Zone valves for unvented cylinders

[Dan Robinson]

And my unanswered question?

 

[ALEC1]

I would just wire the boiler through the overheat stat dan.

Regulations are not policed anyway, they are not even researched properly, they just a knee jerk reaction from a few middle aged men who don't take the time to understand technology from other countries....

This regulation makes no sense, but it did with a cast iron boiler...technology has moved on quite a bit since then!

 

[Andygasman2010]

Worcester specifically state that the two port valve supplied with an UV cylinder can be omitted when using their integral diverter valve kit. So long as the overheat stat is wired-up to the permanent live to the boiler.

This would of course contradict the MIs of an UV cylinder, so which MIs would you go with?

They both comply with G3.

In the case of the OP I'd say that if a 3 port is used AND the overheat stat is wired to the permanent live of the heat source then that's OK.

 

[freeoil]

I installed a Panasonic ashp with supplied diverter valve .Honeywell 2 port supplied with cylinder was repurposed for one of the heating circuits.As long as dhw fails closed on 3 port its cosher. Heatgeek & Urban plumber on yt explains indepth. I also queried this with the Panasonic rep.

 

[muggles]

I installed a Panasonic ashp with supplied diverter valve .Honeywell 2 port supplied with cylinder was repurposed for one of the heating circuits.As long as dhw fails closed on 3 port its cosher. Heatgeek & Urban plumber on yt explains indepth. I also queried this with the Panasonic rep.

Given that this thread is more than 11 years old, I suspect they've sorted the issue by now