2 zone setup

MasonC
MasonC
edited March 2021 in General Questions & Topics
Hi - looking for some clarity on how I can do this please.

I have the Ideal Atlantic boiler, Tado Extension Kit and 2 wireless smart thermostats. I have radiators round the house and underfloor heating in the kitchen split by a 2 port valve off the boiler to each set.

How can I control them independently and control the 2 port valve with this setup?

Answers

  • You cannot have two wireless thermostats in a Tado system. Your solution is to have the extension kit controlling one of the two-port valves and a wired thermostat controlling the second two-port valve.

  • Hello! There’s just one 2-port valve in the setup. The 2 port valve is just staying open. How do I get this being controlled as right now radiators and underfloor are on when I turn 1 zone on.
  • If you have just the one motorised valve then you cannot have two independent heating circuits. With one valve you will have a primary circuit that is fully controlled and a sub circuit that can be turned on/off, but only when the primary circuit is active.

  • @GrilledCheese2 To your first answer - does that mean that it becomes a cascaded system? that is the wireless thermo controls the action of the pump and the second zone is a slave zone of the first? - Which also means I can't use the radiator thermos in the second zone without having the first zone running as well?

  • Sometimes the hydronic zones can be cascaded. It often happens when a home is extended, creating a second zone for one or two extra rooms. In the answer I gave above I assumed the hydronic zones were independent and would be operated independently by the Tado thermostats.

  • @GrilledCheese2 - thanks for the response.

    My missing link is how is the boiler turned on? if there are 2 independent zones then Thermostat1 OR Thermostat2 will need to turn both the boiler AND the respective valve on, no? The available documentation I have read isn't really clear on this but according to my understanding an additional wired Thermostat(2) will actuate the valve more or less independently of the boiler activity. It also makes for pretty messy decentralised wiring.

  • GrilledCheese2
    GrilledCheese2 ✭✭✭
    edited October 2022

    @Coachman A typical S Plan system works as follows:

    1) A thermostat wanting heat will turn on a 2-port valve for the hydronic zone.

    2) The motor in the 2-port valve rotates and when it reaches its end stop it activates a small switch.

    3) The valve's switch is connected to the boiler's switched lived terminal using what is commonly known as the 'orange' wire.

    4) A boiler only has one switched live terminal so multiple orange wires are connected together. E.G Four zone valves means four orange wires are connected together. 230V on one or multiple orange wires will start the boiler.

    5) When the boiler switches on it will initially switch on the circulation pump. Once the water is circulating the boiler will ignite and start to heat the water.

    In short there is no direct connection between the thermostat and the boiler for S-plan. A basic Combi system is a lot simpler. The thermostat is connected directly to the boiler and a wiring centre is not required.

  • @GrilledCheese2 - super !!! thank you very much, simple when you know it.