4788 -- Recommendations for replacing water heater?-gctid823173

[riverguy42]

Hi all,

I'm getting ready to replace a leaking Seaward model S1800 water heater in our 2001 4788. I have removed the front cover to confirm that the leakage is from corrosion at the base of the tank.

I note that the new S1800's are listed as 20 gallon capacity, while mine is labeled as an 18 gallon model -- so the new S1800s are NOT the same as the old ones. This caused me to try to verify the dimensions of the newer tanks vs. the original s1800 and (of course) they are different. I measured the 'box' dimensions of my tank (excluding mounting feet and fittings) at 16"w x 16"d x 26.9"h. The opening that the new tank will have to fit into is exactly 17" x 21" -- but the new "S1800" specs say it measures 21w x 22d overall. I assume this includes the mounting feet, etc. but folks at Seaward were not able to tell me for certain, nor do they have measurements on the size of the actual metal enclosure box -- which is the critical thing to know.

My question...has anyone replaced an 18 Gallon S1800 in a 4788 with either the 'new' S1800 or the Kuuma 20 gallon? Any problems getting it into the hole?

Thanks in advance...

Riverguy

https://www.kuumaproducts.com/20-gallon

[smitty477]

"My question...has anyone replaced an 18 Gallon S1800 in a 4788 with either the 'new' S1800 or the Kuuma 20 gallon?"

Yes - we replaced with the Force/Kuuma 20 gallon water heater about 8 years back.

"Any problems getting it into the hole?"

Yes - its a tight fit requiring the clearing/removal of hoses, insulation, floor boards and some tight work but it will go in and function well once in place.

Just a couple of weeks ago one of the BOC members replaced his with the same 20 gallon Kuuma and had mentioned he cut off one mounting tab to make the unit fit in. He is a pilot so may not notice this thread until he gets time - hopefully he can give you an updated report on the newer units as our 20 gallon Kuuma was lightly different.

Also - back when we looked they had various configurations of that same 20 gallon unit - where the hoses come off, what the front dimension was vs the side etc.

So choose the exact model of the 20 gallon unit carefully to make sure the orientation is correct for your fit.

[Pacrimrat]

"smitty477" post=823174 wrote:
"My question...has anyone replaced an 18 Gallon S1800 in a 4788 with either the 'new' S1800 or the Kuuma 20 gallon?"

Yes - we replaced with the Force/Kuuma 20 gallon water heater about 8 years back.

"Any problems getting it into the hole?"

Yes - its a tight fit requiring the clearing/removal of hoses, insulation, floor boards and some tight work but it will go in and function well once in place.

Just a couple of weeks ago one of the BOC members replaced his with the same 20 gallon Kuuma and had mentioned he cut off one mounting tab to make the unit fit in. He is a pilot so may not notice this thread until he gets time - hopefully he can give you an updated report on the newer units as our 20 gallon Kuuma was lightly different.

Also - back when we looked they had various configurations of that same 20 gallon unit - where the hoses come off, what the front dimension was vs the side etc.

So choose the exact model of the 20 gallon unit carefully to make sure the orientation is correct for your fit.

I'm the guy,

I can give you a blow by blow if you decide to do it.

I ordered the 20 gal on a memory from a past post by Ron.

Once I got it to the boat I had reservations and contacted him about it.

Encouraged by his success I pursued it and finally got it in. Working alone.

It's a very close fit but not real bad if you prepare.

I'm happy with the results and the extra water. Our original was a 16 gal. It was 22 years old but still working.

I'm in route to Singapore so It might be a day before I can respond.

Chris

[capnken]

I replaced the 2 10 gallon Atwood tanks with a single 20 gallon Torrid stainless steel tank... heats faster and stays hot longer and uses the same footprint as a single Atwood tank. I then used the old Atwood 120V line to power the boiler element in my Hurricane hydronic heater. Tight fit getting it thru access but it fit in my 45. sits just forward of where the most forward Atwood sat. I even was able to use all the plumbing from the original setup. good luck!

[Woodsea]

I replaced the original S1800 least year. Bought a new S1800 from the company that took over previous manuf. It was almost exactly the same. I used all the same plumbing and was even able to use the same screw holes for the mounting feet.

[higgins_jr]

I figure I'm up for a new hot water service sooner rather than later, so this thread is helpful. With Steve's observations above of the new Seaward S1800 being a direct replacement, (at 16" x 16" x 27") I started some research. All of the resellers (Defender, Fisheries Supply, Westmarine, GO2marine) have the S1800 dimensions at 20 1/4" x 20 1/4" x 27". The manufacturer (Whale) has no dimensions on their website.

