More webasto issues lead to adopting other measures

I'm continually getting trouble with my Webasto 5500 which won't stay on. It shutdowns randomly with either a F1 (mostly) and F2 code. The diesel tank is full with fuel from auto diesel stations. The trouble now is that the worst of the winter is still to come and my boat isn't winterized as I want to use it and live on it part time during this time.

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.

Winter arrives

Well,
Winter came. It was down below zero F during the last weekend and I got to test out the heating setup on the boat. I have a dealer installed Webasto 5500 on the boat. The reverse cycle heat that I was using isn't working now that water temperatures are 37F which is too cold to make any heat. So, these are turned off now until the water gets above 40f again.

We knew the Webasto does not heat the boat uniformly. Most of its heat exits in the port AFT bedroom, the main toilet, the rest goes between the starboard AFT bed room and the main cabin. The forward toilet and the forward berth get almost nothing.
So, the forward cabin went down in to the low 30s. The main cabin is around 50 and the rear are around 55F. The engine compartment was in high 30s. I did remove both side inspection panels for the engine allowing some heat to enter the engine compartment.

I want to stay on the boat and this isn't enough heat for me. So, I purchased two Westmarine 1500W space heaters (99 bucks ea), one for fwd berth, one for main cabin.

These pull 10.6A at full power and 6.5A at 3/4 power. The Jeanneau has a single 15A circuit so I can't run both at 4/4 or run a microwave at same time either, its all on the same 15A circuit. I run them both at 3/4 each which is about a 13A draw,

The Westmarine heaters are not putting out the heat on the box, 10.6A is around 1166 watts, not 1500W.

Anyway, with the heaters and the Webasto, the boat is managing to keep 65-68F in the main cabin and 40s in fwd cabin so thats working for me. I sleep in the starboard AFT cabin which is cosy. The boat is warm enough to be in a t-shirt when its single digits outside.

BTW, opening the engine compartment results in a good cold draft (not good) from the rear of the boat in the main cabin. I ended up just removing one panel rather than both panels from each aft berth.