Mercruiser inboard 4.3 - how to refit missing water heater (boiler)?

[Roger-B]

I just bought a motor yacht with Mercruiser inboard 4.3 and the water heater is missing. Can anyone help with fitting a replacement, please? I am a heating engineer (UK trained) but I'm not familiar with engine plumbing. So I need a guide on what goes where.

 

[Bondo]

Ayuh,...... Welcome Aboard,...... There should be a 1/2" pipe plug in the intake manifold, behind the t-stat housing, which is the hot water supply,.....
The water return should go to the 1/2" pipe plug in the circulating water pump housing,.....

 

[Grub54891]

And measure the space it sits in. Some are in pretty tight spots.

 

[alldodge]

Would help to know the serial number of the motor, and if its closed or open cool. This is one way

 

[Roger-B]

Thank you so much for your replies. The actual boat owner (my friend, Roger) is dyslexic and doesn't own a computer so I signed up and posted this question on his behalf. I will pass your replies to him. The boat is currently moored about 100km away (we are on Crete island, Mediterranean) and he will not be back on board until the weekend. So I will ask him to photograph the engine and get the serial number.

Thanks again for your prompt replies. What a fantastic community!

Martin