SUNVIC SD2701ACTUATOR & XL207 PROGRAMMER

[gas4you]

Depends what isolating valves are near it. You may get away with a partial drain down assuming it is in an upstairs airing cupboard, but this may cause air lock probs afterwards.

A freezing kit could be another option.

 

[Gasguru]

Don't want to speak too soon but looks like you guys know your stuff!!!

Turned the spindle with my pliers and then put the actuator back on and it now seems to be ok .

I said with your fingers

If you needed pliers the valve spindle is siezed. It will appear to work but once the clock/room stat turns off the heating and there is a hot water demand the spring within the valve actuator may not not have enough oomph to turn the spindle back to the hot water position - then your rads will get hot with thjust the water on. (I'm assuming this is a 3 port mid position valve setup).

I would drain the whole system and replace with a Honeywell. Alternatively you could buy another valve body and just swap the inards if the brass is not too worn inside (where the shoes contact).





gas4you your thinking of the MoMO (motor on/motor off) valves. There have been various incarnations of this actuator over the years. As you remember its runs the spindle through a full 180 each time. They sell them on their energy savings (the motor is not powered continously with a demand). I calculated less than a pound a year saving for a typical setup!

Interestingly the latest MoMo valves are shipped with Range unvented cylinders. The regs call for spring return so there appears to be another anomoly in the CE and type approval.

 

[gas4you]

Thanks GG. Nice to know I am still partly sane

 

[Gasguru]