Engine Overheating Alarms

We have now installed 2 heat monitoring systems from Aqualarm.net, www.aqualarm.net, both monitored from the same panel. The following details the steps:

1. Cooling Water Flow Detector cat no 13209

Aqualarm says: “Monitors Marine Engine Raw Water Flow to prevent engine damage due to overheating. Activates a visual or audible device immediately whenever raw water flow is stopped or impeded. Is a two wire, non- polarity switch that is Normally Closed (Normally Open available) and opens at 1.5 GPM of raw water flow. It stays open until flow slows or ceases and then actives any audible or visual boat alarm. It is design for Low Flow application such as smaller engines or generators.”

Install by inserting in line ensuring that the detector is oriented correctly. It will only work one way. Run electrical connection to Water Flow and Exhaust Panel (see below). We also required a barb to hose adapter. Tip: so that detector can be removed, if possible don’t shorten intake tubing. Keep a tube joiner handy to detector to rejoin tubing.

2. Wet Exhaust Overheat Detector cat no 20250

Aqualarm says “The Exhaust Overheat Detector is a two terminal,non polarity, amp normally open detector that closes when wet exhaust temperature reaches 200°F and activates a visual and/or audible device.”

Comprises a metal band placed around the exhaust tube immediately aft of the engine with wiring again run back to the Water Flow and Exhaust Panel.

3. Water Flow and Exhaust Panel cat no 20358

4. Electrical: The final step is to wire the alarm to the starter of your engine and the panel.

Project Cost: $186.40, including post from the USA, 7/12/12

Footnote:

We were fortunate to be under sail when the engine failed and therefore easily able to drop anchor in Shoal Bay, in sight of the Port Stephen’s Marine Rescue Station. In no time we were towed to nearby D’Albora Marina where the mechanics from Nelson Bay Marine Chandlery and Mechanical Services quickly fitted a new Vetus water lock and impeller. The cause of the engine overheating was our failure to turn on the seacock after a week on the marina. In our very early morning rush, a fundamental routine water check was overlooked. Club Marine Insurance does not cover damage as a result of seacock being turned off, so in that respect we were lucky that the engine itself had not been destroyed. We no longer turn off the engine water seacock when cruising. Another tip, keep your keys to the engine on the seawater seacock when you do close it. Having said that, a closed seacock is not the only way water flow can be impeded especially when cruising in /near cities with plastic bags and other pollutants.

Happy Cruising!

MCantrell 29/5/13

Published June 2013 Mainsheet, Coastal Cruising Club of Australia