I woke up last night to the sound of the fresh water. I'd left the
switch on and it started in the middle of the night. The pump was
running dry and the water tank was empty. There isn't a
corresponding amount of water in the bilge and I couldn't find any
sign of a leak so I'm trying to figure out where the water went.

The pump has always cycled about every 10 minutes so I've been
thinking there must be a small leak somewhere but I never could find
it. We have the standard minimalist set up with a Jabsco PAR pump and
pressure switch and no accumulator or tank.

We have an Atlantic Marine hot water heater with the engine cooling
water running through it. One possibility is that the heating coil in
the tank corroded through and the water is leaking into the engine
cooling system and down the exhaust. The big concern here would be
filling up the muffler and then having water back up into the cylinder
with the open exhaust valve.

Has anyone heard of these heating coils developing leaks? Ours was a
fresh water boat until last season so it doesn't seem likely but it's
the only place I can think of the water going.

I'll turn the engine by hand or check for a high water level in the
muffler before starting the engine but I'd like to know if there is a
precedent for a leak in the heater coil

--

Roger Long

I don't know about water tank leaks, but I did once have a leak in the
exit hose which was plastic instead of the appropriate metal leader.
A few observations:

The pump shouldn't cycle at all. Normally, ours is tight and never
cycles, and the accumulator will even hold a bit of pressure after the
pump has been off for a week. (I'm actually headed to the boat this
morning to track down a leak suspected in the shower faucet.)

An accumulator is a very nice addition and can be added anywhere in
the system.

You should have a few shutoff valves in the system. In particular,
before the heater/hot water system is handy. Also, cockpit showers
are a weak point and should be isolated.



Roger Long wrote:
I woke up last night to the sound of the fresh water. I'd left the
switch on and it started in the middle of the night. The pump was
running dry and the water tank was empty. There isn't a
corresponding amount of water in the bilge and I couldn't find any
sign of a leak so I'm trying to figure out where the water went.

The pump has always cycled about every 10 minutes so I've been
thinking there must be a small leak somewhere but I never could find
it. We have the standard minimalist set up with a Jabsco PAR pump and
pressure switch and no accumulator or tank.

We have an Atlantic Marine hot water heater with the engine cooling
water running through it. One possibility is that the heating coil in
the tank corroded through and the water is leaking into the engine
cooling system and down the exhaust. The big concern here would be
filling up the muffler and then having water back up into the cylinder
with the open exhaust valve.

Has anyone heard of these heating coils developing leaks? Ours was a
fresh water boat until last season so it doesn't seem likely but it's
the only place I can think of the water going.

I'll turn the engine by hand or check for a high water level in the
muffler before starting the engine but I'd like to know if there is a
precedent for a leak in the heater coil

Jeff wrote in news:S7adnfFbO5U-
:

The pump shouldn't cycle at all. Normally, ours is tight and never
cycles, and the accumulator will even hold a bit of pressure after the
pump has been off for a week. (I'm actually headed to the boat this
morning to track down a leak suspected in the shower faucet.)



Yeah, but Roger has no accumulator to provide pressure to the system.
His is always hydrolocked making the pump cycle something awful unless
the faucets are wide open.

Roger you need an accumulator and will be amazed how much smoother the
water flow is and how little that pump cycles, saving the expensive pump
in the process. Make sure the T in the hose is on the BOTTOM of the
tank. The tank is supposed to have an air bubble. That's what makes it
work. I find them install upside down, even by boatyards who should know
better.

Your leak shouldn't be hard to find. Are you sure your bilge pump just
didn't empty the water out of the bilge, like it's supposed to do, when
the little water tank emptied?

If you suspect the heat exchanger of being the source of the leak, it's
easy to find, too. Just pull the hoses off the hot water tank from the
engine and let the tubing drain. Turn on the pump with the water tank
refilled and watch the fittings on the water tank to see if water comes
out. I doubt this is your problem. Is your engine cooling system all
raw water?? In a heat exchanger cooled engine, the hot water tank is
plumbed into the engine side full of antifreeze, not the seawater side
which doesn't get that hot. If you pumped the engine full of water from
a cracked hot water heater in a seawater cooled system, I'm sure it would
have flooded the engine exhaust by now.

More suspect is all that plastic tubing throughout the boat we call a
water system. It splits and cracks and stupids at the boatyard forget to
put hose clamps on it eventually leading to a hose coming loose to make a
mess for the bilge pump to clean up.

Just fill the water tank and turn the pump back on....should be easy to
spot if it emptied a full water tank before. Without an accumulator, and
no place to store pressure the accumulator provides, your water system
pump will cycle every few minutes to an hour....depending on the
hysteresis of the pressure switch and how much water leaks back through
the pump flapper valves, those little rubber disks they use for valves in
any water pump.

That cycling drives me crazy without an accumulator. How do you stand
it?

Roger Long wrote:
I woke up last night to the sound of the fresh water. I'd left the
switch on and it started in the middle of the night. The pump was
running dry and the water tank was empty. There isn't a
corresponding amount of water in the bilge and I couldn't find any
sign of a leak so I'm trying to figure out where the water went.

I don't think your water tank is empty...I think the diaphragm in your
water pump has failed.


The pump has always cycled about every 10 minutes so I've been
thinking there must be a small leak somewhere but I never could find
it.

