Why this system?
When we first purchased this boat, it was located in
Cleveland, Ohio. And I live in Chicago. I had my heart set on sailing it back home.
Across western Lake Erie, up the Detroit River, across Lake St. Clair, up the
St. Clair River, Northward up the length of Lake Huron, through the Straits of
Mackinac into Lake Michigan, and then down the entire length of Lake Michigan to
Chicago. A journey of about 732 miles. The only problem was, my window of
opportunity was at the last two weeks of May. And around these parts, the
weather is typically cold (40ish), windy and rainy. We were going to need some
type of heat while underway, to make it somewhat enjoyable. Even though it meant
that we would have to motor-sail at times, we needed the option of warming up. I
looked at diesel fuel units, and
actually liked them better because you didn’t have to run
the engine, but I didn’t have the time to install a
more complicated system. All in
all, I’m happy with it, and so is my
The three speed cabin heater Model 5H is also available from HeaterCraft .
5H - Heater
12V DC 3 speed
The unit was installed in series with the boat’s hot water tank line using 5/8” hi-temperature heater hose. The easiest place to tap into the hot water line was behind the engine, where the original hose made the turn to go towards the hot water heater located under the sink. Here you have a place where there's room to work, and can cap the lines immediately, with little or no fluid (antifreeze) loss. Only one of the hot water lines had to be cut, and it really doesn’t matter which one. Your direction of water flow will either be:
From the Engine – Hot water tank – Cabin Heater –
Back to the Engine
So, at the rear starboard side of the
engine, I spliced into the water line that was going to the hot water
heater. The two additional 15 ft. lengths of heater hose
ran around the back of the engine, and then along the port side up to the
compartment that contains the holding tank, where they enter the compartment
from below. Two 1 ¼”
holes will have to be drilled through the aft wall of the holding tank
compartment under the nav station. This allows the heater hose to be routed
to the heater installation area under
the nav station, and attached to the inlet port on the
(this photo looks at the
aft bulkhead in the holding tank compartment. It's important to bleed the
system to ensure there is no trapped air anywhere in the system. The black water
line you see in the picture is there to provide a "high point" in the system
where I added replacement anti-freeze to top off the system and to make sure
there was no trapped air. The black "t-eed" line going off to the right is a section of hose
that is capped off at the other end. The purpose here is to stand this hose
straight up and create a "high point" in the system to make it easier to bleed
all the air out.)
The return line attaches to the outlet port of the radiator, and runs back alongside the other heater hose back to the rear of the engine compartment, where it is attached to the other end of the line you cut. From here it uses the existing hose that goes to the hot water heater, and then flows back to the engine pump, where the circuit begins again.
Now, you need to get all the air out of the system. After all, two 15 ft. lengths of empty heater hose, not to mention, the radiator on the heater itself, which was empty, have been added to the system. The procedure is simple. All you need is point in the system that is at a higher elevation than everything else, including the engine. So I installed a tee in the line that fed into the heater unit, and attached a 5 foot length of heater hose that I could cap off. Once the system is intact, and all clamps tight, uncap this line. Then hold it up high, and using a funnel, fill the entire system from this point, letting the air bubble up and out the hose. Taking the radiator cap off the engine also helps trapped air escape. Start the engine, and after a few minutes, check the level again, and repeat until the level at the radiator cap stayed consistent. Then filled the reservoir overflow tank to the proper level, and you're finished.
I mounted the unit under
the nav station, and it draws fresh air for the blower from an area
at the top rear of the cabinet that I built for it. I chose this location to
avoid drawing air from the sometimes smelly bilge area. I also considered the area forward of the water
tank, under the settee on the starboard side, but I didn't want to draw any
intake air from the bilge area and blow those aromas all around the
cabin. Plus, I didn't want to give up
any of my storge areas.
Here is a diagram of the new plumbing.
The heater works
like a charm when motoring. When we brought the boat from Cleveland to Chicago in the early spring, The outside
air temp was in the 40's, but the heater kept the cabin at a luxurious 80
degrees! And it provided a place to shake off that bone-chilling cold!
Notes from 2 years after...
I've had this installation for 2 years, and been through through some hot,
humid 100+ days, and it hasn't really added any additional heat to the
cabin. Even though hot water is flowing through the heater core, very little
is dissipated into the cabin. In fact, to gives you some basis for comparison,
it radiates less heat than the hot water heater. Not enough to
Last modified by Mark Elkin, Sunday, February 06, 2005 . Copyright © 2005 by Catalina 34 International Association. All rights reserved.