Central air and heating turns on by itself

Gabriel8642 · 03-09-2013, 01:31 PM

This may seem strange but it happens. I have central heating and cooling system in the attic. The thermostat is on the wall with a wire going up trhough the ceiling. I switched the thermostat to off and the settings of both blue heating and red air conditioning is all the way to the left or below 50 degrees. What happens is that once in a while the system goes on by itself. It blows cold air. I took the thermostat out taking the four wires out, thinking it was not working; but even then the system would go on by itself. So, I turned the breaker off at the panel board. Unfortunately, the same line is connected to the bedroom lighting. So, it is not the thermostat to blame. So, why is the system turning on by itself ? Can I put a switch somewhere so I can shut it off without disturbing the bedroom ? What is there in the motors assembly in the attic that makes the unit go on by itself ? Thanks for any advice.

HVAC1000 · 03-09-2013, 01:36 PM

when you had the wires out of the stat did you let any of them touch?

Houston204 · 03-09-2013, 01:38 PM

Inspect around your furnace for an air cycler.
It looks like a white thermostat.

http://www.aircycler.com/productline.htm

yuri · 03-09-2013, 01:39 PM

that or some raccoons/squirrels got into the attic and chewed some of the tstat wires. watched enough Billy the Exterminator shows to know that can happen. U may need to replace the wire from the tstat to the attic unit as it may have a short in it.

old_squid · 03-09-2013, 09:46 PM

Does just the blower in the attic unit come on? How long does it run?

03-09-2013, 01:31 PM	#1
Gabriel8642 Newbie Join Date: Feb 2013 Location: Los Angeles, CA Posts: 5	Central air and heating turns on by itself This may seem strange but it happens. I have central heating and cooling system in the attic. The thermostat is on the wall with a wire going up trhough the ceiling. I switched the thermostat to off and the settings of both blue heating and red air conditioning is all the way to the left or below 50 degrees. What happens is that once in a while the system goes on by itself. It blows cold air. I took the thermostat out taking the four wires out, thinking it was not working; but even then the system would go on by itself. So, I turned the breaker off at the panel board. Unfortunately, the same line is connected to the bedroom lighting. So, it is not the thermostat to blame. So, why is the system turning on by itself ? Can I put a switch somewhere so I can shut it off without disturbing the bedroom ? What is there in the motors assembly in the attic that makes the unit go on by itself ? Thanks for any advice.

03-09-2013, 01:36 PM	#2
HVAC1000 Experienced HVAC Tech Join Date: Dec 2012 Location: Northern Colorado Posts: 188	Central air and heating turns on by itself when you had the wires out of the stat did you let any of them touch?

03-09-2013, 01:38 PM	#3
Houston204 Member Join Date: Oct 2009 Location: Texas Posts: 581	Central air and heating turns on by itself Inspect around your furnace for an air cycler. It looks like a white thermostat. http://www.aircycler.com/productline.htm

03-09-2013, 01:39 PM	#4
yuri Hvac Pro Join Date: Nov 2008 Location: Winnipeg, Canada Posts: 6,737	Central air and heating turns on by itself that or some raccoons/squirrels got into the attic and chewed some of the tstat wires. watched enough Billy the Exterminator shows to know that can happen. U may need to replace the wire from the tstat to the attic unit as it may have a short in it. __________________ "Cut it twice and it is still too short". To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

03-09-2013, 09:46 PM	#5
old_squid Member Join Date: Oct 2012 Posts: 155	Central air and heating turns on by itself Does just the blower in the attic unit come on? How long does it run?

Central air and heating turns on by itself