Help plumbing water heater-gctid810858

[Ssjustaddwater]

I would like to add the eng water heater system back to my boat. I own a 2002 2859 and the water heater works great with land power but would like to set it up for off gride days.

Do you guys have any photos showing how you ran the lines in an out of both the motor and heater?

Cheers, Shawn

[builderdude]

Supply the water heater from the intake manifold upstream of the t stat and return goes to the starboard side of the engines circulating pump.



Attached files

[Ssjustaddwater]

I can see the connection points but just wondering how folks might have run the lines?

I love the space around the motor and just would

Like to keep it open.

Also which inlet do you run the hot water into the heater? Rt of lt side as you look at it?

[builderdude]

The heat exchanger within the water heater won't care what direction it flows, it's simply transferring heat from one liquid to the other.

[ronbo404]

Hi Shawn

Just to clarify not all hot water heaters have a heat exchanger for heating from the engine. The heat exchanger would have four ports

1) cold in

2) hot out

3) engine hot water in (3 and 4 can be reversed, does not matter)

4) engine bot water out.

Ron

[2850Bounty]

"Ssjustaddwater" post=810858 wrote:
I would like to add the eng water heater system back to my boat. I own a 2002 2859 and the water heater works great with land power but would like to set it up for off gride days.

Do you guys have any photos showing how you ran the lines in an out of both the engine and heater?

I can see the connection points but just wondering how folks might have run the lines? I love the space around the engine and just would like to keep it open.

[color]blue wrote:
Most often the hoses will leave the engine and will drop down and over to the Water Heater area.

If you can find a few sections of an old garden hose, you could do a test layout to determine the best routing and the lengths.

I would go with at least 5/8" heater hose! [/color]

Also which inlet do you run the hot water into the heater? Rt of lt side as you look at it?

[color]blue wrote:
Do you mean engine coolant supply/return for the water heater, or for the cabin heater?

In either event, it does not matter for the loop style WH heat exchanger, nor for the cabin heater!

Here's an updated version of my earlier drawing. [/color]

[attachment]36880 wrote:
WH and Cabin Heater coolant supply 5 .jpg[/attachment]

[color]blue wrote:
Here's a raw water cooled Merc V-8.[/color]

[attachment]36881 wrote:
WH and Cabin Heater coolant supply 2 .jpg[/attachment]

Attached files

[Ssjustaddwater]

Thanks guys!

As always your help is much appreciated.

Just what I was looking for

[Ssjustaddwater]

FBI Build list:

18' of 5/8 hearter hose

(4) hose clamps

(1) 1/2npt x 5/8 hose barb ( lower connection spot on water pump)

(1) 3/8npt x 5/8 hose bard ( upper connection spot above water pump)

1" webbing to make hose hangers.

[706jim]

I used most of 30' of heater hose to plumb the heater in a 246. Don't cut yourself short!

[builderdude]

Saw that also Rick, he wrote above the pump so I assumed he was referring to the intake manifold. He's got an 02, might be an mpi manifold or......?idk

[Guest]

I am looking for how to plumb to a MPI system. Can anyone help with this. I wrote a full discription about what I have and am doing under "96 2855 water heater"

[2850Bounty]

"Cmbrsum" post=814541 wrote:
I am looking for how to plumb to a MPI system. Can anyone help with this. I wrote a full discription about what I have and am doing under "96 2855 water heater"

[color]blue wrote:
It may be best if you were to start a new thread for your specific questions.

However, since we're here......... these are the important aspects of plumbing your engine coolant system (whether an "open" system or a "closed" system) into a Water Heater's "Heat Exchanger"!

The water heater's Heat Exchanger is often nothing more than a loop of tubing that runs through the water heater's holding tank.

There is nothing fancy about the heat exchanger tube.

These heat exchanger tubes are typically bi-directional.

...... we need mild positive pressure to create the supply.

...... we need a means of mild negative pressure to create the return.

...... the engine's Circulating pump charges the cylinder block with coolant (coolant = either seawater or ethylene glycol).

...... the thermostat holds back coolant on an "As Required" or "As Needed" basis.

...... when we pull our "supply" from a location prior to the thermostat, we can take advantage of this mild positive pressure.

...... when we plumb our "return" into the suction side of the Circ Pump, we can take advantage of the mild negative pressure.

...... with the two pressure differentials (positive and negative), we achieve flow to/from the WH Heat Exchanger...... and end up with a balanced scenario.

...... if we cannot achieve this balance, the system would then require what's refered to as a "puppy pump"...... and you do not want to do that!

Do it correctly, and you will not have any issues![/color]