3 Port valve

[Mahadev]

I have a Landis & Staefa MAV322 3 port valve bought from Wickes fitted to the CH system. Currently it only fires up the boiler when the HW thermostat demands 'heat'. Although the room thermostat appears to work when checking the voltages, the boiler does not fire up independently when CH 'heat' is demanded.
Is this model the same as Seimens CAV322 which I can get for £20 less than the Wickes model.
I recall on the instructions it stated do not remove the head from the valve body.
As virtually all other models including the look alike Seimens state you can separate the 2, I am puzzled to why the Landis & Staefa state otherwise?
Is this just a con to encourage people to buy the whole thing again or am I just looking for an easy answer?
Does anyone know if repair kits are available (Motor, micro switches etc. for these type of valves?
Thanks for your interest
MahadevDave

 

[seco services]

I have a Landis & Staefa MAV322 3 port valve bought from Wickes fitted to the CH system.

is this a new install ?

if your Landis & Staefa does not have a c on the end of the model number it has a fixed head.

 

[Mahadev]

Hi
Thanks for your speedy reply.
Answers:-
No, installed 9 years ago.

Manufacturers label states,
Part nos. MAV322
BGC nos 397892
No sign of a 'C'

Thoughts?
There is just one screw holding the cover on, any tell tale signs if I remove this?
Why do some have removable heads and others not?

 

[seco services]

not being a fan of Landis & Staefa.
you can take the cover off but the actuator won't sepate from the valve
only the ones with C on the end of the model n0 seperate.

remove the lid sounds like the motors gone.