Replace Hot Water Heater

Feb 26, 2004
22,759
Catalina 34 224 Maple Bay, BC, Canada
The Seaward manual, available on the web, indicate that the anodes are magnesium and are designed to deal with bad drinking water. They don't describe what that means.
 

KZW

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May 17, 2014
831
Catalina 310 #307 Bluewater Bay, FL
I found an installation manual on the web, but not an operations / maintenance manual.
 
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
I'm not sure an anode is needed for the hot water heater. It wouldn't hurt, but if Seaward doesn't have a spot for one I might not worry about it, unless your water is real hard or salty.
 
Feb 26, 2004
22,759
Catalina 34 224 Maple Bay, BC, Canada
There isn't one. It's all of twenty or so pages. It's called Owners Manual.

I found an installation manual on the web, but not an operations / maintenance manual.
 
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
Seaward DOES have a spot for one. It simply, as mentioned before, replaces the drain valve.
RTFM, Rob (Slapping head)!!
So you can have a drain valve, or an anode, but not both? Seems wrong.
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
Uh, guys.... I'm sure if it needed one, they would have designed one into the heater. Yanmars 3YM20s don't have one either.
 
Dec 25, 2008
1,580
catalina 310 Elk River
Being ignorant, how often must the anode be replaced?
Probably largely depends on the usage when connected to shore power. Just heating from the engine should have no effect.
I suppose you could argue that adding Clorox may cause corrosion as well.
 
May 2, 2012
276
Catalina 310 Toronto, Ontario
Hi KZW. I check mine ever year before haul out. The corrosion varies where the Anodes are and what is actually effecting them. The Magnesium anodes work the best, especially the one on the propeller shaft. I'm trying to fined out if I can us a Magnesium or stick with the Zinc Anodes used in the Heat Exchanger and where do you fine one.

Cheers
2 OLD PIRATES
 
Jan 22, 2008
214
Catalina 310 #147 Oakville Yacht Squadron
For what its worth, my zinc anode in my HX grew... Broke off trying to get it out.
Fortunately I was taking the HX out anyway to repair the hose neck that I crushed trying to get an engine hose off it when I was yanking my transmission... I think it may have been picking up material from my dissolving Magnesium shaft anodes
I have checked with the supplier of anodes and they don't make and don't have plans to make a magnesium pencil anode in magnesium for HX
Peter
C310 #147
For Pete's Sake
OYS
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
For what its worth, my zinc anode in my HX grew... Broke off trying to get it out.
Fortunately I was taking the HX out anyway to repair the hose neck that I crushed trying to get an engine hose off it when I was yanking my transmission... I think it may have been picking up material from my dissolving Magnesium shaft anodes
I have checked with the supplier of anodes and they don't make and don't have plans to make a magnesium pencil anode in magnesium for HX
Peter
C310 #147
For Pete's Sake
OYS
are you in freshwater
 
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Sep 15, 2009
6,243
S2 9.2a Fairhope Al
Actually I think Al is recommended for salt and brackish water
actually zinc is a better choice in the overall for brackish and salt ..depending on if you are closer to the salt than the fresh end of the brackish
 
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
The anode for the hot water heater is probably not going to be the same material as the anode for the shaft/strut/prop/engine heat exchanger, unless you're in fresh water, (or you've got an anode in the engine heating loop of your water heater-unlikely). The hot water heater is fresh water, and should be magnesium. For salt water all the others should be zinc.
 
Dec 25, 2008
1,580
catalina 310 Elk River
Ok, new Seaward F1100 installed, good plywood under platform to screw into. The engine hoses were long enough (slack up by the engine) to install to the starboard side with tang inserted in the slot, but the fresh water lines needed extending.

This 10" shorter HWH now provides room for direct access to the auto pilot rudder transducer if needed.

The manual indicated that the anode is attached to the drain valve and to use Zinc only, no Magnesium.
 
May 2, 2012
276
Catalina 310 Toronto, Ontario
HI peter_ms:
Since I'm looking for more than one anode, could you direct me to your source. I also need an anode for may Heat Xchanger and Hot Water Heater. Doing a once over for all the Anodes on the boat. Not sure what the previous owner did so I'm covering may bases.
Cheers
2 OLD PIRATES
 
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
Ok, new Seaward F1100 installed, good plywood under platform to screw into. The engine hoses were long enough (slack up by the engine) to install to the starboard side with tang inserted in the slot, but the fresh water lines needed extending.

This 10" shorter HWH now provides room for direct access to the auto pilot rudder transducer if needed.

The manual indicated that the anode is attached to the drain valve and to use Zinc only, no Magnesium.
Are you sure about the zinc anode? Every Seaward water heater manual I've seen says to not use zinc, only magnesium.
 
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
HI peter_ms:
Since I'm looking for more than one anode, could you direct me to your source. I also need an anode for may Heat Xchanger and Hot Water Heater. Doing a once over for all the Anodes on the boat. Not sure what the previous owner did so I'm covering may bases.
Cheers
2 OLD PIRATES
The HWH magnesium anode is available from Catalina Direct, West Marine, and Defender, plus a bunch of other distirbutors I'm sure (assuming you've got a Seaward HWH). Amazingly CD has the best price. I'm guessing they also have anodes for the HX unit.
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
Back on posts 11 and 19, the original post was hijacked into this anode discussion. WOULD SOMEONE PLEASE START A NEW THREAD AND LETS GET BACK TO THE op of fitting in a water heater???