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Tekmar RTU 54 Replacement
I have a Tekmar 371 Control System with 054 RTU's in each of the 5 zones. All RTU's are currently set low for summer (12oC). One zone is calling for heat even though room temperature is 20oC plus. I switched the RTU with another zone and that (new) zone immediately called for heat. I assume RTU is the problem. The RTU is Tekmar 054 which I believe is discontinued. Can you advise what a suitable replacement would be.
Many thanks in advance.