I have a Wirsbo/Uponor hydronic heating system installed in 1993. Total of 4 zones, 1st floor, 2 zones of pex tubing 6 thermostats 2nd 1/2 floor baseboard heat zoned with Modine heater in 2 car garage, 3 stats. 4th sone a Weil-Mclain 42 Gal. Indirect Water heater with priority. Heat source is a W-M Nat. Gas GV 4 Series 2 Boiler. Had some noise from the boiler recently & our HVAC guy found the boiler circulation pump was locked up. Having some short cycling due to the original Wirsbo/Honeywell T86H thermostats. Replacing them with Honeywell CT87K stats. Found you wire them with red (power) to R & blue (yellow) to W instead of white. This powers the 4 wire thermal actuators & closes the end switch to call for circulator & boiler to run/fire. Considering adding a Tekmar outdoor air controller. Comments?