Finding leak in fresh water system

[jimp1234]

I've started noticing a small amount of water (3-4 gal) in the bilge, and I've narrowed things down to a leak in my fresh water system. I've included a drawing of my water system. My first troubleshooting step was to fill the tanks, shut all the intake manifold valves, and then shut down the water pump. Then let the boat sit for a few days. Good news there wasn't all water in the bilge, and water gauges didn't drop so I'm assuming that water tanks are not leaking. Maybe?

Turned on the water pump yesterday, and opened one tank valve on the input manifold, but kept the valves on the distribution manifold turned off. Went on the boat today, water in the bilge and pump was running. However no evidence of water leaking from the pump, or the charcoal filter (see drawing) or anywhere else that I could see. Btw, I'm not living onboard, so I need some tricks to figure out where the leak is coming from while I'm off the boat.

Thanx

[SeaStory]

How often does the water pump come on?

Do you have an accumulator tank anywhere in the system?

Did you check around each manifold itself?

Have you tried a similar test with either of the other tanks? (ie, it could be something happening when the pump is pulling water through the system, but not when it is at rest)

Can you access the pipes/tubing between each item? ie, depending on age, you may be looking at a pinhole leak, and that is why it only leaks when the pump is left on/ the system is pressurized.

I would NOT leave the pump on when you are not onboard. If the leak gets worse, you could end up dry pumping and ruining the pump, or worse.

Good luck. Tracking down such leaks can be nerve wracking.

[peghall]

Easiest way to find a leak in a water tank: fill the tank and put a little red food coloring in the water. You'll see a red--or pink--depending on how much food coloring you used--stain on any leaks.


--Peggie

[jimp1234]

Thanks for the tip Peggie. I'll give that a try. Btw, I enjoyed reading your book. Maybe you'd care to offer an opinion on the following. My troubleshooting thus far indicates that the water leak only occurs when the water pump is turned on and the system is pressurized. Based on this it would seem to me that the leak is more likely coming from one of the lines (maybe a pinhole leak) rather than the tanks themselves? Or am I not thinking about this the right way?

Originally Posted by peghall

Easiest way to find a leak in a water tank: fill the tank and put a little red food coloring in the water. You'll see a red--or pink--depending on how much food coloring you used--stain on any leaks.


--Peggie

[jamhass]

Hot water heaters are frequent sources of unidentified pesky water leaks, as they are often hidden away in hard to see places. The cycling between hot and cold can lead to fittings loosening. Also, the pressure relief valves can be problematic as they age.

[JPA Cate]

check all your hose clamps on the pressurized lines. So far, we've not had any pinholes or cracks in water hoses, but lots of air leaks and failing clamps over the years.

Ann

[TheOffice]

What material are your hoses and fittings? The grey Qest fittings tend to crack.

Took me 2 years to find a bad pressure relief valve on the hot water heater.

[gonesail]

i have the polybutylene (replaced with pex) pipes and noticed the water pressure pump was cycling for no reason. i saw the water going into the bilge and found the cracked pipe. cut a 36" section out and replaced with pex pipe and fittings. all good.

[Bill O]

Originally Posted by jimp1234

I've started noticing a small amount of water (3-4 gal) in the bilge, and I've narrowed things down to a leak in my fresh water system. I've included a drawing of my water system. My first troubleshooting step was to fill the tanks, shut all the intake manifold valves, and then shut down the water pump. Then let the boat sit for a few days. Good news there wasn't all water in the bilge, and water gauges didn't drop so I'm assuming that water tanks are not leaking. Maybe?

Turned on the water pump yesterday, and opened one tank valve on the input manifold, but kept the valves on the distribution manifold turned off. Went on the boat today, water in the bilge and pump was running. However no evidence of water leaking from the pump, or the charcoal filter (see drawing) or anywhere else that I could see. Btw, I'm not living onboard, so I need some tricks to figure out where the leak is coming from while I'm off the boat.

Thanx

While maybe intuitive, you basically found from your testing the leak is after the tank manifold. Most likely it is after your pressure pump.
The dye trick is a good one, but my first attempt would be to use a mini water container (w/dye) from the pump inlet. While food coloring should be safe, more of a pain to get it out of a main tank so you don't continue to have colored water once you fix it.
After the filter, can you turn of the different sections of distribution manifolds to help isolate/narrow down the side that is leaking?

[sinnerman]

Hot water heater?

[JPK]

Another option is to use food-safe UV fluorescent dye. This will make spotting leaks in dark recesses easier by shining a UV light and spotting the glow of the dye. UV dyes are very handy for spotting all sorts of leaks (oil, coolant, water, etc.) Just make sure to select the appropriate dye for the application.

[Cheechako]

Holding a piece of toilet paper run it along any low spots on your hoses. When it gets wet, follow from there to the source.

Also, you can lay some TP flat on the inside of hull to find where the water is running from to the bilge.

[SV__Grace]

Originally Posted by peghall

Easiest way to find a leak in a water tank: fill the tank and put a little red food coloring in the water. You'll see a red--or pink--depending on how much food coloring you used--stain on any leaks.--Peggie

Similar strategy that I use is to draw lines under suspect fittings with a washable marker which will clearly show if water crossed over the line to track down the leak.

[MJH]

Originally Posted by jimp1234

I've started noticing a small amount of water (3-4 gal) in the bilge, and I've narrowed things down to a leak in my fresh water system. I've included a drawing of my water system. My first troubleshooting step was to fill the tanks, shut all the intake manifold valves, and then shut down the water pump. Then let the boat sit for a few days. Good news there wasn't all water in the bilge, and water gauges didn't drop so I'm assuming that water tanks are not leaking. Maybe?

Turned on the water pump yesterday, and opened one tank valve on the input manifold, but kept the valves on the distribution manifold turned off. Went on the boat today, water in the bilge and pump was running. However no evidence of water leaking from the pump, or the charcoal filter (see drawing) or anywhere else that I could see. Btw, I'm not living onboard, so I need some tricks to figure out where the leak is coming from while I'm off the boat. Thanx

I don't see the water heater in your diagram. That's where I have had leaks until I replaced the hose connection to it that cracked a few times due to age.

If it still leaks charge the water system and then check EVERY water hose connection.

~ ~ _/) ~ ~ MJH

[peghall]

My troubleshooting thus far indicates that the water leak only occurs when the water pump is turned on and the system is pressurized. Based on this it would seem to me that the leak is more likely coming from one of the lines (maybe a pinhole leak) rather than the tanks themselves?


I can't fault your logic. However, you should see pink water from a hole in the hose that water is being pushed through by the pump.


How old are the hoses? The average working life of any hose is only about 10 years 'cuz rubber and plastics dry out over time, becoming hard, brittle and prone to splitting and cracking. So if they're even close to 10 years, they might be telling you it's time to replace 'em.


--Peggie