Replacing my water heater

[Pete7]

Ok, we are getting there now, but you did confuse many of us early on.

Still we understand now what you're trying to achieve.

Pete

[RodrigoDC]

Originally Posted by Pete7

Ok, we are getting there now, but you did confuse many of us early on.

Still we understand now what you're trying to achieve.

Pete

I apologize. I did not intend to confuse anyone.

[Pete7]

Originally Posted by RodrigoDC

I apologize. I did not intend to confuse anyone.

That's fine don't worry The members were interested in helping you without wasting your hard earned money, hence the questions

[Stu Jackson]

Originally Posted by RodrigoDC

I apologize. I did not intend to confuse anyone.

Thx for the clarification. I misunderstood that the Raritan you had was a new one, not, as you've now explained, the old broken one.

[hjohnson]

The other thing that you need to decide is how you want to run the system. Engine connected systems, and marine ones in general, tend to heat the water to 90C which, directly, it’s unsafe for use. To resolve this, they include a thermostatic mixing valve to mix in cold water to the outflow and make it safe. It also has the side effect of increasing the amount of hot water available.

We have an isotemp tank on our boat. Eventually the heating element started to leak, but we were able to rebuild it.

They important thing to remember is that boat specific hot water tanks tend to be built for the high temperatures (Also with a higher pressure/temperature relief valve), significantly better insulation, and materials that won’t corrode away in a marine environment. Typical residential hot water tanks are made of mild steel, which won’t last long at all.

[JimsCAL]

How do intend to provide the electric power to the new heater? Shore power is fine, but what do you do when out cruising and spend the night on the hook or a mooring? With a Yanmar 2GM I doubt your boat is large enough for a genset.

[Simi 60]

Originally Posted by hjohnson

. Typical residential hot water tanks are made of mild steel, which won’t last long at all.

The one we just replaced was installed in 2004
Looked like new when we took it out

Only reason for replacement was 140 litres sucks too much battery power to heat, especially in winter with low solar production.
New 25 litre system is proving itself far more suitable for 2 people
Only took us six years to get around to it

[Rumrace]

I can’t recall a boat with hot water I’ve owned which didn’t have both.
When I have not had a generator was morning coffee with and the port engine running to heat the shower water.
Some folks run in the evening to wash dishes. I found this heated the aft cabins on most boats.
On a power boat your provided massive amounts of hot water in the electric hot water tank with out any battery sacrifice. Sailboats not so much just a short run coming into port or anchor.
I would not take it out and repair as necessary

[Stu Jackson]

Our "group" experience since 1986 is that the Seaward heaters installed in our boats have lasted between 10 and 16 years, usually 12 was pushing it. Kuuma is less expensive and doesn't last as long. Raritan is top of the line and does last longer. No experience with Isotemp.

[Celestialsailor]

To address the cost question...I was going to use the Bosch 7gl. electric only hot water heater for $250 and like yourself was based on cost. Then I found the Kuuma 6gl. electric and engine heater for $325. It was a no brainer. Been using it for a few weeks now...so far so good. I heated it up at 10am. to it's max temperature and still had relatively hot water at 4pm.

To answer the question of the two water ports (Input and return). I have always seen a loop here. I would suggest contacting the engine manufacturer or a facebook site for that engine and ask there.

[RodrigoDC]

Originally Posted by JimsCAL

How do intend to provide the electric power to the new heater? Shore power is fine, but what do you do when out cruising and spend the night on the hook or a mooring? With a Yanmar 2GM I doubt your boat is large enough for a genset.

No Genset on my boat, just hot water while using shore power and a few hours after that.


I do not live aboard, and typically do not use the boat much in the winter. Hot water is used principally in the early spring and late fall, mostly to wash dishes, so little consumption.


The price difference, even with the cheap marine WHs for me was huge. I noted a few WHs on eBay before for around $330 (https://www.ebay.com/itm/23312536608...Bk9SR7y76eL6YA), but these models do not fit on my 30 foot boat, only the cylindrical types such as the Raritan, which again, costs too much (about $1,000) for the use I provide.


I purchased a new 4 gallon Bosch electric WH for $60. Now, you don't have to be an accountant to figure this one out: little hot water use, cheap alternative, inspect the expensive one in the meantime. It's a no brainer for me.


Now that I know I can loop the input and return using one of the hoses currently connecting my Raritan WH, I'll go ahead and replace my leaky, expensive, seldomly used WH for a perfectly reasonably priced WH while I figure out what's wrong with the old one.


Thank you all for your contributions and suggestions.

[sailormed]

Originally Posted by Celestialsailor

………To answer the question of the two water ports (Input and return). I have always seen a loop here. I would suggest contacting the engine manufacturer or a facebook site for that engine and ask there.

These engine blocks are used worldwide in many use cases. Agriculture, mining, generators, RV, etc. Only on boats and RV’s is it important to have the option of a secondary engine coolant loop. It is an option, so not installing this option is in no case damaging the running of the engine.

[capn_billl]

Originally Posted by RodrigoDC

Stu, the reason I cannot simply use the Raritan HE, as stated above, is because the WH is leaking. At the very least, I will need to pull it off the boat and inspect it thoroughly to find out if the leak is at the tank level, meaning probably dead, or at the outlet level, which I may be able to fix.


I wish I could tell you that these projects will take me a day and that's it. Instead, this usually means that the boat will be without a WH for a while. So, why not replace it with a cheap electric WH even if it's only while I figure out whats wrong with the Raritan?


So I was not asking whether I should replace the WH, I was just asking what I need to do to the engine regarding both hoses. I can plug them, or I can simply use one of the hoses as a jumper hose, I believe is what I've been told.


If I can fix the Raritan and plug it back into the boat, great. Then I can use the electric water heater in my house, and the boat will enjoy hot water when using the engine. Happy ending!

I would jumper.

1. It's safe for any engine.

2. If you ever decide to buy an engine WH it's 100% reversible.

[rhubstuff]

If you ever plan to sell the boat, I think most people would expect an cooling water">engine cooling water heater, not just an electric one. What you are proposing will devalue your boat on the market, making it only sell-able to someone who wants to use the boat exactly as you do. Think of the water heater as an equity investment in the boat that will keep it marketable in the future.

[FlyingScot]

For those who are considering this option, or have done it, realize you are giving up 100-150 amp hours (@12v nominal) of basically free water heating in a 20-25L tank.

There is absolutely no way I would give that up to save a few bucks on the price of the water heater(s).

But hey, I like hot water!