Seaward S-600 water heater possible leak

[jonelli]

Something new I just noticed after a trip. Getting coolant loss into the bilge. 87 Catalina 30.
I’ve traced it back to under the water heater. I can see a small puddle and it’s not leaking very much but it is. I can’t see any signs of it leaking from the hoses or barbs so I’m thinking it’s the water heater.
Before I go ripping it out, anything special to look for?

 

[jonelli]

And if I’m looking at replacing, is there any other option of a new same one for $500?

 

[jviss]

If it's not leaking at the hoses or barbs, and it's the heat exchanger coil, you'd be getting coolant into the fresh water, not the bilge, I think. I would look more carefully at the hoses and barbs, maybe just re-do them and see what happens. Of course, I could be wrong, but that's my intuition.

 

[jviss]

In addition, you can test these before removing them. Once disconnected from the coolant and water lines (I know, easier said that done), you can pressurize both sides and see if they hold pressure. You would have to make a rig for this with a pressure gauge, but you can use air to pressurize it, and a bicycle pump to do that. It would be nice to know before you go ripping the heater out!

 

[jonelli]

Good idea. I can probably put that together.
Although the coolant is coming from somewhere and it ain’t the hoses. So I’m pretty sure it’s gonna be the heater.
Can you take one of these to a radiator shop?

 

[jviss]

Can you take one of these to a radiator shop?

I didn't think there were any radiator shops left! But, no, I don't think so. And after the effort of swapping out a heater, it's worth it to just put in a new one.

 

[JoeWhite]

I bought that water heater for $320.00 . My signs of leaking was similar to yours. After I replaced it with much unmentionable words I realized it was the coolant hose that was leaking which I also replaced. If it helps you how to replace visit
Sail La Vie | 1999 Catalina 36 MK II. See the album.

 

[Stu Jackson]

jonelli, how old is the heater? Our 25++ years with C34s indicate those Seawards last 12 to 16 years. My 1986 heater was replaced by the PO in 1998 and I replaced that one in 2013.

 

[jonelli]

jonelli, how old is the heater? Our 25++ years with C34s indicate those Seawards last 12 to 16 years. My 1986 heater was replaced by the PO in 1998 and I replaced that one in 2013.

No idea. It came with the boat which I’ve had for 9 years

 

[jonelli]

I bought that water heater for $320.00 . My signs of leaking was similar to yours. After I replaced it with much unmentionable words I realized it was the coolant hose that was leaking which I also replaced. If it helps you how to replace visit
Sail La Vie | 1999 Catalina 36 MK II. See the album.

Well, they’re $500 now.

 

[jssailem]

There are several designs. Critical, in my mind is adequate insulation. You want the hot water to still be ready the next day after driving your motor and heating the water.
Here is one.

Isotemp Basic Water Heaters | Fisheries Supply

Designed for use on boats, Isotherm's basic water heaters feature a durable stainless steel construction. Shop for marine-grade water heaters at Fisheries Supply.

www.fisheriessupply.com

 

[jonelli]

Anybody have an idea if these KUUMA water heaters fit in our same spot? Seems they are 5/8" taller than the Seaward ones:
$375 on Amazon. model # 11812

Camco Marine

Camco Marine

www.camcomarine.com

Dimensions: 13 ¾-inches (W) x 13 5/8-inches (H) x 19 ¾-inches (D) overall;

 

[sailcapt340]

They are that expensive now. Its been stated already, But you need to look more closely at the barbs in the back of the tank. Trust me, I know. The bell of the barbs in the back of that model (I have the same one) are just a little bit (ID Measurement) smaller than the 5/8” hose connected to them.
This leave a gap, that the clamps do not seal, when the hot coolant goes through and creates a drip. Again, I have the same model tank.

You said it’s coolant, not winterizing antifreeze (pink stuff). I only say this because I have had winterizing (pink stuff) left in the drain hose of that water heater. And over the course of the summer the hose dropped to the bottom of the tank and it leaked out. Leading me to believe I had a leaking tank, when I didn’t. Just thought I put that in here, for future reference.

That model also, at least in my case, had issues with the welded seams and those barbs. But you won’t know that until you get the outer cover off and look around. Not an easy job on my boat to do, given its location.
But that may be your only recourse.

