Connecting water heater to engine ? Advice needed !

[sfitr]

My Crownline 270 CR is equipped with a factory installed hot water heater which is a Seaward S650 model. The problem is that it only works on AC current when the boat is plugged to shore power. Most of my boating time is done on anchor so I have no AC current and so I have no hot water either. Is there a way to connect to water heater to the engine coolant lines ? I know some boats come like this from the factory.

I also can't find a way to disconnect the existing factory lines / pipes which feed the water heater from the fresh water tank. The plumbing is Whale Quick Connect .
.
The boat is powered by a 350Mag Mercruiser engine .

*** Edit :Seaward Water Heater Model is S650 not F650 sorry !

 

[H20Rat]

Re: Connecting water heater to engine ? Advice needed !

no... bad idea. At least with your setup. That is an electric water heater only! Your engine is cooled with raw water, so I wouldn't recommend running that into your waterheater if you want it to live.

So there are two alternatives... Option 1 is to get a water heater meant to run on engine heat, they have heat exchangers so the raw water never mixes with the fresh water. Keep in mind you won't get much hot water when at idle...

Option 2, which is what I run, is to add a plastic raw water storage tank with a wash down pump on it, for hot water shower use only! (have to be ok with spraying yourself with lakewater, but if you are just done with a wakeboarding run or a day on the beach...) The engine dumps its exhaust water into the tank, and an overflow on top of that sends it overboard via the normal route when full. The washdown pump draws from the bottom of the tank...

 

[agallant80]

Re: Connecting water heater to engine ? Advice needed !

The right way to go is to get a water heater with an exchange unit in it. If not you are risking flooding your boat if your make shift solution gives way.

You could buy a small generator for the swim platform. Honday eu2000i and the ryobi 2200 are good options.

 

[smokeonthewater]

Re: Connecting water heater to engine ? Advice needed !

Actually I'd say option 1 would be to look and see if your water heater already HAS a heat exchanger.... will be very obvious because there will be two unused ports on it.

 

[smokeonthewater]

Re: Connecting water heater to engine ? Advice needed !

Option 2, which is what I run, is to add a plastic raw water storage tank with a wash down pump on it, for hot water shower use only! (have to be ok with spraying yourself with lakewater, but if you are just done with a wakeboarding run or a day on the beach...) The engine dumps its exhaust water into the tank, and an overflow on top of that sends it overboard via the normal route when full. The washdown pump draws from the bottom of the tank...

Showering with water that has mixed with engine exhaust might not be very healthy.. jus sayin

 

[alldodge]

Re: Connecting water heater to engine ? Advice needed !

no... bad idea. At least with your setup. That is an electric water heater only! Your engine is cooled with raw water, so I wouldn't recommend running that into your waterheater if you want it to live.

So there are two alternatives... Option 1 is to get a water heater meant to run on engine heat, they have heat exchangers so the raw water never mixes with the fresh water. Keep in mind you won't get much hot water when at idle...

Option 2, which is what I run, is to add a plastic raw water storage tank with a wash down pump on it, for hot water shower use only! (have to be ok with spraying yourself with lakewater, but if you are just done with a wakeboarding run or a day on the beach...) The engine dumps its exhaust water into the tank, and an overflow on top of that sends it overboard via the normal route when full. The washdown pump draws from the bottom of the tank...

Use option one and get a hot water heater with a heat exchanger. I have one on my cruiser which the exchanger side runs from where the port side engine block drain was removed and a hose fitting is installed. Hose runs from the block to the exchanger, then from the other side runs to the engine water pump.

I don't like the whale quick fittings and have replaced them with brass compression fittings. No more leaks and when I want to disconnect there is no issue

 

[278 Vista]

Re: Connecting water heater to engine ? Advice needed !

Your model heater has the heat exchanger built in. Look for 2 plugs about half way up the unit that are directly above the inlet and outlets. You'll need to get the proper fittings to be able to install heater hoses to connect to your engine.

One tip once you're all fixed up; be careful. My water is much hotter when heated underway than on shorepower.

 

[agallant80]

Re: Connecting water heater to engine ? Advice needed !

I looked in to this before. If your heater has the fittings in it then you are good. Just need to buy the hose. There is also a temparture reguature you should get so you don't get scolding hot water from your block. Here is my thread

http://forums.iboats.com/boat-topic...ics/hot-water-heater-supply-block-595506.html

 

[The Great Escape II]

Re: Connecting water heater to engine ? Advice needed !

+1 that unit has a heat exchanger. Download the owners manual and it will tell you how to hook it up.

 

[wrench 3]

Re: Connecting water heater to engine ? Advice needed !

I had the same problem as you. (I bought a new water heater with a heat exchanger. Then when I pulled the old one out I found the heat exchanger ports on the back side, up against the hull) On my 454 I teed the feed in with the temp gauge sender. (The water is hotter at the top of the engine and the engine alarm switch is in the only other port at the top) I put the return into the water pump. I used the new heater (It plumbed easier with the ports on the front) and it had a thermostat built into the heat exchanger.
It gets up to temperature in about ten minutes of running and is still plenty hot after five hours at anchor.

