Juan:

See page 49 of your Iveco 8141 shop manual, which can be found he

http://www.sabb.no/eng/viewfile.aspx?id=101

Note the diagram indicates (2) 'Heater Water Outlet, and (6) Heater
Water Inlet. I believe this is where you'll connect the 'calorifier'
or 'domestic water heater'

Then see:

http://www.raritaneng.com/pdf_files/...eaterv0502.pdf

for the installation instructions for one company's product, a unit
that allows 120 - 240 volt shore power hot water as well as engine
coolant hot water.

Mike Worrall
Los Angeles