Block heater fire

[Fair Well]

Don’t know how many of y’all use your block heater is this time of year. Here in this part of Texas where I am located I use mine not to keep the engines from freezing but to keep the moisture and humidity down. While working on re-plumbing the boat yesterday I touched the port Engine and noticed it was not warm. Upon further investigation found that the plug going into the block heater under the fuel filter had caught fire what kept it from burning the whole damn boat up I do not know. Breaker never tripped. You can see from the photos that it actually got hot enough to scorch or blister the paint on the bottom of the fuel filter. Just food for thought something some of y’all may want to add to your weekly checklist while going over the boat engine room. I’m going to change out both of my block heaters and put them on arc ground fault circuit so hopefully this cannot happen again.

 

[racclarkson@gmail.com]

Thanks for passing this along. What brand are they?

 

[llldks]

I also reside in Texas and use block heaters. The mechanic installed them With butt connectors in line about 5 feet from the heating element. After about 2 years, the wires felt extremely hot and registered 195 degrees with the infrared thermometer. The mechanics responsive was both disappointing and inadequate so I replaced the butt connections with terminal strips and now the temp registers 110, which I assume is conduction from the heating element. I feel I avoided a potential fire. Beware of butt connectors. My bad for not using a marine electrician.

 

[Fair Well]

Thanks for passing this along. What brand are they?

I am looking into what brand they are. I know or it appears anyway that they have a thermostat because there is a sensor on the upper water manifold and the block heater is installed below the water pump. As soon as I find a brand or a replacement that looks similar I’ll post it here.

 

[Jammin']

I put mine on timers. My mechanic suggested that instead of running them in the middle of the night, I run them around 6:00 in the evening. I questioned him why run them that early when the temperature is lowest just before dawn. He said that there's no one around the marina to see them sparking and smoking in the middle of the night.

 

[KPTIM]

When you install the new ones use Di-electric grease on the plugs.
These kind of faults typically happen from the connections being corroded.

The breaker did not trip because it was not drawing too much current you may of just had a high resistant connection at the plug because of contact corrosion.

 

[oscarvan]

The breaker did not trip because it was not drawing too much current you may of just had a high resistant connection at the plug because of contact corrosion.

A HUGE problem in the marine environment and a majority contributing factor in boat electrical incidents. Reason to NOT skimp on wire and connectors in this business.