My propane sensor started beeping without the propane even being turned on, and I discovered that they only last about five years before replacement is required.  It's down at floor level in our 2013 model 177 below and left of the bath.  It is also the one main thing that runs battery's down over time, since it is powered directly from the DC and does not run off of an internal battery like the carbon monoxide and smoke detector's do.

Very simple to replace.  I ordered the exact same model off of Amazon for 59 bucks.  That is key to get the same exact model.

Took off the old one but the wires wouldn't come through the wall due to big factory connectors behind the wall hanging up on the small opening they cut.  So I just  cut the existing wires very long at the back of the faulty unit, stripped them, took the new unit and twisted with the stripped wires I cut, wrapped both with electrical tape, and slid the new working unit back on to the backing plate.  You have to take the backing plate off of the new unit and pitch it if you do it this way, and just use the one already mounted to the wall.  

It took maybe ten minutes.  

It is now working perfectly and is good to go for another five years.   No trip to the dealer and probably an hour's labor charge, required.  Anybody can do this maintenance repair.  

Originally posted by TheBum I got tired of always kicking the detector off the wall, so when ours failed, I bought one of the flush mount ones. I had to do some sawing on the paneling, but it's not difficult: I used the saw blade in my Leatherman Juice. For the wiring, I used crimped butt connectors.

Did the same thing.  Very happy with the flush model.

TT

Originally posted by StephenH Unfortunately, it is hard-wired and does not go through the fuse panel. It has to be to prevent someone from disabling it which would defeat the purpose of having it which is to keep someone from dying from CO poisoning or from going up with a bang if there is a propane leak.

That explains why I couldn't find the fuse!

I may just wire in line a SPST toggle switch with it and stuff it back into the wall with the wiring. At least that way you could disable the alarm when you determined there is no Propane or CO2 leak.

I know it's just sort of a typo, but it's a CO detector.  CO2, carbon dioxide, could suffocate you under almost impossible circumstances.  CO, carbon monoxide, is a deadly poison that can kill you in your sleep very easily.  In my opinion, overriding the always-on feature of these detectors is a very serious safety concern.  It's best to resolve whatever sets it off by opening the doors, cranking up the vent fan, or charging the battery than disabling it and risk forgetting to turn it back on.  You could wake up dead.

Also, as someone else noted, these detectors have expiration dates.  They have to be replaced about every 5 years.

TT

CO my mistake why I want to tag on a 2 I don't know! 

I would never disable any alarm unless I was 100% plus that all was good. The only reason I even contemplate being able to turn it off was is when I found out that if the DC voltage to it drops it will trigger the alarm because it senses it as a fault condition and not a Propane leak or CO build up. It tells you the alarm itself is at fault by a blinking LED along with the alarm beeping. Hopefully now with a new converter its all a non issue.