Expected Seaward 6 gallon HW heater life?

[Rich Stidger]

I have a standard 6 gallon unit that currently has an inoperative Pressure-Temperature-Relief valve. I am wondering if I should just consider replacing the entire unit instead of just the valve since my unit has seen 10 seasons of service.The PTR valve is very tight and I need a much bigger wrench to get it out. I don't know if I could cause any damage to the tank in the removal process.Anyway, I'd like to hear of the lifespans that others have experienced.TIA

 

[Rick D]

Ten Years Is A Life Span

Rich, in my 32, I replaced the water heater in six years. On my 40.5, I replaced it at six and again at nine. Ours probably gets more use since we use the boat year-round, but even so, you are on the edge. FWIW, I got my last one through Boaters World at a really good price. An FYI, the second one I ordered, I paid big bucks for stainless steel. Save your money and get the galvanized one. The only thing stainless was the cover. It's still the aluminum guts. Rick D.

 

[fox islander]

10 yrs (had to check with the PO)

...but it was in really bad shape...just got the new one from defender...getting the old one out was a pain...next weekend is putting the new one in. Good luck.

 

[Stan Galper]

20+ Years

My 6 gal Seaward is over 20 years old, is used year-round, and it still works fine. I don't plan on replacing it until it starts to leak.

 

[Jim]

I would guess you at that point

it depends on the condition of the housing.

 

[RichH]

Depends on if the HWH has a replaceable ....

magnesium anode. Without the replaceable anode, you can get short life no matter what the internals. You always know instantly when the magnesium anode 'goes': rotten egg smell from the water.

 

[Ross]

RichH where does the H2S come from?

Just wondering.

 

[RichH]

Probably from sulfate reducing bacteria

... in the tank sediment and boiler scale. The complete digestion of the anode radically changes the electro chemistry of the tank, etc. and probably changes/enhances the bacteria's ability to produce the H2S, the sulfur being accumulated/concentrated by the bacteria. There are electrochemical ways to 'descale' piping, etc. ... and when done the H2S emission can be 'breath-taking'.

 

[Ross]

Thanks, I knew that there was a logical explanation.

I have pulled anodes from water heaters and they were covered with some sort of a jell.

 

[Rich Stidger]

Thanks, guys.....

I opted to replace it now. About a year ago I experienced an unexplained leak that did not recur, and now with the PTR valve failure, I think I may be wiser to replace before my sailing season starts.I could just replace the PTR valve, but a mid-season failure would cost me a weekend or more time to get a replacement and do the swap.I know that I usually have to replace my home HW tank long before 10 years, and I don't know if the same life cycle applies. I only have a six month sailing season and the HW unit is actually running only half of that time, but I think with the "unknown" factor I may be better off with a potentially premature replacement.

 

[RichH]

Other suggestion .....

Call the manufacturer get the hydro pressure test values (probably 1.5 times the 'rated' pressure). Take those values and the unit to a 'boiler', heat exchanger, etc. shop who does 'pressure testing'. If the unit passes that pressure, then you're probably *good to go* for a few more years. If not, you were going to spend the $ for a new one anyway. Dont do this type of pressure testing yourself if you absolutely dont know what you are doing .... severe caution implied.