I have a hydronic system from Webasto on a bene 473. It worked great last winter (and so far this one) in Boston. The model is the DBW2010 with 45,000 BTUs.
Although I don't have the system running through the water heater (the water heater only has one coil, for the engine), I added a heat exchanger
for the engine
, so when we motor
I can keep the whole boat dry and warm (this is the best).
I think 45,000 BTUs is a little bit too much for us most of the time, but as full time liveaboards, when we are -20C for a week, this system keeps us totally unaware of what's going on outside.
When we are at anchor
, this system is really power hungry so if you are going to use it make sure you have enough power. I replaced the nozzle at the beginning of this season because it clogs up pretty easily, smoking like crazy and burning way too much diesel
. This is easy to do and cheap
(the nozzles on amazon are around 5euros.
If I weren't planning on staying where I am for years, where the marina freezes for about a week or two, I'm not sure I would install this system. It's expensive and it takes a fair amount of space and weight. I see on your profile that your location is Denia. I'm currently in Valencia (I'm from here), and I have trouble imagining needing this system with such a wonderful weather
We have used our reverse cycle to see when it stops performing well. As long as the sea water stays over 4C (~40F) the system keeps pumping out heat. This, an extra space heater, and the best invention ever, an electric
mattress cover, would be plenty. Sure it would be expensive to run, but when I crunched numbers comparing heating Vs. diesel
heater, it would take 4-5 years with the Webasto to break even.
Good luck and enjoy Denia!