Worcester Bosch 8000 Thermostat Modulation with Zone Valve Headache

[mattwaddy]

So the current plan is to have a 40kw 8000 with two zone valves, one to cover the downstairs wet underfloor heating which will have room thermostats and call the boiler via the wiring center. The second zone valve for upstairs radiators as a single zone with one thermostat. I'd thought about using the Bosch EasyControl for that purpose but my heating engineer says it wont work with needing to open the zone valve. Is there any thermostat that will work in this setup and still support modulation or will we need to settle for an on/off only thermostat? I really wanted to maximise boiler efficiency. Any help appreciated as the install starts next week

 

[muggles]

It'll have to be on/off, or go for a boiler which actually supports multi-zone modulating controls. Anything with decent OpenTherm will do it

 

[mattwaddy]

It'll have to be on/off, or go for a boiler which actually supports multi-zone modulating controls. Anything with decent OpenTherm will do it

Any boiler suggestions? I thought the 8000 was a pretty good boiler, I had looked at the Viessmann 200

 

[muggles]

Am I right in thinking it's a combi you're after?

 

[mattwaddy]

Am I right in thinking it's a combi you're after?

Yeah sorry it would be a combi