On Tue, 23 Mar 2004 06:41:08 +0000, Calif Bill wrote:


"Lloyd Sumpter" wrote in message

Well, if the flow stops, the engine would most certainly overheat! Where
do you
think the heat for the heater comes from?? In a FW system, the "engine
coolant"
(which is also used for the heater) cools the engine, and the raw water
cools
the engine coolant (replacing a radiator in a car).


Works fine. Just like your car. Block off the heater hoses and the engine
still stays cool. Parallel circuits. My forward console Jetcraft runs the
water not above the engine, but does run it about 15' each way to the heater
core.
Bill

OK, now I'm really intriqued! I'm about to add HW heating to Far Cove, and I'm
concerned that the hose I'm interrupting is 1" and the hose I'm using is 5/8"
(Westerbeke reps say it's ok...) Also, in my old engine, I kept losing coolant
(and overheating!) because of a leak in the HW system hose.

Exactly how do these "parallel" systems work? Is there a bypass that shunts some
of the coolant around the HW circuit? If so, how does ANY water go through the
HW circuit? Is there some sort of valve?

Lloyd Sumpter
"Far Cove" Catalina 36

On Tue, 23 Mar 2004 07:13:02 -0800, "Lloyd Sumpter"
wrote:
Is there a bypass that shunts some
of the coolant around the HW circuit? If so, how does ANY water go through the
HW circuit? Is there some sort of valve?
========================================

Yes, the HW heater is on a parallel loop. In a car it's flow is
usually regulated by a thermostat as I understand it. The thermostat
opens and closes depending on temperature setting. Most, but not
all, of the coolant flow will take the path of least resistance, just
like a parallel electrical circuit.

"Wayne.B" wrote in message
...
On Tue, 23 Mar 2004 07:13:02 -0800, "Lloyd Sumpter"
wrote:
Is there a bypass that shunts some
of the coolant around the HW circuit? If so, how does ANY water go
through the
HW circuit? Is there some sort of valve?
========================================

Yes, the HW heater is on a parallel loop. In a car it's flow is
usually regulated by a thermostat as I understand it. The thermostat
opens and closes depending on temperature setting. Most, but not
all, of the coolant flow will take the path of least resistance, just
like a parallel electrical circuit.


Thermostat only makes the water warm. On a car and my boat, the waterpump
has an outlet for the heater. this is the return from the heater core. Out
of the intake manifold is an outlet for the ho****er feed to the heater.
Just changed the waterpump on wifes Blazer and this is the way it is.
Lloyd, look at your S10. Off the high pressure side of the waterpump is a
feed to the heater and on the suction side of the waterpump is a return
line.
Bill