on a boat.
||Please send any
comments to me.
This page updated:
From Michael Rich on IRBS live-aboard mailing list:
I replaced my hot water heater during the fall and used
Defender's Atlantic water heater and went from 6 to 12 gallons. The existing
one was 20 years old and was a mass of rust. The water heater's measurements
were a little larger than the specs from both Defender and Atlantic since
the base is somewhat wider than the rest of the heater. I ended up having
to cut a larger hole under the aft stateroom berth, but that was easily
fixed with a bigger piece to cover the hole. Make sure you can get the
larger heater through the hatch. I could get it through the hatch but
couldn't get it aft to the aft stateroom. I had to lower it with the mizzen
halyard through the coach roof. The distance or run from the engine coolant
to the inlet is about 15 feet. Be sure to use good exhaust hose for this
run from the engine to the heater and back and orient the water heater the
right way or you won't get all 12 gallons of hot water. Also you might want
to check the wattage of the heater element to make sure your breaker can
handle it. I learned from my mistakes on the installation but it sure is
nice to have more hot water. The engine should run cooler with the increase
in the distance and cooling effect of the heat exchanger being a greater
From Shaun Sweeney on IRBS live-aboard mailing list,
about installing a hot water heater in the engine coolant loop:
For what it's worth ..., I would:
1. Move the heater.
2. Insulate the lines running to and from the heat exchanger.
3. Install a circulating pump in the line.
4. Install a coolant filter in the line.
The circulating pump can be of the 12 volt variety or 110 volt. I've used
both without problems. I think the 12 volt is made by Johnson but as long
as it's made for constant use you'll be fine. The 110 volt (which I use
now) is a German product commonly used for hot water heating systems in houses.
The coolant filter can be picked up at any good truck supply shop and comes
in two varieties - cheap and expensive. The cheap ones are recommended for
starters as you'll find they plug up quickly if your engine is not new. The
more expensive ones help keep the pH level and are selected based on your
tests of pH. You won't find a diesel truck on the road today without a
coolant filter so why don't we find them in more boats?
By the way, in addition to the pump ensuring that your coolant is going thru
the filter, it also serves to reduce the time it takes to get hot water
after you start the engines, and, keep the chill off your engine(s) when
you're connected to shore power.
From Ken Mayer on IRBS live-aboard mailing list:
Our water heater of 17 years also died this year -- we've yet to cut it up so
we can remove it -- but we have no plans of replacing it. We decided that once
we're living on the hook, running the engine to heat the water was not an
effective use of diesel: The water tends to cool down very quickly once you
start to use it, as cooler water replaces the hot water in the heating vessel.
We also do not take showers in the head, instead we have several 1.5 liter
solar showers and take our showers in the cockpit (or use dockside
facilities). We do like hot water though, especially for cleaning up greasy
dishes and washing our hands. We found a 2 liter "air pot" -- those coffee pot
things that use an air pump to force the water out, so you don't have to pour
-- at a local restaurant supply store for about $50. It fits nicely in the
galley and can keep water warm for about 24 hours (so we just boil an extra
pot in the kettle in the morning).
From Mike Folkestad on IRBS live-aboard mailing list:
BoatU.S. (acting as insurance agent) wants me to remove my Wolters LPG demand
gas hot water heater for 'safety' reasons. This unit has performed
flawlessly for 12 years. It is vented to the outside. Has anybody on the
list had experience with this type of heater and is there one available that
is 'insurance company' approved ? It is the NFPPA (National Fire something or
other) that is raising the objection to these appliances. There are units
that are approved by the Canadian Coast Guard and ones that are listed with
the American Gas Association that are available. ...
From Lew Hodgett on IRBS live-aboard mailing list:
It is probably the NFPA, which is essentially a watch dog organization
for the insurance industry. These are the same folks that bring you the
NEC (National Electric Code).
If you have an AGA approved unit (it will carry an AGA seal, probably
stamped on the device), you should have no problem with the NFPA.
- In tropics, instead of a water heater, use a deck-mounted
flat tank painted black and plumbed to the galley.
- Consider replacing the water heater's insulation with better insulation ?