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.

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.

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 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.

Thanks
B

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?

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.

Thanks
B

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.

Thanks
B

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.

Double! 220 total off the fuse box but who's to say where else the wire goes and whether 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.

A few comments that may or may not help beyond Labmans' help:

Model numbers and pictures will be helpful.

A 240 volt heater, if connected in the US, needs a 2 pole stat.

A 120 volt heater uses a single pole stat.

The wires that are "jumped" may be bypassing the stat, therefore not shutting off the power to the heater at all.

Either the heat is on or off, nothing in between.

Can you isolate the wires that run from the stat to the heater?

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 programmable. 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 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 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 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

This "jumper" concerns me. Where exactly is it? Why get a new heater? Seems this one there is fine, as it won't shut off.

Since the heater is 240 volt, really should have a double pole breaker , to conform to national electric code, unless your local area waives this requirement.

I don't get the mold issue, what the heat is suppose to do. If the room gets to temperature, the stat should open and shut off the heat, period. Unless the stats are built with no true OFF setting, so that the heat will come on if the temp gets to the lowest setting of the stat.

Any chance of a pic of the jumper?

Quote:

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Originally Posted by tkrussell

Since the heater is 240 volt, really should have a double pole breaker

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Sorry I meant thermostat, not breaker, in this statement.

Oh... there are two poles on the breaker... but only half available voltage going to the thermostat & heater. (couldn't tell you where the rest is going)

The single pole vs double pole is referring to choices in thermostat style. A double pole has an 'off' setting whereas the single pole has min temp setting of @50 degrees, thus the room will 'always' be heated to some extent. It is optional. Some people, with vacation homes swear to the double pole because they think it makes it less appealing to rodents. As a landlord in a wet climate I want the single pole. I don't think it's a matter of code... it's simply a matter of preference.

The heater unit itself is rated as 220v... the thermostat claims to operate under either the line voltage is the lesser... 110v... thus, according to the heater instructions, which are quite good, the heater should barely function, losing 70% of efficiency and barely get warm... it is hot... since it's wanting much more juice then it's getting it should not be getting hot. The thing that concerns me is that it's not getting cool. It needs to be a 110v to conform to the amount of power it is receiving, however, the issue of it not 'switching' off and honoring the thermostat/room temperature concerns me. I do not have any faith that the 110 unit will correct the problem. There must be something else going on... but I'm clueless what.

My tenants are getting impatient with me I'm sure.

Is that clearer?

I did verify the thermostat connection, voltage, line vs load connections at thermostat, voltage at heater, connections at heater (white on white, black on black), all appears well.

Any ideas?

Any possibility that the new thermostat is faulty?

I agree with Labman,either something is wrong, certainly weird, or this is something I am not familiar with , keep the eff, at 70%. I never heard of that.

Your getting much better with detail, I hope your tenants realize the effort your putting into trying to get this resolved.

Unless I can see some sort of diagram showing how something like this works, such as the other rooms that do work as you explain, I am stumped.

Is this a regional thing? Due to the high moisture content? And special stats? All the single pole stats I am familiar with have an off setting.

Maybe it's the jumper, I keep harping on that but not getting any info or pictures, I have to think that is a possible problem, otherwise, beats the hell out of me.

But we will keep trying.

Anyone else reading this and have any ideas?

And yes, of course, any device can be defective,I hope you have checked for that first.

I am assuming all devices are working properly.

There are only 2 ways you will get this resolved.

1 Give tkrussell all the details he has asked for and then wire it up just like he says.

2 Hire an electrician to do it.

My choice would be #1. There may be legal aspects favoring #2.

If I can make a suggestion... strongly consider suggestion #2 from labman.

You should consider hiring a licensed sparky for this. In most jurisdictions I've seen, it will be illegal for you to work on the electrical of your rental unit if you're not licensed.

Good point Cobra, hopefully everyone that posts a question here reads the Read This First Sticky note, where that topic is addressed.

OK... I broke down and called in an electrician.

At least he didn't make it look easy.

He explained something about 220 power that I didn't quite get. Something along the lines that the thermostat is only grabbing at 110 (half) of the power/potential for the unit and interupting the flow... somehow?? Big question mark left kind of not filled but that the thermostat won't actually see the full potential so no source of concern on that.

There were several problems the bulk of them rested in the fact that the wire coming out of the wall at the heater unit was compromised at the heater casing... the insulation had been nicked... little tape there all well.

The problem still not resolved he took the front off the heater to give it a thorough looking at claiming there wasn't 'continutity' in the unit... the power wasn't traveling back and forth properly.. found where the bundle should travel out of the heater coil through the frame into the box where the wires connect had been wedged backward and rubbed itself raw against the frame (manufacturer's defect)... straightened that out, channeled it through properly and wrapped it with tape and wallah... all is well.

There was potential also that I had hooked up the thermostat backwards... the guy did a lot of mumbling... so I wasn't real clear on that. The extra wire that I had determined was some kind of jumper was most likely the additional voltage to run the unit at full power and would then be the line to the heater vs the hot line from the box... (? Not sure I stated that clearly... ) Thought I'd drop a line what happened in the end in case anyone was curious... it boiled down to examining every connection, every point of entry, every stretch of wired to find the problems.

I had this problem. The heat stayed on even with the thermostat set very low. It only went off when I turned the thermostat to "off". The thermostat I bought (Honeywell) had 4 wires in it, 2 black and 2 red. The black wires were pushed into the thermostat when I took it out of the package. The red ones were exposed and those were the ones I connected to the wires in the wall. That caused the heater to stay on. Once I connected the black wires from the thermostat to the black wires in wall, everything worked great. I know, dumb on my part, but at least I didn't have to call an electrician to fix it.