Odd carbon monoxide alarm

[Riwright]

We survived a severe windstrom in the California desert last night. During the worst of it the CO alarm went off. I was puzzled as to why. The detector is a combination CO/Propane detector that sits next to the sink near the floor. It gives different alarm patterns for the CO and Propane, this pattern was for CO.

My first guess is that it was something happening with the water heater. The water heater in our unit is under the sink, very close to the alarm. We had no heaters of any kind running, the stove was off and the frig was running on A/C. No generator, no vehicles nearby. It's the only thing I can think of that has a flame.

The wife reported a smell like chicken soup.

I shut the water heater off and opened the place up. No more alarms. Nothing like this has happened before. Water heater is running normally today.

We also have a second CO alarm in the sleeping compartment, that one was silent.