[C38] water heater plumbing

[david at dlrfilms.com]

> If you have raw water flowing out of the boat and your coolant is
> flowing the most probable cause is a bad coolant pump(belt driven) or a
> leak in the head gasket.
>

Our boat has the surge tank add-on.

The head gasket idea is troubling, because if I had to describe what's
happening, I'd say that it seems like air is getting sucked into the
system.

None the less, I'll go through the fill burp procedure later today, and if
that doesn't fix it, I'll tear apart the coolant pump and see if that
turns anything up.

Thanks!