. These coils were
held in place by a strong spring, but some would still buzz. I then
removed the coil, applied some transistor heat sink compound or a high
temperature (wheel bearing) lubricant on what that coil would slide
down on, and reassembled the valve. That high temperature cream would
dampen vibrations - no more noise.

There is no coil - there's a synchron motor

--
geoff

Thanks for everyone's help.
I've changed the actuator and so far so good - no buzzing. Let's hope it lasts!