I live in WA which is about 2% less insane than Cal. In 1991 WA state came up with its own requirements for a system to emit freezing cold air into your furnace duct system since they thought the new insulation requirements were making houses to tight leading to "stale air". There is a "bathroom fan" with a timer that randomely turns on and brings air in from outside thru an 8" duct.
I thought I had disabled it on day one but now I think it must be the reason my Rheem Gas Furnace keeps turning on the blower fan in middle of the night when there is no call for heat. Just blows unheated air around for no reason and stays on presumebly for ever.
Figured maybe I had bumped a switch in my garage accidently or something? Anyone understand how the system works and how to shut it off permanently? I could simply unplug the "bath fan" motor but its possible there could be a damper somewhere that opens up letting cold air in?
Here is the STUPID: I looked up whole house fan system and the first thing I found was a multi page "study" (Of 31 Houses!!!) yeah THIRTY ONE HOUSES that they supposedly studied and determined that the systems were typically installed incorrectly. No one understood how they worked AND despite that the homeowners "like the system!!!!!!!!!!WTF!!!!!!!"
ANYHOW - I think there may be nothing wrong with my Rheem Furnace?? Heating works fine usually. Just fan turns on for no reason and seems to happen in middle of night like between 3-4 pm (not sure since I usually sleeping) I wake up and shut off all electricity to furnace and then turn it back on in am if its cold.
This all happens with the thermostat in OFF position. ANY IDEAS? Thank You