As a diaphragm starts to fail, the pump will start to cycle for no
reason (there is a reason: a drop in pressure caused by the leaking
diaphragm)...at first just a brief "brrp" once or twice a day, then as
the tear in the diaphragm gets bigger, more and more frequently and
longer--and will take longer to prime when you first come aboard... till
finally the pump runs continuously without pumping any water.

I'll bet money that's what's happened. All you have to do to confirm it
is check the water level in your tank.

If your heat exchanger were leaking, you wouldn't have water in the
engine, you'd have coolant in your water.
--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://shop.sailboatowners.com/books...ku=90&cat=1304

"Peggie Hall" wrote

I'll bet money that's what's happened. All you have to do to confirm
it is check the water level in your tank.

The tank was bone dry.

If your heat exchanger were leaking, you wouldn't have water in the
engine, you'd have coolant in your water.

It's raw water cooled so all we would detect is the salt.
--

Roger Long

Roger Long wrote:
"Peggie Hall" wrote

I'll bet money that's what's happened. All you have to do to confirm
it is check the water level in your tank.

The tank was bone dry.

My money is still on the pump diaphragm. If you have a leak, the water
has to be somewhere. You wouldn't be the first person to think there was
more in the tank than you thought and ran it dry.

You said you woke up the sound of the fresh water...did you mean the
sound of water running somewhere? Or just the hammering of the water pump?

If your heat exchanger were leaking, you wouldn't have water in the
engine, you'd have coolant in your water.

It's raw water cooled so all we would detect is the salt.

Ok, SALT in your fresh water then.

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://shop.sailboatowners.com/books...ku=90&cat=1304

refill you tank and use either a pool dye (best) or food coloring... I
bet you find the bilge water to have changed color. Then you just need
to find the evaporated color stain and is should lead you to the leak.

I would refill it once more and try it without the dye first... that
will confirm if Peggy's theory is correct without staining your boat...



Peggie Hall wrote:

Roger Long wrote:

"Peggie Hall" wrote

I'll bet money that's what's happened. All you have to do to confirm
it is check the water level in your tank.


The tank was bone dry.


My money is still on the pump diaphragm. If you have a leak, the water
has to be somewhere. You wouldn't be the first person to think there was
more in the tank than you thought and ran it dry.

You said you woke up the sound of the fresh water...did you mean the
sound of water running somewhere? Or just the hammering of the water pump?

If your heat exchanger were leaking, you wouldn't have water in the
engine, you'd have coolant in your water.


It's raw water cooled so all we would detect is the salt.


Ok, SALT in your fresh water then.

I found the leak. Very small and didn't cause the problem on it's
own. It did however, cause the water tank to draw down faster than I
expected. It must have been just on the verge of sucking air when I
when I went to sleep. Now I know where that little wet trickle I
thought was collected condensation was coming from.

Next on my to do list, a way to check the fresh water tank level more
easily.

The pump is dry as a bone around the diaphragm, even after pumping
enough to fill the holding tank 3/4 full with fresh water to flush it.
The sink drain "T" into the head intake line works great although it
means a lot of head pumping.

The leak is in a metal to metal joint at the cold water inlet to the
heater. The drip runs down the hose to a low spot so it isn't easy to
spot.

--

Roger Long

Roger Long wrote:
I found the leak.

Shot my theory in the tail.

Very small and didn't cause the problem on it's
own.

Or did it...? Two problems, maybe?

The pump is dry as a bone around the diaphragm...

A failing/failed diaphragm wouldn't cause the pump to leak...it creates
an air leak in the pump that causes the pressure to drop, which turns on
the pump. As the tear in the diaphragm gets bigger, the pressure drops
more often and lower, causing the pump to cycle more frequently and
longer...till finally the pump can no longer prime.

even after pumping
enough to fill the holding tank 3/4 full with fresh water to flush it.

???...holding tank or water tank?

The sink drain "T" into the head intake line works great although it
means a lot of head pumping.

Most likely because the toilet is pulling air through the sink that's
preventing from priming. Put a plug in the sink when flushing with sea
water...when flushing with water from the the sink, the sink needs to be
at least half full. Just running water down the sink drain won't work
'cuz the toilet will pull more air than water.

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://shop.sailboatowners.com/books...ku=90&cat=1304

"Peggie Hall" wrote


A failing/failed diaphragm wouldn't cause the pump to leak...it
creates an air leak in the pump ....

Ah, light dawns! It's harder to make things vacuum tight than pressure
tight and much, much, harder than watertight. Developing porosity in
the rubber would do exactly what you describe.

The sink drain "T" into the head intake line works great although
it means a lot of head pumping.

Most likely because the toilet is pulling air through the sink
that's preventing from priming. Put a plug in the sink when flushing
with sea water...when flushing with water from the sink, the sink
needs to be at least half full. Just running water down the sink
drain won't work 'cuz the toilet will pull more air than water.

No, it works perfectly in normal head mode. There is a valve in the
line from the sink to the head intake line.

What I meant by lots of head pumping was filling a 13 gallon holding
tank by pumping the head. I really shouldn't have posted that point
because it only applies to our very funky marina where there is no
water hose bib within reach of the pump out station. I tried filling
the holding tank by pumping fresh water through the system to avoid
motoring back to the dock to fill with the hose through the deck pump
out the way any normal person would. Now that I've done that once,
motoring back and redocking doesn't seem like as much work as it did
before

--

Roger Long