Hi

I have a question for you guys. Is it legal for a line voltage, programable wall thermostat for 240V baseboard heaters to break only one line? I have been told that this is not legal.

I purchased this commercially available line voltage thermostat, sold by Honeywell, that is rated for 240V ONLY, that only breaks one line of a 220V circuit. This thermostat is available for sale currently at Home Depot. My question is, is this legal for residental installations? if not, how can they be manufacturing and selling this thermostat in the United States???

Mike,
Only the disconnect is required to break both conductors. A thermostat is not required to break both sides of the line. If the thermostat has the word "off" on it, then it is a combination thermostat and disconenct and must then break all hot conductors.
See 424-20.
Don(resqcapt19)