Another Electrical Question - Space Heater

Discussion in 'Energy & Fuel' started by Nancy Hart, Jan 10, 2019.

  1. Nancy Hart

    Nancy Hart Very Well-Known Member
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    @Frank Sanoica, or anyone... another electrical question.

    This is what they call a "milkhouse" style space heater. The bottom knob determines how hot it gets.
    milkhouseheater.jpg
    This is the inside.

    heater3.jpg

    My question is:. Where is the thermostat?

    Must have gone through at least a dozen of these heaters over my lifetime, and these are the best, when they work.

    They all quit the same way. Just quit. I figure it's got to be the thermostat or the switch. No?

    In the past, I just buy a new heater when that happens, but the quality keeps deteriorating. If it costs less than, say, $30 to fix it, I'm willing to give it a try.

    ps. I can get more pictures if necessary
     
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  2. Yvonne Smith

    Yvonne Smith Greeter
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    Those ARE great little heaters, and we have had them before, too. I am trying to remember if @Bobby Cole had to fix the thermostat on any of the ones we had; but he might have some information for you even if he hasn’t worked on one of these.
    I presume that you have looked on YouTube for milkhouse heater thermostat already ?
     
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  3. Nancy Hart

    Nancy Hart Very Well-Known Member
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    Just tried it again to make sure, because the word "milkhouse" is a newer keyword I discovered. I still don't see anything I haven't looked at already. Thanks, Yvonne.
     
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  4. Frank Sanoica

    Frank Sanoica Veteran Member
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    @Nancy Hart
    There are two control knobs, the top one appears to select fan speeds, with possibly one setting for "fan only", the rest for heat.

    The thermostat is a bi-metal flat spring, visible in the bottom picture built into the temperature control. An eccentric bears against the spring, placing more or less tension on it. The bi-metal structure causes the flat blade of the spring to bend, reacting in response to temperature change. Attached to the spring are a set of electrical contacts which "make and break" the current flow to the heating element and the fan, or in some designs the heating element only; the fan keeps running.

    In some designs the heat coil electric current flows through the bimetallic spring, in others the spring is electrically-insulated from current flow; this appears to be your case, but cannot be sure with limited view.
    Frank

     
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  5. Nancy Hart

    Nancy Hart Very Well-Known Member
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  6. Frank Sanoica

    Frank Sanoica Veteran Member
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    @Nancy Hart
    Some. From it, there appears only one electrical connection made; the other must be the grounded case of the heater. Unlikely the current itself flows through the bimetal, but unimportant, actually. I cannot deduce the entire wiring diagram without seeing the line cord connections.
     
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  7. Nancy Hart

    Nancy Hart Very Well-Known Member
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    Here's another one. That's it! The keyword was bimetal.

    [​IMG]

    Wiring

    [​IMG]
     
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  8. Nancy Hart

    Nancy Hart Very Well-Known Member
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    I got it!

    Looking back at my first picture, the neutral wire was not connected to the thermostat post. Didn't notice it until I took the wiring picture for you. Then I assumed it came loose when I took the thing apart, but it must have been already off inside. When I hooked that wire up, it worked!!!

    This is a really old heater. One of the first ones I ever bought. It weighs twice as much as the newest one. I like things you can take apart. :p

    (This can't be the reason the others quit, though.)

    Thanks Frank
     
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  9. Nancy Hart

    Nancy Hart Very Well-Known Member
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    Adding this video I just found, for the record. It might explain one of the others going bad.

     
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