Electric baseboard heating problem

[Gm1234]

We have a bedroom in attic that we seldom use. But with holiday houseguests it is getting use. But, the electric baseboard heater is not working.

We have fuse panels. This particular room's heating is not identified, but perhaps it shares a circuit with another heater? Anyway, I removed all fuses and checked each one. No bad fuses.

The heater is controlled by a wall thermostat - It has white and black wires coming to it - The thermostat breaks the white wire only, the black wire really just passes through. I checked voltages - nothing across the white & black on either side of the thermostat. But from either black or white to ground (the box), I get 110v. Just is case, I changed out the thermostat for a spare, but no change.

At heater, it is the same - no voltage between the incoming wires, but 110v to ground from either side.

Questions:

- If I see 110v to ground from black & white, why don't I see 220V across these conductors?

- If I see the 110v to ground, does that mean that I do have power to the heater?

Any suggestions as to how to further troubleshoot this problem?

Graham Ontario, Canada

[Edwin Pawlowski]

Each wire should be 110 to ground, 220 if you contact both of them. The thermostat is breaking just one wire. If it is the stat, you can get heat by twisting the two wires together.

[Gm1234]

"Edwin Pawlowski" wrote

This is what I would have thought, but the puzzle is that I get the 110v to ground, but not 220v across the hot conductors. Changing thermostats made no difference, so unlikely a thermostat problem.

Graham

[dpb]

That indicates both "hot" wires are connected to the same phase somewhere -- either at the fuse box or at some other junction box, somebody made a wiring mistake and got both of them on the same side.

[RBM]

Assuming the heater is 240 volt, it appears that either you do have one bad fuse in the circuit, or the two feed wires were inadvertently wired to the same leg in your panel. Find the origin of this circuit in the panel and determine that you have 240 volts on the load side of the two fuses that feed the circuit

[mm]

Is this a permanent 220v installation, or a baseboard style space heater?

>

[mm]

BTW, has it ever worked? How long have you lived there?

[Big Al]

It indicates one leg is open. The 120 is passing thru the element.

Al

[dpb]

,,,

Depends on where he's measuring, but possible, yes. Thought OP indicated directly across feeds, but if not...

[Gm1234]

"mm" wrote >

Good Question! and the answer is YES it has always worked in the past, but we had not checked it this winter until now.

This should answer most of the suggestions (I appreciate them!) - We have lived here for 30+ years - The panel has not been modified during that time nor the bedroom's wiring.

I understand how the voltages would be as measured if somehow both hots were being fed from same phase - But at a loss to know how this could be.

We did have some bathroom rewiring done this past summer, but it should not affect this area. But you never know!

Graham

[Gm1234]

"dpb" wrote

I measured zero volts across white/black hot wires at feed to wall thermostat and also at feed to heater itself. At both places, I read 110v to ground from either hot wire.

Graham

[indago]

061231 2102 - Gm1234 posted:

Disconnect the power to the heater at the panel, and then disconnect the wires at the heater. Then, reconnect the power to the circuit at the panel, and turn the thermostat all the way up. Then, check, with your voltmeter, across the two wires at the heater. Also, check each one to ground. The one that shows 0 to ground is the one that is giving you the problem. If the system was working before, it should work now, except maybe a fuse has blown, or, when the remodel was taking place, the wire got cut somewhere along the line.

[RBM]

He should first check to see that he has 240 volts on that circuit at the panel

[mm]

Hard to believe it used to be connected to the right phase, and it moved during the summer.

That is undoubtedly the reason. How, I have no idea.

You didn't answer my previous post. Is it permanent heating or space heating? More importantly, do you know that it is 220, or might it be

110?

If it were 110 and the heat is on, but the white is broken some place between the thermostat and the fusebox, then you would get 110 at both the whiite and black between ground, but 0 between white and black.

Although white is usually neutral and at ground potential, when the white wire is broken, the 110 potential will flow from the black through the appliance to the portion of white closer to the appliance. It's all at the same voltage when there is no current flow.

Come to think of it, this would all be true with 220 also. In 220 only 110 comes from each conductor. Maybe the fuse or breaker, or wire, for white or black, is blown, tripped, or broken. That would account for your symptoms.

[Gm1234]

OK, thanks for input - Problem is resolved!

Because heating circuits are not clearly labeled on fuse panel, I did not know which one the problem heater was on. Today I pulled all heater fuses (They are in double-fuse holders with hinged cover to prevent removal of individual fuses). I now did not have 110v to ground at the wall thermostat. We then plugged the fuseholders in one at a time until the 110v re-appeared. So we found which circuit the heater was on..

I tested problem circuit fuses by using resistance meter across the brass forks of the fuse holder and it showed continuity for both pairs. But, when I removed the fuses, one was bad! This despite it showing no sign of having blown - fuse strip was still intact - problem must have been internal.

Anyway, a new fuse solved problem - I guess next time I should remove each fuse from holder, but still don't understand why testing across the "prongs" showed no problem!

Existing main panel is Amalgamated Electric Cat No 200-4240 combination service entrance/panel 200A with 19 double fuses and one large fuse pair for range. There are two small sub panels with 6 breakers each that serve areas that were re-wired at one time. There is another breaker panel in the garage also fed from the main panel.

Would it be worthwhile considering upgrading main panel to a breaker panel? Rough cost?

Thanks for all the input guys!