2004 MS 400 with Yanmar 370 . Adding auxiliary cabin heater

[Kickback]

Trying to research Engine coolant port locations to install a cabin heater using the engine coolant. Our 2004 MS 400 does not have a domestic hot water heater that is heated by the engine coolant, just shore power or the Generator.
IF it did have this it would be easier to install I could just tee into the existing lines.. Does anyone know where this ports are on a 370 Yanmar? A picture of these would be helpful. and what size fitting is needed and if it is Metric or National pipe fitting thread.
Thank You All for the help
Jerry

 

[porman]

There should be two plugs in the coolant pump. Sorry can't help with the thread size.

 

[DavidM]

The attached pic shows the water heater hook up locations on the Yanmar 6LY. The fittings are an obscure British BSP spec. A 3/8" NPT nipple will just fit though. Make sure you catch at least three threads. It is also a good idea to install shut off valves.

If engine hot water is useful to you in addition to the cabin heater, you can hook them both in series, the hot water heater first.

When you first run the engine with the hot water/cabin heater hooked up, leave the coolant cap off to let it vent and add coolant as necessary. Run it for a few minutes and all of a sudden you will feel hot water in the hose. That means it is vented and you can put the cap back on.

FWIW it seems that trawler builders rarely hook up the hot water heater, whereas sailboat builders always do.

David

 

[Comodave]

The attached pic shows the water heater hook up locations on the Yanmar 6LY. The fittings are an obscure British BSP spec. A 3/8" NPT nipple will just fit though. Make sure you catch at least three threads. It is also a good idea to install shut off valves.

If engine hot water is useful to you in addition to the cabin heater, you can hook them both in series, the hot water heater first.

When you first run the engine with the hot water/cabin heater hooked up, leave the coolant cap off to let it vent and add coolant as necessary. Run it for a few minutes and all of a sudden you will feel hot water in the hose. That means it is vented and you can put the cap back on.

FWIW it seems that trawler builders rarely hook up the hot water heater, whereas sailboat builders always do.

David

Of course it would be an obscure British BSP fitting, why not???

 

[Kickback]

I did not find the port as your diagraph showed. I found one on front of engine , there is a access hole in the L shaped metal guard over belt pulleys. Did not see a second one.

 

[DavidM]

I did not find the port as your diagraph showed. I found one on front of engine , there is a access hole in the L shaped metal guard over belt pulleys. Did not see a second one.

Hmmmm! The diagram worked for my 2006 MS 34T which had a Yanmar 6LY 370 hp engine. Can’t help any further.

David

 

[porman]

I'll be at the boat tomorrow and take a picture. If I can remember!

 

[Kickback]

Thank You Gary !

 

[porman]

Sorry, couldn't get to the boat today, but I'll definitely be there Thursday.

 

[porman]

heater inlet and outlet

Here you go. Compare this with DavidM's picture. They are under the belt guard.

 

[Kickback]

Great.
Thank You.
Jerry