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outside temp reading jumpy

I have a Lennox heat pump with the outdoor temp probe. It sometimes changes

5-10 degrees within a few minute period. I've replaced the telephone style connectors with wire nuts and had the service man replace the outdoor sensor while the unit was still warrantied. Today I have a new problem, the thermostat goes blank periodically for a few minutes then returns to normal. It's not just the display going blank because I hear an internal relay clicking when it dies and comes back to life. I went to all the wire connections and jiggled them but couldn't get the the thermostat to crap out. Any ideas on a solution to either or both of these problems. I'm out of ideas beside ringing out the wiring for shorts or breaks and replacing all the telephone style crimp connectors between the furnace, heat pump and thermostat with screw terminals.
Reply to
Jeff D
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Rip it out and start over..

Reply to
The King

After all.............. its almost always the thermostat. Bubba

Reply to
Bubba

Reply to
Jeff D

Here's another data point regarding the outside temp sensor. It is only erratic when the auxiliary heating is on, not sure what that interaction could be. What type of sensor is it anyway, thermocouple, rtd, thermistor, diode etc. Also it would be nice to get a print for the thermostat so I know what the maze of external wiring is connected to and their functions. The t-sat is a Lennox Signature Stat 81M28. I'm not a hvac tech, but was an industrial electrician for 30 years and worked on the wiring side of several hvac systems.

Reply to
Jeff D

Perry had written this in response to

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------------------------------------- Jeff D wrote:

The outdoor sensor tells the first stage heat to go off and the second stage to come on, The outdoor sensor needs to be on a T-stat wire by itself not tied in off the regular stat wire. Your tsat going off is either a bad Tstat or its losing power from the furnace. Hope it helps

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Reply to
Perry

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