Thursday, January 4, 2024

Replacing our Hot Water Tank

Replacing our Seaward Hot Water Tank

Our Hot Water Tank was leaking when we pulled Eximius out of the water at Playboy Marine in Fort Lauderdale. Was it the piping or the Tank?

I Could see water dripping from the front bottom edge of the tank ( The face where the heating element electrical is located.) But it could be from almost anywhere, so time to pull the tank.

I removed the access door and frame on the port ( inboard ) side of the galley in order to maximize the space for tank removal.
The tank has 4 pipes connected, two to the front for the Hot & Cold water and two at the back for the Supply and Return of the coolant from the engine coolant pump. I had to disconnect the mid line pipe connections of the coolant pipes in order to drain some coolant into a bucket. Then I could disconnect the Coolant pipes from the back of the tank, it's virtually impossible to capture that coolant so I let it go into the bilge and pumped it out with a hand pump into an empty bottle.

Disconnecting the Hot & Cold pipes was easy but disconnecting the electrical supply not so. I had to cut one of the wires as I could not reach down to the terminal near the bottom of front of the tank.

The Tank is held in place with 4 screws into a wooden base beneath it, easy.  I had to unscrew the water pump from it's mounting in order to be able to slide the tank out. I say 'Slide' but in reality it took ten minutes to manipulate the tank into a position that it would come out of the galley structure.

I brought the tank home plus the bottles of the coolant/water mix that I pumped out of the bilge before leaving the boat at the dock.

Seaward S-700 Hot Water Heater

After dinner, with the tank at home, I removed the Stainless Steel outer housing. All of the fiberglass insulation between the housing and the tank was sopping wet. It took about 30 minutes to get the housing off then another 10 cleaning up the outside of the tank. Now the bad news! It looks like the tank has corroded near the central weld that joins the two ends of the tank. 

Of note, I found that the previous owner of the boat had the tank repaired at some point, his name and phone number were written on the tank.  Not sure when it was repaired but I decided to bite the bullet and replace the tank.

Looking online I found the identical tank ranging from $577 + tax+ shipping from several vendors, some had free shipping but slightly higher prices.

Kuma 6Gallon Hot Water Heater

I also found another brand for $414 inc Shipping & Taxes. It looks almost identical but with a couple of key differences.
The housing is Aluminum not Stainless steel, the Position of the Cold water inlet is several inches from that on the Seaward, but other than that, looks the same unit Size and all.

The new tank 'Kuma' arrives on Wednesday 12/272023. And we are heading out on the boat on 12/29/2023 for the new year's eve cruise.

So now the question is: Do I leave the tank out till after the new year and just bypass the coolant pipes and the Cold-Hot pipes so that we can run the engine and have water pressure for the weekend trip - - or Do I install the new tank as soon as it arrives - AND - what if it doesn't arrive.

Here's my plan. I'll cut the old Cold - Hot pipes out and replace them with longer pipes and then put elbows on both of them and a bypass pipe ( PEX ) between them - That way we can have water pressue and I'll remove the rubber hoses from the ends of the coolant supply and return and then put a bypass hose between them.  So if the new tank does not arrive, then I can simply fill the coolant tank on the engine, run it to burp any air out of the system and we can be on our way. If the new tank arrives on Wednesday, then I just need to remove the pass hoses and cut the cold/hot pipes to the correct length in order to connect them to the tank, then remove the coolant bypass hose, connect the pipes to the coolant supply and return to the tank, and then top up the engine coolant tank and burp the engine and we're ready to go.

It's a plan.  I'll go down on Tuesday and install the bypasses.

Meanwhile, what do I do with the old leaky tank and that nice Stainless Steel Housing????

I'll post an update in the New Year.