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Water Heater

16K views 18 replies 13 participants last post by  albrazzi 
#1 ·
Hello everyone,

I have a an old Raritan 6 gallon water heater on my Seidelmann 299. I want to replace it with new heater that has a heat exchanger so I can hook it up to my Yanmar engine. Initially I looked with at the Raritan, but I also looked at some cheaper "squre models" such as Kuuma.(Defender.com)
It's half the price of the Raritan... Is the quality making up the price difference? Also, because it's a square shape instead of cylindrical, does it make it withstand less pressure? Thank you and GO VOTE. :)
 
#2 ·
The amount of pressure on a boat's water system isn't that high, so the shape of the tank shouldn't be an issue. Some of the price difference is paying for the brand name Raritan... some of it is probably in the quality of the product.
 
#3 · (Edited)
The amount of pressure on a boat's water system isn't that high, so the shape of the tank shouldn't be an issue.
.... But the rated PSI of the Pressure Relief Valve can be. I replaced the water pump that feeds my Isotemp water heater which from the obscene prices of the Isotemp I saw when I had my issue must put it at the 'top of the line'. As long as you don't do what I did... which was blindly or dumbly if you wish, just pick out the 'best' / highest PSI pump I could find without checking the 'fine print' in the water heater manual for the Max PSI allowed. I don't remember the exact numbers off hand but it was something like - Water Heater max allowed PSI was 47 and I fed it with a 50 + PSI pump. The relief valve handled it for a while summer before last but then it started 'hammering' - release-hold-release-hold into the drain hose making a horrible racket. Looking back on all the things that went on that spring I think the valve 'took it' for a while because I had a very small slit in a hose elsewhere that finally blew. After that there was no stopping the hammering until I read the fine print in the manual ...... duh.... and re-replaced the pump with a 45 PSI pump. Problem solved.
 
#4 · (Edited)
Water Heaters

There are basically only a few marine HX/Electric water heaters made.

Atwood, Force Ten (Kuumha) & Seaward's - These square water heaters look to be all made by the same company and re-badged. They all feature a stainless steel JACKET but an ALUMINUM tank! Buyer beware!

At a minimum this is cheesy and misleading. Think about it, you have steel, aluminum, stainless, brass and perhaps copper in your HX/engine/domestic water circuit. Aluminum is the LEAST noble of these metals..!!! I would not pay big bucks for these corner cutting, inferior products if you value your dollar! I have had one fail on just about every Catalina I owned..!!

Superstor - Superstor's are made by Heat Transfer Products a REAL water heater company who also sells water heaters to plumbing and heating wholesalers and to the trade under the Superstor brand name. They also private label some tanks for manufacturers of boilers & heating equipment so they can offer a matched set. The tanks are 100% 316 STAINLESS thought the HX is made of "cupronickel" which is just a coated copper coil. They have had some issues with HX's on some residential "indirect fired tanks" in the past but those issues seem to be behind them.

Isotemp/Isotherm - These tanks are very well built tanks and also made of 100% 316 STAINLESS. The HX, jacket and tank are ALL 100% stainless (no dissimilar metals other than the electric heating element). Isotemp water heaters are made in Italy and are manufactured under the Indel/Webasto umbrella. By a decent margin, and in my opinion (opinion based on 13 years spent as an independent manufacturers rep the hydronics industry selling this type of product) these are some of the best built marine electric/HX water heaters made and NO I don't yet own one but will WHEN not IF mine fails I will..

Quick - This is an interesting new Canadian made tank with a plastic or 304 stainless jacket and a 316 internal tank and HX. Don't really know much about them and distribution is limited. Quick is a decent company to deal with for windlasses and such so they would probably stand behind the product.

Torrid - This Seattle based company produces a glass lined tank with a tin plated copper HX and powder coated STEEL jacket! If you know what's good for you DO NOT buy a steel jacketed anything that will sit in a damp bilge!

Raritan - This round water heater features a rust resistant plastic jacket but a STEEL glass lined tank similar to the Torrid. Glass lined tanks don't last well in the residential world so why would they last in the marine environment? 316 Stainless will out last a steel glass lined tank every day of the week..

There are other tanks out there such as the Vetus "tank within a tank design" but the list above are the most commonly sold & used. There ARE differences in water heaters. The Superstors & Isotemps are worth the money! The "square" tanks are not...
 
#5 ·
So, basically, you're saying get an Isotherm/Isotemp if you have to buy one. If you can't get an Isotherm/Isotemp, get a Superstor. :) Thanks for the heads up and summary Mainesail. :)
 
#7 ·
QL marine - Volvo Penta

SOLARE came with a new QL Water heater installed by the PO. I'm quite impressed with it as it provides almost instant hot water on shore power (15 minutes or less) and it keeps the water hot for well over a day.



The QL water heater is available in 20, 22, 30, 40 and 60 L (5-16 gallons) sizes. The tank is made completely in acid resistant stainless steel, which makes it very suitable for the marine environment. The design and materials also meet the highest sanitary requirements. The QL water heaters are insulated using polyurethane foam, a material that contains a lot of air and thus reduces heat dissipation. The insulation is extra thick on the upper panel and helps keep the water hot long after it has been heated. Thanks to the QL water heaters innovative compact plastic casing and integrated brackets these units occupy less space than equivalent cylindrical models with separate fastening brackets. They also feature greater security, like five sturdy fixing points with no sharp edges.

QL is using electric heating elements in incoloy which have a much longer life compared to copper and have the great advantage of not being damaged if switched on electrically without any water in the tank.
qlmarine.com
 
#9 ·
SOLARE came with a new QL Water heater installed by the PO. I'm quite impressed with it as it provides almost instant hot water on shore power (15 minutes or less) and it keeps the water hot for well over a day.



qlmarine.com
Can the QL be heated by your engine? Meaning does it have a HX coil inside the tank that your engine cooling system runs through to heat the water when away from the dock?

None of the info on the web site seems to say it can be used in this fashion?
 
#11 ·
My old Atwood finally died an ungraceful death, and the replacement short list is a) Isotherm; b) SuperStor; c) Volvo/QL

I've read lots of raving comments on Isotherm, less on SuperStor, and none on Volvo/QL. Does anyone have any experience with this product? It looks great to me, but how does it do in the real world?

TIA, Zoran
 
#19 ·
My WH was tied to the engine (RWC) but failed to heat the water that way so I disconnected that circuit and only use the electric portion works fine on shore power. May be the fault of the RWC temps but I like the simpler system and didn't want the cooling water running around inside the boat.
Gotta check my brand after Maine's post.
 
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