Siemens CMV 322 Motorised Valve - Problem

[willingz]

Seems to be stuck in a mid-position because when CH on (and programmer at CH only) a lot of heat gets to HW , the temperature of which rises way above cylinder thermostat setting.

Valve is 7 years old and from what I've recently read it seems Siemens valves are not noted for their long lives.
Is there an easy fix pending replacement ( hopefully when winter is over) with a Honeywell ?

All views appreciated.

 

[oldbuffer]

1. System off. Take the actuator head off the valve. They just pull off.
2. Try turning the spindle of the bit left attached to the pipes. It probably doesn't turn more than about 20 degrees, but should rotate freely with the fingers, or without force with a pair of pliers.
3. If the spindle is stiff, try turning it backwards and forwards to try and free it up. Don't oil it or use WD40, it could damage the seals inside.
4. If the spindle turns freely, then there is likely to be a fault with the actuator mechanism. You could get a new valve (Siemens again) and use the actuator. Not sure if you can get the actuators separately, but they are usually nearly expensive as the whole valves.
5. None of the above involves getting wet, but does require caution with the mains voltage electricity involved. Make sure the system is off, and check all wires for voltage(s) to earth (green / yellow) and neutral (blue).

 

[willingz]

Many thanks. Will try this.

 

[dilalio]

7 years for a £70 device that is used constantly! Not bad really eh?

 

[willingz]

As I was not making progress to cure fault , plus pressure from daughter to get something done, I've today had an engineer fit a new Honeywell. All now OK.
Re dilalio's comment: I can only say that original Landis & Gyr valve lasted 18 years until I shorted the circuit board whilst carelessly fitting a new motor after Xmas dinner- perhaps there was too much brandy in the pudding.

 

[dilalio]

Re dilalio's comment: I can only say that original Landis & Gyr valve lasted 18 years

Get another one of those then!

 

[ianmcd]

Get another one of those then!

 

[willingz]

Sadly by the time I killed their valve L&G had long been taken over by Siemens, whose CMC322 was the direct replacement.

 

[dilalio]