How do you know it was never 104 degrees or higher where the smoke detector was installed? The temperature isn’t necessarily uniform and steady. There can be currents and hot spots. Yes, it’s common for them the false alarm in garages.
Yes, this is still the most reliable way to monitor for fire in garages and attics.
System Sensor 5600 series heat detectors are not powered. They are purely mechanical.
The rate-of-rise elements in them can be tested with a hair dryer or heat gun and are self-restoring.
The fixed temperature elements are 1-time use and can not be tested. But there are couple ways to check that it hasn’t already been tripped.
- They have a a post-activation indicator in the form of a collector. When the
detector is activated, the collector drops from the unit, making it easy
to identify the unit in alarm. (I can’t seem to find a picture of this to share) - You can check the output terminals with a multimeter or continuity tester. If the fixed temperature element hasn’t been tripped then you should see infinity ohms or overload (no continuity) on the meter.
If you test the rate-of-rise element you must be careful not to come close to the fixed temperature element’s threshold. If you trip the fixed temperature element then you have to replace the detector.