Baseboard Heater stays on.

bigfish · #1 Nov 15, 2007, 03:57 PM

I have a baseboard heater that stays and gets really hot when the thermostat is turned all the way down. It is a single pole thermostat and brand new. I thought the new thermostat would correct this very problem.

The baseboard itself was brand new just last year.

It seems to go up and down but does not honor the thromostat at all and does not ever appear to go completely off.

The single pole thermostat replaced a double pole. The double pole was only hooked up on one side, so I imagine that it was operating as a single pole.

This is a rental unit and I would prefer to have a single pole as I do not want any part of the unit to be left entirely without heat.

labman · Nov 15, 2007, 04:27 PM

If it is a 240 volt unit and you have all 4 wires at the thermostat, it would be better to use a double pole thermostat. That way, when the heat is off, everything is dead from the thermostat on. With a break in one leg of the circuit, no current flows, no heat, but everything is hot and able to short.

I would compare the power rating of the heater and thermostat. A likely cause of the problem is the heater drawing more power than the thermostat can handle and the contacts weld. The solution is a higher power thermostat.

bigfish · Nov 15, 2007, 07:36 PM

Hey Labman,

There are only two wires at the thermostat. One appears to be jumpered... believe it's off to supply power to the bathroom heater on the other side of the wall.

I believe the thermostat and the heater are designed to work as 120 or 240.

I've seen other similar questions but they all seem to be addressing mulitple heaters. This is one heater and one thermostat.

Could the wires be 'reversed'? I replaced the thermostat about a month ago when the tenants complained that the heater didn't go off and got really hot. I believed that the thermostat was the problem. It was an old thermostat. I wired it the same way and the problem continued. The old thermostat was a double pole but only one pole was wired... the other pole was not connected to anything.

The single pole is preferred as it is a rental unit in the pacific northwest where you do not want a room to be held without heat for any period of time or mold will grow on the walls. I have single pole hooked up in total of 4 units and several in this unit and they all work fine. Something isn't quite right with this one. Not sure what. I have an appointment to look at it on Saturday morning. I was going to just go buy another thermostat and give it a run... but I'm not convinced that that will address the problem.

thanx
b

labman · Nov 15, 2007, 08:28 PM

If you only have 2 wires, than you may as well use a single pole thermostat. What about that jumpered wire? If the thermostat is switching 2 heaters, then it needs to be rated for more than the total load. So add the ratings of the bathroom and other heater, and make sure the thermostat can handle both.

3 Wires? Is this wired up with conduit?

bigfish · Nov 15, 2007, 08:31 PM

no.... it's jumpered before entering the thermostat. This thermostat only controls one heater. The heater in the bathroom has a thermostat "on it" and works fine. I was guessing where the jumper went... there are only a total of two wires to attach at the thermostat.

looks like I'm on my own... will not be able to check response tomorrow.

thanx
b

bigfish · Nov 19, 2007, 02:32 PM

ok... the low down. The thermostat is rated for either 110 or 220. The heater is 220 and it turns out that the line is actually drawwing 110. So I've ordered a 110 heater. The problem that I'm having in me head is that the troubleshooting guide for the heater installation claims that if you run a 220 heater on a 110 current that the heater will not get very warm and run at about 70% efficiency. This is not the case. The heater gets quite hot and stays warm-hot all the time. All does appear to be wired correctly. Any thoughts on this issue welcome. The new heater should be in in the next week. Had to special order from the hardware store.

thanx
b

labman · Nov 19, 2007, 02:55 PM

Something is funny here. Starting at breaker panel, does the circuit have a single or double pole breaker? How many wires run to the heater, and how are they connected? I still don't understand about that third, jumpered wire. In a 240 circuit, the 2 hots will both be 120 above ground, but 240 to each other.

bigfish · Nov 19, 2007, 03:03 PM

double! 220 total off the fuse box but who's to say where else the wire goes and whether or not it ever ran 220 to this heater. 110 is getting there.

I think the third/jumper wire is neither here nor there. Looks like just one leg of the potential 220 runs to the heater. Going to treat it as 110 and go with it. But the thermostat does not appear to be regulating the heater. I'm hoping that maybe it's the regulator on the heater itself which is malfunctioning and this may be causing the over run (I doubt it). I did not have a hex wrench so could/did not attempt to adjust the thermostat. Really focused on trying to pin down some issue causing it to run on all the time. Was surprised to find the line was 110.

bigfish · Nov 19, 2007, 05:56 PM

thank you for coming into this tk...

I could get the model #... the heater and thermostat are 'King', both purchased in the last year from standard stock at Lowe's (right off the shelf). The thermostat is basic generic, not programable. And I had understood that it was a matter, really, of whether you wanted the thermostat to have an 'off' position whether you chose a single or double pole. I chose single pole being in the Pacific NW, not wanting my tenants to turn off the heat, close the door and call me 6 months later about the mold on the walls. I have a total of 16 heaters in 4 units, running off of 12 thormostats and have replaced about half of them in this same method/manner. This is the only one that's being 'Bad'... it is also the only one that is 110 as far as I know.

I'm not sure how to go about isolating the wires. I suppose I could pull the jumper, although since it is soddered and clipped, I hesitate... it suggests to me that it was done by a pro and I don't want to tinker with it that much. I have seen this 'method' in both units at the thermostat when replacing thermostats which suggests to me that they are original. The structure was built in mid-60's. (If that means anything to you). And I wouldn't have any trouble believing that the replaced thermostats and heaters were both original to the period.

When I throw the bundled fuse (two knobs bound as one) it goes off. (ya, a little weak in my electrical back ground). I could disconnect the jumper... but it's jumped off of the hot side and runs on elsewhere... not sure what I might gain from that knowledge. I did test the bathroom heater suspecting it was running off of the jumper... but it is 220, so that is not the case... it must have it's own source.

The only sign of any electrical 'modification' in the unit is that someone cut in and installed (poorly) a light/ceiling fan fixture in the livingroom.

I'm really at a loss what to do. I've got the new heater coming in... but I don't think that hooking it up is going to solve the problem.

your thoughts welcome!

b



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