Unconventional heating arrangement

[tmus1]

So basically what I have is a combi boiler supplying heating for two properties and splitting the heating for the two properties using a 3 port valve, I’m using two single channel programmers to control a room stat for each house but am having trouble working it out in my head. is it possible to have both controllers independently control the heating without changing it to an s plan (ps spoken to plumber s plan is out of the question, would have been so much simpler)

 

[Leesparkykent]

So basically what I have is a combi boiler supplying heating for two properties and splitting the heating for the two properties using a 3 port valve, I’m using two single channel programmers to control a room stat for each house but am having trouble working it out in my head. is it possible to have both controllers independently control the heating without changing it to an s plan (ps spoken to plumber s plan is out of the question, would have been so much simpler)

Sounds like a bodge but yes it's possible.

 

[tmus1]

I don’t like it I don’t think a 3 port valve will last as long if it’s being used this way. Any wiring diagrams anywhere? manufacturers instructions are pretty unhelpful, it’s the nc and no stuff connecting to the valve that throws me the rest I can deal with

 

[ruston]

I would be concerned about safe isolation in two separate properties with automatic switching.

 

[tmus1]

As there’s a door joining the two properties and it’s the same Electrical supply from DNO I don’t have a problem with it the 2nd property is just an Annix which they intend to holiday let

 

[Timbo]

You will need an off signal from the primary circuit thermostat.
S plan would be simple to install and wire. Use programmable wireless thermostats.

 

[Leesparkykent]

It's really not much different from a communal boiler system. I doubt you will find a diagram. It's pretty simple though if you follow a Y-plan diagram and think of the HW side being the second heating zone. Anything that's connected to port B of the three port will be acting the same as HW on a y-plan diagram. You will need normally open of the room thermostat and CH off from the programmer of the side that's on port B to connect to the grey of the 3 port valve.

Think as the programmer for port b as HW on and the room thermostat for port b as the cylinder thermostat when looking at a Y-plan diagram.

If you've already wired it I hope you have enough cores at the thermostat for port B as you need the connection from CH on, neutral, switch line from normally closed to fire boiler and normally open connected to CH off and the grey of the 3 port...If you've wired it in 3core and earth you don't have enough cores.

 

[Octopus]

As there’s a door joining the two properties and it’s the same Electrical supply from DNO I don’t have a problem with it the 2nd property is just an Annix which they intend to holiday let

Does the annex have its own cu ?

 

[tmus1]

Thanks that’s all I wanted to know you top dog!!