mystery 240 volt baseboard problem

[sidneyh]

i'm doing a side job right now and this lady has a baseboard heater that isn't working but apparently has in the past. i checked the lines coming in and and it showed 120 to ground on both wires and 0 between the two. i found the breaker that is feeding that heater (and likely others) and it was correctly placed in the panel on seperate phases. i opened up a few jb's trying to find where the wonky splice is and found nothing, but by the time i got back to the heater, it was on. i checked the voltage again and had 240. i didn't touch a thing. 10 minutes later the heater was off with 0 volts between the lines. that's the extent of it, havn't done any real troubleshooting yet, but i'll be back there in a week or so. any thoughts? thanks

[Bill190]

One of the hots is losing its connection.

Did you test the power to the baseboard heater with it still connected?

If yes, then what was happening was that the still active hot was feeding back through the heater element to the other side. This is why you got 120V to ground on both wires.

Is there a switch or wall thermostat which controls this baseboard heater? (Hint: If they lady says no, look for one anyway just to be sure.)

[Bill190]

P.S. My elderly neighbor asked me to come over to see what was wrong with the lamp beside her chair which was not working.

I went over, tried switching on the lamp and screwing in the bulb - nothing.

I got another lamp which was working and plugged it into the same outlet. Nothing.

I asked my neighbor if a switch controlled that outlet. "No!" She says.

Then I flipped on a switch next to the door and the lamp came on. I told her that the switch controlled that outlet and she needed to turn on that switch for the outlet to work.

She said "It didn't do that before!" Then she said "Well who turned it off?" (She lives alone and has lived in that house for 15 years.... )

[sidneyh]

thanks bill. i pulled the breaker and found it to be corroded and oxidised. i chipped off some of the crap and put it back in but when i flipped the breaker it started arcing and sparking. i pulled it out again and saw that the bus was pitted and damaged and unable to hold a breaker in properly. bad news. we'll change the panel next week. thanks again