By: BWood On: Sun Dec 09, 2012 8:42 am
Hello All,
As always, i learned a lot here but nothing beats a pro. I found a great HVAC guy, he helped me set up the new coal boiler with a 3 speed circulator into the return line from the oil boiler, pumping towards the Chappee boiler, with isolator flanges for easy replacement. The supply runs out to the existing zone valves with a 1"T into the oil boiler supply. The caloristat controls the circulator on the coal boiler creating a thermal loop that keeps the oil boiler hot. When the thermostat calls for heat upstairs, the zone valves open and the heat runs upstairs. He placed a clamp on aquistat on the return to trigger a power closed special order zone valve located in a bypass loop that jumps the supply around the zone valves. In the event the coal boiler goes over 200 degrees, it opens the bypass loop which dumps the heat into the entire house. The valve also fails open in the event of a power loss, allowing the entire house to be heated in a power loss from the analog caloristat on the coal boiler.
Thanks for your help!
Woody