I have a brand new Slant Fin boiler, oil-fired, with two separate zones (Main Living Area and Basement Den), each with its own Taco circulator (brand new).
The circulator and tstat for the basement zone are wired into a Honeywell RA89A switch; both zones are controlled by a Honeywell Acustat.
When the main zone tstat calls for heat, the tstat for the basement zone will function if bumped up simultaneously, with the boiler calling for heat; however, if the tstat for the basement zone is bumped up to call for heat by itself, it will not fire the boiler. The appropriate circuator does come on, but just runs and runs without the boiler kicking on.
Does the problem lie with the RA89A (older), or perhaps with the Aquastat (brand new) or it's wiring?
I'm stumped, all advice and/or suggestions are much appreciated. Thanks and best,