Hot water smell

[AndyK]

On my 2004 Hunter 33 I have a Force10 (Kuuma) model 405001 5 gallon water heater. Recently it has developed a bad sulfur smell. I know - time to replace the anode...or so I thought. It looks like this particular water heater does not have an anode (see link), or at least one that is servicable. I have tried running clean water through it for twenty or thirty minutes with no luck. Short of replacing (this apparently obsolete) water heater are there any other suggestions?

Andy

 

[Peggie Hall-HeadMistress]

Nope

Although galvanized aluminum water heaters cost a lot less than glass lined water heaters, they can actually cost a lot more in the long run because the only cure when the galvanizing starts to wear off the inside of the tank is a new water heater. How often anodes in glass lined tanks or the galvanizing on the tank in an aluminum tank water heater can vary greatly depending upon the mineral and other content in the water that goes into i...sometimes as little 5 years, sometimes 20+ years. If it were my boat, I'd rather spend the extra money for a water heater that MIGHT need a $25 anode every 5 years or so--or never--over 25 years or more than have to spend a couple hundred $$ for whole new water heate every 5-10 years.

 

[Ross]

Peggy, Aren't zinc and aluminum side by side on the

noble metals list? I never before heard of galvanizing aluminum. I guess I still learn something new occasionally. I always thought Glass lined steel was the gold standard for water heaters.

 

[Jim]

You need a fresh water treatment.

run out the old tank and put in new water with the treatment. Stuff is growing in the hot water tank.

 

[Peggie Hall-HeadMistress]

Ross and Jim....

Ross, I misspoke...I meant to say ANODIZED aluminum, not galvanized. I dunno if glass lined tanks are the "gold standard," but they are the standard for household water heaters and top quality marine water heaters. They cost more, but last decades. But most of the cheaper water heaters have anodized aluminum tanks 'cuz it's lot less expensive than glass...and that's what most production boat builders use for the same reason. Unfortunately the same minerals etc that "melt" replaceable anodes in water heaters also "melt" the anodizing on the tank walls and there's no practical way to re-anodize the inside of a tank.

Jim, if both the cold AND hot water are funky, recommissioning the tank will cure the problem...but if ONLY the hot water smells like rotten eggs, the cold water is fine, that's a sure indication of a failed anode/anodizing...no water "treatment" will cure it.

 

[AndyK]

Just the hot water

It is only the hot water that has the smell. The cold water is fine. I recommission my boat's water system every year and have never had a problem previously.

My problem (and other Hunter 33 owners) is it looks like I need to find a different hot water heater to replace this one. Even if I wanted to do a one for one swap out it looks like this five gallon model is not sold any longer. It is a pretty small space and I need to find a new one that will fit exactly.

I see the Raritan glass lined six gallon model as the most likely replacement...except that it is 16.5" tall where the Force10(Kuumar) was 13.6" and fit almost flush to the locker cover over it (no more room). Force10's currently available six gallon model is the same height, just wider. I may be forced back to the same type of heater by space constraints.

Thanks for all of the responses.

Andy

 

[Ross]

Andy, How is this water heater fired?

You can find very small water heaters in wholesale plumbing supply companies. The ones supplied to the boat builders are probably just a part of the product line of a large manufacturer.

 

[Scott B]

Ross

they're 120V electric on shore power only. There's also a loop through the engine and draws heat while motoring.

 

[Peggie Hall-HeadMistress]

A couple of problems with that idea, Ross

Domestic water heaters are not equipped to provide a heat exchanger option...they're 115v only. So no hot water away from the dock unless you have a generator or a very large inverter and enough battery power to use it. Nor are the electrical connections etc spark protected.

They aren't nearly as durable either...the average lifespan of a glass lined domestic water heater is less than 10 years.

There are a bunch of things--faucets, sinks, pvc plumbing fittings etc--that are just marketed to the marine market by mfrs who make the same things for use on land, but water heaters aren't one of 'em. Marine water heaters are made by the companies whose names are on 'em.

 

[Ross]

Peggy and Scott, I see the problem. I was thinking fuel fired

for water heating. peggy, do you suppose that the anodized coating fails because of small defects that allow the aluminum to corrode beneath anodized finish. I think the anodizing leave aluminum oxide on the surface.

 

[Maine Sail]

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!!!!

This is cheesy and very misleading! At a minimum you have steel, aluminum, stainless, brass and perhaps copper in your HX/engine/domestic water circuit. Aluminum is the LEAST noble of these metals..!!! Do not pay big bucks for these 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 he HX is made of "cupronickel" 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..



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 common. There ARE differences in water heaters. The Superstors & Isotemps are worth the money! The "square" tanks are not...

 

[Peggie Hall-HeadMistress]

You're right that glass lined domestic water heaters have short life span

I've never had a domestic water heater last longer than 7-8 years. Typically it's the thermostat--which costs almost as much to replace as new water heater--that goes. But Raritan's glass lined water heaters typically last 25 years or even longer. I've had one on two boats, both OEM equipment...the first was 11 years old and still in good shape when I sold the boat...the second was 23 years old when I sold the boat, also still in good shape. Neither had ever needed any repair. And my experience is not atypical. But even if they had, their thermostats, heating elements, pressure relief valves and anodes for 'em are easily replaced and not very expensive...and I don't think I've ever heard of a tank failure.

I don't have ANY incentive whatever to recommend 'em--or to recommend ANYthing made by ANYone, btw.

 

[Maine Sail]

Good info Peggy..

but that's why I said that in the form of a question as in;

"Glass lined tanks don't last well in the residential world so why would they last in the marine environment?"

I had a Raritan fail on my own boat. It was showing some serious signs of rust around the inlet and outlet tapings and the foam was greatly rusty colored. Never actually autopsied it to see where the leak was.


I think I'll still buy a Isotemp when the time comes as I simply don;t trust glass lined tanks. If you had any idea of the amount of RMA I used to fill out on the glass lined tanks we sold you'd be horrified.. Of course residential tanks run 24/7 365 and boats are usually only part time not even 25% of that amount of use. Even at a 25% use figure of a home heater, which on average last about 5-7 years, you could still get many more years out of a glass lined tank on a boat if you maintain the anodes.

The water heaters I'd really shy away from are the square ones with aluminum tank...