replacement for honeywell rotary mixer valve and actuator in system with AQ6000

[Sapper1958]

I have a gas fired central heating system with, what was pretty state of the art, Honeywell AQ6000 controler when installed in 1992.
The system has worked well for many years but the rotary mixer valve V5069D seems to have become too stiff to move by the actuator M676C and the plastic arm that drives it has broken.
The valve seems to be discontinued.
Is there an alternative that I can replace it with.
Or is it possible to service the valve? dismantle, clean repack replace any seals etc.
The boiler Ideal Mexico Super 2 CF120 is still working well (although I know not as efficiently as a modern condensing one) and seems simple, reliable and long lasting so I don't want to change that.
Are there more modern controllers with weather compensation that I could replace the system with?

 

[Dan Robinson]

Modern equivalent would be Evohome and the hm80 controller.

Not many out there that understand it though.

 

[Sapper1958]

Evohome looks an impressive system but only works with modern condensing boilers it seems.
I was looking for a simple fix to extend the life of my present system: not a full replacement system at present.

 

[Dan Robinson]

It doesn't only work with condensing boilers. But if you are trying to keep the old system running then buy a new Valve body and actuator. Honeywell or esco do them.

It won't be like for like so some pipe changes will be required.