Heating the boat without a diesel heater.This basically means electric heat. The 439 has all A/C sockets on a single 15A ring/breaker. The micro wave is on the same ring. This means if we have a heater turn on then we need to turn it off while using the microwave.
We own 2 West marine 1500W heaters. They draw 10.3A maximum which is a long way from 1500W but that's another story. I can run both these heaters on the 15A ring at setting 3/4. This draws just under 7A per heater and results in more heat than one heater on 4/4 which draws 10.3A.
The water heater appears to be on its own 15A circuit also. This is shared with the battery charger I think which is a 60A unit. This means 6A is pushing full power. The water heater is plugged with a euro style plug in to a socket behind the galley couch back (beside the water manifold). I ran a heavy cable from there using a Euro to US adapter and this lets me run this ceramic heater instead of the water heater.
So, now we're at a 10A west marine heater and a 13A ceramic space heater. It isn't enough to keep the boat comfortable.
I realized that I'm not using half my boats power. The boat has 2 x 30A shore power cables. One is for the boat and the other runs the 3 A/C units on the boat. I unplugged the A/C shower power cable. On my Jeanneau, the cable is a 50A 125V ending. I had to buy a 50A 125 to 30A 125 pigtail. Then I purchased a 30A to 3x 15A 110V socket which is protected. I can run another space heater from that.
This puts me at a 10A, a 13A and another 10A.
Dedicated 400W engine compartment heater.
I also added a 400W 110V AC Caframo engine heater. This is a heater which turns on at 41F and turns off at 59F automatically. I installed it temporalily in the front of the engine compartment with zip ties for now. This should prevent the engine from having problems from the cold.