The heating system on Issuma consists of two drip-pot diesel heaters. The pilothouse is heated by a Dickinson Lofoten heater, which is also used for cooking (though most cooking is done by a gas stove/oven). The forward part of the boat is heated by a Dickinson Alaska heater (see previous blog entry).

Fuel for the heaters is gravity-fed from the daytank, through a fuel
filter/water separator. The drip-pot diesel heaters will not run if there is water in the fuel. A little water in the fuel will result in it boiling loudly as it enters the combustion chamber, and the heater might stay running, but with a lot of water in the fuel, the flame will go out, and the regulator needs to have the water removed from it (there are no drain plugs, so the way I've done this is to suck it out with a copper tube).

Between these two heaters, the inside temperature can be about 25 degrees C higher than the outside temperature, or about 20 degrees higher if it is windy.

This works well down to about -10C/14F (and not so well at -20C/-4F).

Previously, a wood stove was used. This put out a decent amount of heat, but had to be tended every hour or two, so, over the course of 24 hours, didn't put out as much heat as a diesel heater did. The wood stove was more suitable for heating when there are several people aboard, to share the task of tending the stove.