worth


  #1  
Old 12-02-04, 08:20 PM
tworth
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furnace warms the room 2 degrees then blows cold - why?

When the Honeywell Chromotherm III thermostat is set to, say, 70 degrees on heat, the room heats from its starting temp of 66 degrees to 68, or from 67 to 69, etc., then starts blowing cold air and never reaching the desired temp, eventually dropping the temperature of the room to below where it started and continuing to blow colder and colder air until the unit is turned off for a minute or two, at which time it can be turned back on and would start blowing warm air once again. I'd like to try to repair it myself (Trane gas furnace with a pilot ignition knob and no readily visible limit dials/switches) if I could.
 

Last edited by tworth; 12-02-04 at 08:29 PM. Reason: bad title
  #2  
Old 12-03-04, 04:47 PM
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It does not sound like a thermostat problem. It sounds like an airflow problem. I'm not positive, but there may be a lack of airflow and the furnace overheats and locks out. If there is a control board with an LED somewhere on the furnace, it may blink an error code that would help you figure out the problem. Look in the documentation and see if it makes reference to the diagnostic LED. If not, you can explore the unit a little. I would be inside the blower compartment possibly under a cover. Check it out before you turn off the power or you will lose the trouble code.

Ken
 
  #3  
Old 12-05-04, 12:14 PM
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i agree, airflow probably the cause. a high limit switch tripping would cause this, have the heat exchanger checked too
 
 

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