Image of furnace fan blower

thermostat disc.

As opposed to probe thermostat.

Image of thermodisk fan control dial settings. These are more common on older furnaces than new ones that will use a control module to control the fan.

Bottom image of fan thermostat thermo-disk.
 Used on furnaces where there is not enough room for a conventional probe type limit control.

Package that thermostat came in. This one was purchased from Aireco in Maryland, you can also get them from Grainger or Johnstone Supply. For a list of supply houses click here.
Top view of electric furnace sequencer side view of sequencer used in heat pumps with electric backup
Images of electric heat sequencers.
Carrier part number HN67QC 005 Ths one has two sets of switches (1 to 2, 3 to 4) and two timing functions to minimize use of the second heating element.

  1. Blower: usually a squirrel cage centrifugal air moving device. Will move large volumes of air relatively quiet. Will use less energy with more back pressure.
  2. Fan: a paddle type air moving device used where noise is not a major consideration. Will use more energy with more back pressure.
  3. Combustion blower: A blower used on high efficiency furnaces or oil burners to move combustion air. usually 1/20 to 1/6  horsepower.
  4. OEM: Original equipment manufacturer.
  5. Horsepower: 746 watts
  6. KW Kilowatt (1000 watts) or 3400 BTUs per hour
  7. RPM: revolutions per minute.
  8. Service factor: the extent to which a motor can be safely overloaded beyond its name plate ratting without over heating.
  9. Air over horsepower: The rating of a motor assuming air flow through the windings usually as a result of the air moving device.
  10. SAE: Society of Automotive Engineers.
  11. Ton 12,000 BTUs per hour of heating or cooling
    This page will be updated soon
 Good Luck Scott
If your heat pump forms ice outside in the heat mode click here.
If your air conditioner or heat pump ices up in the cooling mode click here.
If you have water leaking problems with your air conditioner  click here to solve it.
To ask us about heat pump problems click here.
To ask us about other heating system problems click here.
To solve oil burner problems click here.
 Any other questions feel free to contact us by any of the means below. good luck Scott.

    If you were looking for Ice Machine repairs click here.

For solar energy information click here.

To solve other air conditioning and cooling problems.

Written By:  Scott Meenen N3SJH of:
Specializing in Mechanical, Controls and Electrical Modifications Of
Heating, Air-conditioning, Refrigeration, Cold storage,
Ice Production and Food preservation. Anything having to do with Heat and Energy.
Serving MD, DC, and Northern VA.
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                 This text written by: Scott Meenen * G & S Mechanical

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