Anything special I need to know about replacing the six gallon hot water heater?

[Bob4203]

I have to replace the hot water heater in my 1988 Mark II Catalina 30 and ended up getting a great deal through Defender for the OEM Seaward direct replacement hot water heater (rear heat exchanger hose attachments). Replacement regarding electrical connections are straight forward and the logistics of getting the old out and the new one in, challenging. My concerns are replacing the bib fitting with an anode (vessel is in fresh water) and the procedure for filling the tank (do I rely on the fresh water pump) or any other actions I have to take to get it working.
I have zero, ziltch, nada......experience with this. Any advise is appreciated.

Thanks
Bob
Georgia

 

[Stu Jackson]

You fill the domestic drinking water side with the water pump. Make very sure the tank in the heater is full by KNOWING water is flowing out of all of your faucets before ever turning on the heater.

The coolant side is important, too, you'll need to BURP your engine to avoid overheating. Engine Overheating 101 - How to Burp Your Engine (Reply #6) http://c34.org/bbs/index.php/topic,4518.msg26462.html#msg26462

 

[Stu Jackson]

My concerns are replacing the bib fitting with an anode (vessel is in fresh water)

The Seaward Manual says this about anodes:

ANODES
In a small number of instances tap water may have sufficient concentrations of dissolved salts to cause corrosion of the heater tank. Anode rods preserve the life of a water heater by corroding themselves so the water heater doesn't. These anode rods are easy to install! Simply replace the drain plug with this product to protect the water heater tank.

It has nothing to do with the water you are floating in.

You may not need it.

This 20 page Seaward manual I found online and copied it to my boat files. It seems to be much more comprehensive than the one I got with my new new heater in 2013.

 

[Bob4203]

thanks....
Bob

 

[Capt jgw]

I recommend the anode, especially if you're replacing the old one because it rusted out. You probably don't know what the pH and ion content of your marinas water is, and if you travel you'll be using water from many sources. If you don't use the boat a lot, the water just sits there in the tank and that's not good either. You don't want to have to change the heater again.

 

[boatpoker]

Water heaters can be expected to have a significantly shortened life due to corrosion if no air space is provided underneath and no hoses are connected to pressure relief valve or drain to lead dripping water away from the unit. The fiberglass batting around the aluminum tank (inside your stainless steel case) will suck up water and corrode the aluminum. Mount it on non-absorbent cleats.

 

[Stu Jackson]

Good points from boatpoker. When I put a new one in in 2013, I painted the bottom and halfway up the sides with Rustoleum and put a hose on the PRV.

 

[paulj]

Fill the water heater after it is installed..........

 

[Bob4203]

Thanks all.
I sail in fresh water (Lake Lanier, GA), which is the potable supply source for the Greater City of Atlanta. Its an Army Corp impoundment (they damed the Chattahoochee River in 1958). The potable supply source at the dock is of course treated (chlorinated/fluoridated) from the City of Gainesville, GA. Despite this, I always add a capful of "chlorox" when filling up my water tanks. We are weekend sailors with no ports of call, no intracoastal waterway, no planned lengthy voyages and limited destinations. As hard as I try to imagine the marina across the lake where I get diesel once a year is a face off place, the Moon Pie's and RC Cola at the counter bring me back to reality! Delight all you seawater sailors! I agree on the anode for my new water heater. No big deal making the installation. I have the anode in the diesel heat exchanger as well with no evidence of electrolysis, so why not? My old tank did not rust out.

Oh, the joys of freshwater sailing..........

Bob
1988 Mark II

 

[Maine Sail]

The biggest challenge with this project, on a late model C-30, is getting the old one out and the new one in. The galley drawer assembly needs to be removed. All hoses & wires moved off the hull below the drawer opening then the water heater slides to port and out the drawer opening. The fit is KY tight.....

 

[patrickkidd]

Water heaters can be expected to have a significantly shortened life due to corrosion if no air space is provided underneath and no hoses are connected to pressure relief valve or drain to lead dripping water away from the unit. The fiberglass batting around the aluminum tank (inside your stainless steel case) will suck up water and corrode the aluminum. Mount it on non-absorbent cleats.

I just found that this happened to my original Catalina 30 water heater which leaks very slowly into the lazarette. I unscrewed the unit from the lazarette floor, removed the stainless outer panel, and could feel corrosion and soggy fiberglass insulation under the tank.

It does seem like an anode and simply raising the unit off the lazarette floor will keep water from sitting on the metals. But what do you suggest for "kleets"?

Also, is buying an OEM unit from catalinadirect.com or defender.com the best option, or is there an updated aftermarket unit that might serve better? My heat exchanger couplings are in the rear of the unit.

Thanks!

 

[Bob4203]

Do a general GOOGLE search for the Seaward six gallon water heater (remember to keep in mind the front or rear hose connections from the engine) and you will be rather surprised on the price ranges! Their are numerous marine supply warehouses offering excellent prices.

Bob

 

[Bob S]

(remember to keep in mind the front or rear hose connections from the engine)

Not many are aware of these hoses because they run behind the unit. You have to remove the galley draw assembly to see them. After time they harden and crack. It would be a good time to change them out. I did. If they fail you will loose your antifreeze!