Installing Water Heater w/ closed loop 8.1 engine?

[mckaras]

I'm looking for a bit of help on how to install a water heater with a closed loop cooling engine and what kind of water heater I'll need? I'm looking at two different Kuuma : KUUMA-11812 and KUUMA-11811 (The one I've replaced w/ water cooled engines)

What would I need to install it and make it work? My regal commodore originally had an instant water heater which is now discontinued and they no longer carry marine grade instant water heaters. I figured I may as well replace it with a traditional one since I have read only about complaints with the instant water heaters.

Thanks in advance.

 

[tpenfield]

You should be able to tap into the recirculating pump on the engine to heat the domestic water from the engine. Additionally, You'll be able to run from shore power.

You will need fittings and hoses to tap into the recirculating pump. Also a good idea to put in a couple of shut-off valves

 

[alldodge]

Manual 30

 

[mckaras]

You should be able to tap into the recirculating pump on the engine to heat the domestic water from the engine. Additionally, You'll be able to run from shore power.

You will need fittings and hoses to tap into the recirculating pump. Also a good idea to put in a couple of shut-off valves

Good deal, thank you. I'm assuming I would need this one : Kuuma 11811 ?

 

[alldodge]

They all work the same and the motor will heat any and all of them. The issue just comes down to what size your good with

 

[mckaras]

They all work the same and the motor will heat any and all of them. The issue just comes down to what size your good with

The other Kuuma I included the part number on only has a cold and hot, versus the other one has a supply/return.

 

[alldodge]

In a house
Cold comes in and Tees so cold travels on to all cold faucets and the other side goes into the hot water tank. It comes out of the hot water tank and goes to other side of all faucets

The one for $369 is a 120V only and does not allow for the motor coolant to heat up water. Your want the one which allows for shore power and motor hot water

 

[mckaras]

In a house
Cold comes in and Tees so cold travels on to all cold faucets and the other side goes into the hot water tank. It comes out of the hot water tank and goes to other side of all faucets

The one for $369 is a 120V only and does not allow for the motor coolant to heat up water. Your want the one which allows for shore power and motor hot water

Got it, thank you for the clarification alldodge!

 

[mckaras]

Manual 30

View attachment 415415

Hi Alldodge, do you by chance have a schematic for a set up I would need for a closed loop Volvo Penta 5.7?

 

[alldodge]

Hi Alldodge, do you by chance have a schematic for a set up I would need for a closed loop Volvo Penta 5.7?

There is no schematic and it's just 2 lines. One in and the other out.

 

[mckaras]

There is no schematic and it's just 2 lines. One in and the other out.

I see, the original engine was fresh water cooling that's why I was asking. It was just connected to the block drain ports. VP doesn't have the same ports as merc for the coolant lines to connect to the heater.

 

[alldodge]

I see, the original engine was fresh water cooling that's why I was asking. It was just connected to the block drain ports. VP doesn't have the same ports as merc for the coolant lines to connect to the heater.

I had a Merc that feed the water heater from the block drain port going in and the water pump housing on return. I don't have a VP 5.7 cooling system manual so I would guess which ever ports where used for open can also be used for closed unless the outlet went to the exhaust elbows

Which 5.7 do you have?
Edit: you said 8.1 and looking at water pump it may have the same port

 

[tpenfield]

You will probably have to figure out the flow of cooling water and take water to the water heater from a fairly hot side (under pressure), and give back to a colder side (under suction). The recirculating pump is good for this, so I would be looking there first.

 

[alldodge]

Here is someone who did it

Here is the thread
https://www.marineengine.com/boat-f...e-to-install-heater-water-lines.407602/page-2

 

[mckaras]

Here is someone who did it

Here is the thread
https://www.marineengine.com/boat-f...e-to-install-heater-water-lines.407602/page-2

Thank you once again Alldodge! Saved me a lot of time and gave me some useful insight for future projects!

 

[mckaras]

I had a Merc that feed the water heater from the block drain port going in and the water pump housing on return. I don't have a VP 5.7 cooling system manual so I would guess which ever ports where used for open can also be used for closed unless the outlet went to the exhaust elbows

Which 5.7 do you have?
Edit: you said 8.1 and looking at water pump it may have the same port

The volvo penta closed loop I'm working on is a 5.7 OSXI, fairly certain that's what it is. The other project I have is a merc 8.1 closed loop cooling system and the boat originally had a electric water heater.