Aquastat Controls (also posted on the main wall)

NCPABill

All,

Thanks for all of the past posting - the reading has really been informative. I haven't seen anything specific to my issue, so I though I'd put it up for all to weigh in.

I am installing a wood fired gasifying boiler (Biomass 40) with a 500 gallon storage tank. The boiler has its own circulator, controlled by the boiler "brain." This will essentially circulate heated water to the storage tank while the fire burns wide open. The only change would be if the return water temperature gets above 190 degrees, then the draft fan shuts down and the fire smolders.

My house piping has its own circulator which will be controlled by the room thermostats / zone valves. I think I should be able to hook this up as it is a simple change over from the gas boiler.

I'd like to use the gas boiler for freeze protection (should an emergency ever arise) only. I am thinking that I would use an aquastat at the water tank to sense a low water temperature (say 100 degrees), which would turn on the gas boiler until the tank reachers a set point (say 130 degrees). In my mind, I could run 120 to the aquastat, then to the gas boiler. I have a Honeywell 6006C on hand I'd like to use.

Would this idea work, or what am I missing? Admitidly, I'm very weak with controls, and for the life of me, I can't seem to ever fully understand the theory behind wiring.

Thanks in advance for your time. I know it is valuable, and sincerely appreciate the help.

Bill