 

[jonelli]

, But you need to look more closely at the barbs in the back of the tank. Trust me, I know. The bell of the barbs in the back of that model (I have the same one) are just a little bit (ID Measurement) smaller than the 5/8” hose connected to them.
This leave a gap, that the clamps do not seal, when the hot coolant goes through and creates a drip. Again, I have the same model tank.

I also called them (whale) and they said the same thing as you descriped. I will re-check it, but because of the age (more than 10 years), it's highly suspect.

 

[Stu Jackson]

Anybody have an idea if these KUUMA water heaters fit in our same spot? Seems they are 5/8" taller than the Seaward ones:

Aw, c'mon, you have the boat so who is in the best position to know if 5/8" will make a difference.

As has been previously reported, repeatedly, Kuuma is bottom of the line, looks like Seaward, costs less and doesn't last as long (6-8 years vs 12++). Isotemp is better much better with insulation that works and keeps the water hot long, much longer, it is a different shape so you have to check if it will fit, it comes with a temp valve, it costs more. Whether that longer lasting hot water is worth it depends on how you use your boat.

 

[sailcapt340]

Thats amazing in itself that they say the same thing. You would think for that small amount of metal stock in the manufacturing process they could address this. One good thing, though, they didn’t change the outside dimensions.
On my boat we‘re talking about the thickness of 3-4 sheets of paper clearance from the top of the tank to bottom of the settee cover.
Given the years your boat has had the Seaward 600, I count myself very fortunate that its still a working unit.
Check the input and exhaust hose ends when you take them off the barbs. They could be very dry and cracked from the heat and be the cause of a leak.

 

[jonelli]

Aw, c'mon, you have the bot so who is in the best position to know if 5/8" will make a difference.

As has been previously reported, repeatedly, Kuuma is bottom of the line, looks like Seaward, costs less and doesn't last as long (6-8 years vs 12++). Isotemp is better much better with insulation that works and keeps the water hot long, much longer, it is a different shape so you have to check if it will fit, it comes with a temp valve, it costs more. Whether that longer lasting hot water is worth it depends on how you use your boat.

Yah, sorry, I forgot I was posting in the all-sailors group!
I didn't know Kuuma is that much inferior. I've never paid attention to these water heaters, it's a new thing I'm learning! WM sells them both, Kuuma and Seaward, and they are very close in price,$550 vs $650. I just noticed that I can get the Kuuma for $350 online and was thinking of just being done with my problem for that much.
Although, now because of the feedback I got about checking it more, I'm thinking to first do all that, and see. Check the hoses again, maybe check with pressure too.

 

[Hello Below]

I didn't know Kuuma is that much inferior.

I am going to dip my toe in the water just to balance the reviews here. My, new on commissioning, Kuuma 5 gallon water heater is in its 12th year of fairly heavy use. It is dual heated by 110v AC or coolant via diesel or Espar hydronic furnace. I have added insulation where possible. Kuuma and Isotherm are for sure from different price points but how that equates to value I am unsure.

A quote from a very knowledgeable SBO contributor
“Your boat, your choice.”

 

[jonelli]

I am going to dip my toe in the water just to balance the reviews here. My, new on commissioning, Kuuma 5 gallon water heater is in its 12th year of fairly heavy use. It is dual heated by 110v AC or coolant via diesel or Espar hydronic furnace. I have added insulation where possible. Kuuma and Isotherm are for sure from different price points but how that equates to value I am unsure.

A quote from a very knowledgeable SBO contributor
“Your boat, your choice.”

Yep. Agree with that last quote. I think Stu has pretty good experience to offer which I’m inclined to listen to. But that said it’s really tempting especially since I’ve got some Amazon credit which would make that kuuma one really cheap for me. I’ll think about it

 

[dLj]

As has been previously reported, repeatedly, Kuuma is bottom of the line, looks like Seaward, costs less and doesn't last as long (6-8 years vs 12++). Isotemp is better much better with insulation that works and keeps the water hot long, much longer, it is a different shape so you have to check if it will fit, it comes with a temp valve, it costs more. Whether that longer lasting hot water is worth it depends on how you use your boat.

+1 on the Isotemp...

dj