 

[sfitr]

Re: Connecting water heater to engine ? Advice needed !

I had the same problem as you. (I bought a new water heater with a heat exchanger. Then when I pulled the old one out I found the heat exchanger ports on the back side, up against the hull) On my 454 I teed the feed in with the temp gauge sender. (The water is hotter at the top of the engine and the engine alarm switch is in the only other port at the top) I put the return into the water pump. I used the new heater (It plumbed easier with the ports on the front) and it had a thermostat built into the heat exchanger.
It gets up to temperature in about ten minutes of running and is still plenty hot after five hours at anchor.

Am going to try to remove it and see if it has heat exchanger ports on the back side..

 

[wrench 3]

Re: Connecting water heater to engine ? Advice needed !

I went looking for specs on your heater and came up with the owners manual for it at http://www.marlow-hunter.com/export/Vendor-Manuals/Seaward Water Heater Manual_S600.pdf and it's free. It shows the heat exchanger hookup at the back of the unit. The four ports on the front, as mentioned by 278 Vista, are used for the fresh water in and out, the pressure relief valve, and the drain plug/tap.
There was no mention of temperature control for the heat exchanger.

 

[Frank Acampora]

Re: Connecting water heater to engine ? Advice needed !

Uh, sfitr: It is a COLD water heater. Hot water does not need to be heated. LOL Sorry, it just needed to be said.

 

[H20Rat]

Re: Connecting water heater to engine ? Advice needed !

Showering with water that has mixed with engine exhaust might not be very healthy.. jus sayin

Depends on the engine/drive at least, normally you should be able to find a spot to T into that isn't mixed. On my sportjet (basically a merc outboard, there are two outbound water lines, one heads overboard via a small thru-hull, and the other heads into the 'lower unit' and then into the exhaust and overboard. I tapped the line that was normally headed directly overboard without engine exhaust, and fed that into a 3 gallon clear tank. I also have a washdown pump plumbed to that. (note, it is all ABOVE the waterline!) Worst case if the thing leaks, it just dumps into the bilge, and the engine suction bilge is more than enough to pump it out without even turning on an electric pump.

 

[sfitr]

Re: Connecting water heater to engine ? Advice needed !

Am running a Merc 350 MAG MPI Bravo 3 engine without fresh water cooling. I will try to uninstall the hot water heater tomorrow and see if it has heat exchanger ports on the back side since the back is mounted against the hull

 

[sfitr]

Re: Connecting water heater to engine ? Advice needed !

I removed my water heater today and guess what ? ! It has rear inputs for the heat exchanger ! I wonder why Crownline did not connect these from the factory.

Can someone enlighten me how am going to connect these to my Merc 350 Mag ? The engine does not have a closed cooling system.

 

[alldodge]

Re: Connecting water heater to engine ? Advice needed !

Edit: Use Mercs way

 

[Natesms]

Re: Connecting water heater to engine ? Advice needed !

You have to tap into the existing cooling lines/system that come from the motor. There will probably be a plug on the thermostat housing that you can use to get the hot water to the heater and then feed it back into the system somehow, I don't know for sure.

agallant80 posted a link when he went through the process, I'd start reading there. You might want to see if you can get some good pictures of the thermostat housing and lines and post them here, people will be better able to assist.

 

[smokeonthewater]

Re: Connecting water heater to engine ? Advice needed !

the thermostat is a point of restriction and creates a pressure variance.... inlet before t-stat and outlet after should get it done

Do not use ANY plastic fittings... brass fittings and automotive heater hose works well.... be very careful about how the hose lays. since this is a low pressure system it is more prone to kinking than in a car... consider 90 deg fittings where needed

Also understand that this will now be added to your winterizing process... The coils n hoses will need to be drained or filled w antifreeze so think about how you will do that and make it easy on yourself now.

 

[agallant80]

Re: Connecting water heater to engine ? Advice needed !

I removed my water heater today and guess what ? ! It has rear inputs for the heat exchanger ! I wonder why Crownline did not connect these from the factory.

Can someone enlighten me how am going to connect these to my Merc 350 Mag ? The engine does not have a closed cooling system.

If it makes you feel better Bayliner did not connect mine ether.

Check out my thread where I went through this DonS posted a nice diagram showing where to connect things up
http://forums.iboats.com/boat-topic...ics/hot-water-heater-supply-block-595506.html

Here is the diagram:
http://forums.iboats.com/attachment.php?attachmentid=185997&d=1363882567

Around the intake manifold near the t-stat housing should be a 1/2 inch plug that is where your hot water to the heater goes
On the water pump on the front of the block there should be another `1/2 incl plug that is where the return from the water heater goes

Good luck, I did this last year. West Marine had everything I needed.