Early this morning (3:30 AM) we were awoken to a smell of something that was like a combination of burning plastic and a central heating unti that was just turned on. We went downstairs and there was a haze of smoke in all rooms downstairs. We searched and searched and were looking for the source of it but could find nothing that was warm, hot, smoking or just on fire. I walked by a vent and noticed that they were blowing out warm air. I went to the thermostat that controls the unit and checked it. The fan setting was on AUTO and the Cool/Heat setting was on OFF. Although the unit should have been producing no circulation it was blowing out warm air and I am assuming the smoke that was creating the haze, that part I do not know for sure. It eventually stopped blowing for some reason so I turned on the thermostat to see if the unit was working and then switched the breaker to the unit off so no power was flowing through it. This worked too as the smell and smoke eventually diminished as we opened windows downstairs. The problem is this is really worrying me. I'd like to use and trust the unit especially with 90+ degree weather we've got coming this week but this could have been much worse than it was. We've got somebody that is supposed to come out and look at it but I was wondering does anybody know what may have happened or caused this? TIA
Good be bad thermostat? Some how it sounds like your furnace came on.... I'm assuming the unit is in the attic so do a test run while you are up there to see if the gas fires up.
Do not turn it on until you have it checked out. Have someone look at the blower motor, if fan is on auto and heat/cool setting is off it should not turn on unless there is issue with fan.
Do you have a zone system? A zone system could allow air to flow through the vent even if the thermostat is off (probably a bad damper).
