I have a hydronic heating system with a relatively powerful B & G circulator pump. This pump has a relay that is controlled by the furnace electronics; if there is no power to the furnace, there's no power to the pump.
This makes it tricky to purge air from the system via the technique of using the city water filler, a circulator, and the drain, thus bypassing the boiler.
I would like to be able to use the circulator when the furnace is off. I thought that the best way to do this would be to install a junction box with a UL listed DPDT switch (e.g. a Leviton 1286) that switched the circulator's feed from the normal furnace wiring to an electrically isolated hard-wired appliance cord of sufficient gauge that I would plug into a different circuit.
Can anyone think of problems with this?
Is this against the electrical code, or will it not apply so long as the appliance cord is not plugged into the different circuit.