Hello, I'm hoping that somebody may have experience of how the following works in practice and I'd be grateful for any input.
To set the scene, the project is a 4 bed, 2 bathroom Victorian mid-terrace insulated to current Building Regs. We're looking to use a Viessmann 200-W 19KW system boiler with a 210 litre 200-V cylinder set up as a 4-pipe system, controlled using a Vitotronic 200 H01B weather compensation controller. Ideally, we would like 3 zones: 1. ground floor UFH (a Speedfit single room pack with its own adjustable blending valve and circulation pump); 2. ground floor rads; and 3. first floor and loft floor rads. The ground floor UFH zone and radiator zone are in practice open-plan.
Getting the weather compensation to work when there is more than one zone seems to be the main problem. If we compromise and combine zones 2 and 3 (the radiators) then Viessmann Techical have suggested the solution of using the optional sub-mounted mixer kit or, as we already have fitted the UFH valve/pump, an actuator and a brass bodied mixer turning it into a 6 pipe system. The Speedfit valve/pump would be wired into the actuator and I'm guessing the actuator then wired back to the boiler. I'm also guessing that there will be no other zone valves necessary and all wiring can be done at the boiler. Likewise, there will be no internal thermostats required and all controls for the two zones and the hot water will take place from the HO1B controller.
1. Is this correct so far? Have people had experience of this working satisfactorily in practice?
2. Would all of the rads have TRV's, save for the two bathroom towel rails?
3. Would it however be advisable/is it possible to keep a room stat for the UFH zone (to act like a TRV)?
4. I'm waiting for a price for sub-mounted mixer kit and/or an actuator and brass bodied mixer (they don't seem widely available). If it turns out to be unnecessarily expensive then what are the pros and cons on losing the weather compensation on the UFH zone and simply using a room thermostat and a 2 port valve to give separate circuit with individual control from the thermostat?
Thanks in advance.
To set the scene, the project is a 4 bed, 2 bathroom Victorian mid-terrace insulated to current Building Regs. We're looking to use a Viessmann 200-W 19KW system boiler with a 210 litre 200-V cylinder set up as a 4-pipe system, controlled using a Vitotronic 200 H01B weather compensation controller. Ideally, we would like 3 zones: 1. ground floor UFH (a Speedfit single room pack with its own adjustable blending valve and circulation pump); 2. ground floor rads; and 3. first floor and loft floor rads. The ground floor UFH zone and radiator zone are in practice open-plan.
Getting the weather compensation to work when there is more than one zone seems to be the main problem. If we compromise and combine zones 2 and 3 (the radiators) then Viessmann Techical have suggested the solution of using the optional sub-mounted mixer kit or, as we already have fitted the UFH valve/pump, an actuator and a brass bodied mixer turning it into a 6 pipe system. The Speedfit valve/pump would be wired into the actuator and I'm guessing the actuator then wired back to the boiler. I'm also guessing that there will be no other zone valves necessary and all wiring can be done at the boiler. Likewise, there will be no internal thermostats required and all controls for the two zones and the hot water will take place from the HO1B controller.
1. Is this correct so far? Have people had experience of this working satisfactorily in practice?
2. Would all of the rads have TRV's, save for the two bathroom towel rails?
3. Would it however be advisable/is it possible to keep a room stat for the UFH zone (to act like a TRV)?
4. I'm waiting for a price for sub-mounted mixer kit and/or an actuator and brass bodied mixer (they don't seem widely available). If it turns out to be unnecessarily expensive then what are the pros and cons on losing the weather compensation on the UFH zone and simply using a room thermostat and a 2 port valve to give separate circuit with individual control from the thermostat?
Thanks in advance.