Two stats for two floor UHF system

[Mike5286]

Hi all. Just had two floors of ugh. Two seperate heat miser controllers, each having 5 programable stats and a twin cable back to the boiler for the Ls and Lr. Wired up ground floor. Works fine. Stat signals controller, pump starts, electronic valves open efor ufh ect. Volt free contacts switch incoming Ls to Lr which fires boiler. All perfect. Now the second floor is the same, but I am just checking, does the Ls and Lr from the upstairs controller run in parallel and just piggy back the Downstairs? In essence two volt free contacts in parallel?

Thanks in advance1

 

[SimonH2]

Yes.
If either (or both) are closed, the boiler runs. The boiler only stops when both are open.