I saw a review of hot water tanks that was published in Norway, but it did
not cover the common units available in North America.

Has Practical Sailor or anyone else done one that cover Force 10, Seaward,
Raritan, Isotemp etc?

I no longer get PS, so if anyone has results of testing, could they
summarise?

Some concerns:

- materials - Some have aluminum tanks and heating coils, others S/S or a
combination of the two, others glass lined steel. (How will aluminum coil
stand up to salt water - I will be using raw water cooling)
- Type of insulation - PU foam, Fibreglass, rock wool - how long does water
stay hot?
- Outer cover - galvanised, S/S, Plastic.
- Hot/cold mixing valve - is it needed?
- Wattage - some are 750W and some are 1500W regardless of tank size!
- Dimensions - need to get it into cockpit locker where it will consume a
lot of space!

I would like to have a custom unit made to fit the space, but suspect cost
may be excessive - has anyone done this?

Thanks,

GBM

PS did a review in early '99 - I remember it well because it panned
the Seaward and came out a few weeks after my boat was "sealed" with a
Seaward in it! (Or is that a "Sealand", I'm not sure now. I'll try
to track down the issue.) The major test they were doing was heating
with the AC and measuring the cooldown rate. As bad as ours was
rated, it isn't that bad, since the largest use of shower water is in
swimming weather, when its not so important to be really hot.

The Sealand has an aluminum tank. So far, that hasn't been a problem,
but I have the required galvanic isolator.

GBM wrote:
I saw a review of hot water tanks that was published in Norway, but it did
not cover the common units available in North America.

Has Practical Sailor or anyone else done one that cover Force 10, Seaward,
Raritan, Isotemp etc?

I no longer get PS, so if anyone has results of testing, could they
summarise?

Some concerns:

- materials - Some have aluminum tanks and heating coils, others S/S or a
combination of the two, others glass lined steel. (How will aluminum coil
stand up to salt water - I will be using raw water cooling)
- Type of insulation - PU foam, Fibreglass, rock wool - how long does water
stay hot?
- Outer cover - galvanised, S/S, Plastic.
- Hot/cold mixing valve - is it needed?
- Wattage - some are 750W and some are 1500W regardless of tank size!
- Dimensions - need to get it into cockpit locker where it will consume a
lot of space!

I would like to have a custom unit made to fit the space, but suspect cost
may be excessive - has anyone done this?

Thanks,

GBM

I have a generic concern about water heaters that use engine coolant as
the heat source: a pinhole leak in the heat-exchanger tubing inside
the water heater would permit coolant to mix into the hot water, and
you might not know it until the leak became severe. Ethyl glycol is not
my favorite intoxicant!

Anyone aware of any instances of this (presumably, there would be a
lawsuit)? Are my fears unfounded?

Capt Ron

wrote:
I have a generic concern about water heaters that use engine coolant as
the heat source: a pinhole leak in the heat-exchanger tubing inside
the water heater would permit coolant to mix into the hot water, and
you might not know it until the leak became severe. Ethyl glycol is not
my favorite intoxicant!

Anyone aware of any instances of this (presumably, there would be a
lawsuit)? Are my fears unfounded?

Capt Ron

Of course for any coolant to flow into the water system, the pressure
difference would have to be in the right direction... what is the
pressure in your engine coolant loop (hint: see your radiator cap), and
what is the pressure in your water system?

bob
s/v Eolian

One of the marine water heater operating manuals that I read on line said
that if antifreeze comes out of a faucet, the heat exchanger should be
replaced! I also read somewhere that non-toxic antifreeze (polypropylene
glycol) was not recommended for some engines.

Pressures of water and engine coolant pumps cannot be known for every boat,
so I would think there is a good chance the coolant side is at a higher
pressure than the domestic water, esp if the domestic water pump is switched
off.

So, I think you have a good point. I suppose S/S or Cupro-Nickel coil would
help, but with stray currents, anything can happen and probably will.

GBM

I have a generic concern about water heaters that use engine coolant as
the heat source: a pinhole leak in the heat-exchanger tubing inside
the water heater would permit coolant to mix into the hot water, and
you might not know it until the leak became severe. Ethyl glycol is not
my favorite intoxicant!

Anyone aware of any instances of this (presumably, there would be a
lawsuit)? Are my fears unfounded?

Capt Ron

The PS tests were mainly heat retention ability. The original Isotherm with
the orange foam insulation came out on top. Not sure how the newer
stainless jacketed would rate. Second was the Heat Transfer Products Super
Stor.

We use the big HTP heaters in our commercial properties and they have proven
to be excellent performers so I went with a 12 gallon Super Stor. It has a
well insulated stainless tank with heavy plastic skin and is built to the
same standards as their commercial tanks. I added a Watts N170 thermostatic
mixer valve so it will output the water at a constant 120F. Theoretically
with the tank at 180F and supply at 80F the thermal valve will extend the
usage by more than double.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"GBM" wrote in message
...
I saw a review of hot water tanks that was published in Norway, but it did
not cover the common units available in North America.

Has Practical Sailor or anyone else done one that cover Force 10, Seaward,
Raritan, Isotemp etc?

I no longer get PS, so if anyone has results of testing, could they
summarise?

Some concerns:

- materials - Some have aluminum tanks and heating coils, others S/S or a
combination of the two, others glass lined steel. (How will aluminum coil
stand up to salt water - I will be using raw water cooling)
- Type of insulation - PU foam, Fibreglass, rock wool - how long does
water
stay hot?
- Outer cover - galvanised, S/S, Plastic.
- Hot/cold mixing valve - is it needed?
- Wattage - some are 750W and some are 1500W regardless of tank size!
- Dimensions - need to get it into cockpit locker where it will consume a
lot of space!

I would like to have a custom unit made to fit the space, but suspect cost
may be excessive - has anyone done this?

Thanks,

GBM