Wet Exhaust Alarm: Cheap Insurance

Soon after I acquired Sunny Spells, I experienced the dreaded “exhaust muffler meltdown”. We were motoring out to a twilight race when the exhaust note suddeny changed and a lot of smoke was emitted from the engine room. We had the main up already so the engine was killed immediately and we continued the race. After the race we picked up a mooring under sail (lucky I was not on my own).

I established that a cooling hose had come off (a separate story could be told about the cause). The plastic water lift muffler had melted and a very simple fault had now resulted in a nasty repair job. Graham Friend, having decades of experience, had fortunately saved the engine by killing it instantly.

After a bit of “Googling” I found what appeared to be the perfect solution to avoid a repeat of the problem. Borel Mfg in the US makes an exhaust temperature alarm that claims to activate immediately should the exhaust temperature rise. It seemed to be reasonably priced at $89 and I ordered one straightaway – it arrived after about a week. Installation was simple enough – the most onerous task being the wiring. I chose to install the alarm below, but ran a repeater wire to the engine alarm in the cockpit.

Borel Wet Exhaust Alarm
Borel Wet Exhaust Alarm

I’ve often wondered whether it actually works – it’s just been sitting there for two years, making a quick beep whenever the engine is started… Recently, however, it finally paid for itself many times over, when a raw water impeller failed, and saved me a lot of hassle and expense. The engine and exhaust system was saved by the exhaust temperature alarm when a brand new raw water pump impeller failed. The story of that event is the subject of an earlier post…