Steve wrote:
Christian McArdle wrote:
When I had the casing off of the actuator, the heat was coming
from the silver coloured drum shaped object - presumably the motor.


I have since left the lever in the central position and the motor has
cooled down.

It sounds like the head is totally knackered. Persist with removing the
thing. Any springs are part of the head and it is of no relevence if they
are damaged or lost.
If I do this, can I safely continue to use the system for water heating
until I can find a replacement?


Once the head is off, make sure the spindle turns relatively easily.
If so,
you can probably just put a new head on it. You might even get away with
replacing just the motor bit. It is called a "synchron motor" and is
easy to
source if you don't mind a little soldering.
It's 15 years old, so I think I'd probably be happier renewing the whole
actuator.

However that means draining down the pipework.

What happened to one of my 20ways was that the motor got tired somehow,
and the valve got stiff.

Removing the head allowed me to wiggle the valve, and a new head cured
all other problems.


Am I right in thinking that a plumbers merchant is the place to go for
this sort of thing?


Yes. Take copious photos, try and get the head off and work teh valve
manually. It its reasonably free, disconnect electrics and take head in.

ISTR I got a new head online somewhere tho.


Christian.