240V hydronic heating pump?

[John Arnold]

This afternoon I inspected a run-of-the-mill 80-90 year old row house, with hot water heat.
I couldn't get the boiler to kick on, until I traced the wiring to a double pole 240V breaker (FPE Stab-Lok, but that's another story), which was off. Against my better judgement (it was really hot and my brain wasn't firing on all 3 cylinders) I turned on the breaker and the boiler fired up and the pump started running, sounding fine.

I tried to read the plate on the pump motor, but no luck.

Has anyone ever seen a residential boiler pump wired to 240V??

[Steven Saville]

Very unlikely the pump is 240v on a residential system. One possibility is that the boiler circuit is only using one leg of the double-pole breaker. You never know what a homeowner has done over the years. If the system is a very old gravity system, the circulator may have been added years later and placed on a separate circuit and the 2p breaker was used to control both circuits. A lot of strange stuff out there <BG>
I guess you could check the voltage at the pump to confirm.

[James Duffin]

Grundfos makes some small 230 volt pumps...

Grundfos - Circulation Pumps and hot water recirculation energy efficient pumps (http://www.plumbingsupply.com/circpump.html#fmci)