But looking at the picture graphic, and assuming that is still correct, it looks with a ruler more like a rectangular front versus "squarish" which would be in keeping with Steve's observations i.e. being the same size as the prior model. So I believe somehow all the resellers have the right height dimension of 27", but the wrong height and width measures. Stranger things have certainly happened. But to confirm the dimensions, I've sent a note to the manufacturer and will post their response when I hear back.

Chris and Smitty are talking about Kuuma tanks and it makes sense they are different. Hopefully a swapout of the original S1800 will be a simple exercise, but nothing is simple on a boat eh ?

Cheers

[Woodsea]

I should also mention that I removed the 2x2 trim the hatch rests on around the hatch entrance to give myself a little extra wiggle room. My recollection was it would fit without removal but I was working by myself and removing took about 5 minutes. Reinstalling the trim took another 5 minutes.

[NoSpeed]

You should also read this thread: http://www.baylinerownersclub.org/in...r-tank-removal I replaced mine with a Raritan 20 Gal. w/Heat Exchanger model in mid-2016.

[cosmo777]

"Pacrimrat" post=823487 wrote:


I'm in route to Singapore so It might be a day before I can respond.

Thought wifi in the cockpit wasn't certified?!?!? Using SATCOM while you're on AP?

All in jest, of course..

[Pacrimrat]

"cosmo777" post=824004 wrote:

"Pacrimrat" post=823487 wrote:


I'm in route to Singapore so It might be a day before I can respond.

Thought wifi in the cockpit wasn't certified?!?!? Using SATCOM while you're on AP?

All in jest, of course..

To hell with the cockpit I was in a first class seat... LOL

[Pacrimrat]

John,

I pulled the hatch support too for extra room.

I also used lifting straps to pull the old unit out and lower the new in. (8 or 10 bucks a harbor freight.)

The Kuuma comes with fore and aft mounts, port and starboard mounts or all four.

Where I bought mine they only stocked the all four so you can just cut off what you don't need or can't fit.

The Torrid heater mentioned is a beautiful unit but its over 1200 bucks. the Kuuma is $450. The original lasted 22 years so I went with the cheaper one.

Lifting the old unit out would be best with two people, (I did it alone and busted a gut) it was galvanized and had 20+ years f sediment in it. The new Kuuma is aluminum and empty so much easier to handle.

I'll post a photo when I get back to the boat.

Chris

[riverguy42]

So, my new Kuuma 20-gallon water heater is installed, and I was able to get it into it's spot without disassembling anything major. In my case I only had to remove several of the clamps that support the hydraulic lines routed across the area underneath the deck and manuever them to provide the last quarter-inch of vertical clearance. It is a VERY tight fit and I would expect that even minor (normal) variations in construction of each 4788 might have required a more extensive disassembly, so your results might vary.

If I ever have to get it OUT of that spot, there is a good chance it would need to come out in pieces!

If I had it to do over again, I would probably have used the Seaward model because the vertical dimension is almost 2" less than the Kuuma. The problem I found with the Seaward replacement is that it seems that none of their dealers keep them in stock -- three weeks lead time was the best I could find (from Defender, FYI). Since I was under the gun to get this thing replaced, I took the risk of buying the Kuuma that was in stock at Defender and shipped the same day.

Some notes:

The Kuuma is all aluminum with a very thin outer skin and was extremely light weight. This made it easier to handle.

I had to bend one of the mounting tabs up to about 60 degrees to get it into the hole. Fortunately the mounting tabs are also aluminum and quite malleable so it was easy to bend the tab and then un-bend it once it was in the hole.

In my case (2001 4788), it was quite apparent that removing any of the framework around the hole to enlarge the opening would have been a BIG job. Comparing my experience to a number of others here, I believe Bayliner made some changes/improvements to the construction compared to earlier models, perhaps to make the deck support more robust.

Unlike the Seaward S1800 I was replacing, the outer case of the Kuuma is pop-riveted, so there is no option to disassemble the unit to get it in piece-wise.

Bottom line is that the biggest challenge is the vertical clearance and I think I was ultimately lucky that I was able to get it into the space. That said, I really like the Kuuma water heater. The first thing I noticed is that the water-pressure pump builds up pressure and shuts off cleanly after opening a faucet, whereas the inner tank of the Seaward unit was apparently flexing under pressure and thus took longer to re-pressurize. This might have been due to age but I think it is more likely that the inner tanks of the newer units are designed better or perhaps use a better aluminum alloy.

Pictures to follow...

[riverguy42]

Photos:


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