Hot Water heater hoses
 

Speaking of hot water hoses and water heaters, has anyone heard of
engine overheat problems from running engine coolant (fresh water
system), a few feet (mayber 30 inches) above the engine block? I want
to add a heater at the helm, but my buddy, who did the same to his
similar boat, says the installer insisted on adding a circulation
pump. Not because there wouldn't be enough heat, but because "the
engine would overheat". This dosen't make sense to me since the
coolant flow for the heater is parallel to the engine cooling flow.
Even if the flow through the heater stops completely the engine should
still be properly cooled. Any experience or ideas?

Hot Water heater hoses
 

On Mon, 22 Mar 2004 15:33:21 +0000, Bob wrote:

Speaking of hot water hoses and water heaters, has anyone heard of engine
overheat problems from running engine coolant (fresh water system), a few feet
(mayber 30 inches) above the engine block? I want to add a heater at the helm,
but my buddy, who did the same to his similar boat, says the installer insisted
on adding a circulation pump. Not because there wouldn't be enough heat, but
because "the engine would overheat". This dosen't make sense to me since the
coolant flow for the heater is parallel to the engine cooling flow. Even if the
flow through the heater stops completely the engine should still be properly
cooled. Any experience or ideas?

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).

If you wanted a Totally Independant System, you could wrap some copper or SS
tubing round the exhaust, and use a circ pump to pump the water through that and
up through the heater. If THAT failed, your exhaust would just get a bit hotter.

OTOH, if the system is properly "closed", having it a few ft above the engine
shouldn't make any difference, because what goes up comes down: the extra energy
required to push the water UP is re-captured when the water goes DOWN.

You MIGHT have problems with airlocks in your heater, but that has nothing to do
with circulation. You might consider expansion tank, bleed valve, etc. I'd
suggest, in fact, that THIS would be the place to add/replace the coolant,
rather than at the engine.

Lloyd Sumpter
"Far Cove" Catalina 36

Hot Water heater hoses
 

"Lloyd Sumpter" wrote in message
...
On Mon, 22 Mar 2004 15:33:21 +0000, Bob wrote:

Speaking of hot water hoses and water heaters, has anyone heard of
engine
overheat problems from running engine coolant (fresh water system), a
few feet
(mayber 30 inches) above the engine block? I want to add a heater at the
helm,
but my buddy, who did the same to his similar boat, says the installer
insisted
on adding a circulation pump. Not because there wouldn't be enough
heat, but
because "the engine would overheat". This dosen't make sense to me since
the
coolant flow for the heater is parallel to the engine cooling flow. Even
if the
flow through the heater stops completely the engine should still be
properly
cooled. Any experience or ideas?

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).

If you wanted a Totally Independant System, you could wrap some copper or
SS
tubing round the exhaust, and use a circ pump to pump the water through
that and
up through the heater. If THAT failed, your exhaust would just get a bit
hotter.

OTOH, if the system is properly "closed", having it a few ft above the
engine
shouldn't make any difference, because what goes up comes down: the extra
energy
required to push the water UP is re-captured when the water goes DOWN.

You MIGHT have problems with airlocks in your heater, but that has nothing
to do
with circulation. You might consider expansion tank, bleed valve, etc. I'd
suggest, in fact, that THIS would be the place to add/replace the coolant,
rather than at the engine.

Lloyd Sumpter
"Far Cove" Catalina 36


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

Hot Water heater hoses
 

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

Hot Water heater hoses
 

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.

Hot Water heater hoses
 

"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