markviii wrote:Why don't you just run the primary circulator off the triple aquastat? That way the circulator will not be able to run below the low limit setpoint. e.g. 160 degrees. I have installed two boilers in the last three months with this configuration, they run excellent.
I have a copy of the AHS Coal Gun Installation and Operator's Manual manual now, and the AHS S130 Coal Gun comes with a dual aquastat, not a triple. The wiring diagram shows that the dual aquastat on the AHS is a Honeywell L4081B. It shows one leg of this aquastat (the low temp leg I presume) going to the blower motor, and the other leg (the high temperature leg I presume) available for optional use as a high temperature level dump zone circulator initiator. I don't have a dedicated circulator on my dump zone, but rather I have only a 24 V normally closed zone valve.
Previously I had assumed that the Honeywell L4081B was an open on high temperature rise aquastat in conjunction with a close on low temperature aquastat (I.E., two separate aquastats, thus dual), so I wonder how having it open when the boiler reaches its dump temperature would start the dump zone circulator. It seems as if it should be shutting down the circulator instead, but I know this can't be right. Perhaps the blower is attached to the 'nominally' high level leg, and the dump zone circulator would be attached to the 'nominally' low temperature leg. ??? Obviously I have a lot of learning to do. Good thing that it comes fully assembled sans for the need to attach the feed hopper.