Topics

FRESH WATER SAFETY CUTOFF

Steven Bode - SV Intention 1994-SM#117
 

FRESH WATER SAFETY SHUTOFF SYSTEM REQUEST FOR COMMENTS

Amelians, I believe that there is a serious issue with the fresh water pump system on the Super Maramu and I would like your input. 

The problem: In the event of a failure of the pressurized freshwater system — a break anywhere in the water plumbing, the entire freshwater supply could be drained overboard resulting in (a) loss of critical freshwater, (b) overuse of the freshwater pump (killing it) and (c) over use of the main bilge pump (killing it, too). Don’t ask me how I know.

Situational description: The freshwater pump may be left on. This is often the case when people are onboard, for example overnight or sometimes when they are ashore (off the boat).

The pump will pressurize the water system and remain off as long as the system remains pressurized. The pump will activate automatically any time there is a drop in water pressure.

If there is a break in the pressurized water system — a fault, then the pump will activate and run continuously until it is switched off, draining the entire fresh water supply into the bilge where it will be pumped overboard by the main bilge pump. This is a costly occurrence or possibly a safety issue if fresh water can not be resupplied, for example if the boat is off shore and there is no water maker.

A Proposal: A safety mechanism is needed to prevent this. A simple solution would be a timer that is activated every time the pump is activated. When the timer expires the pump is automatically deactivated until the system is manually reset. By determining the average time the pump is running each time it is activated, the timer could be set to shut off the system whenever above average run time is encountered. For example, if the pump typically runs for an average of 60 seconds, then the timer could be set for five minutes. If the pump runs for five minutes, then the timer turns off the power to the water pump, functioning like a breaker. The pump must be reset manually like a breaker.

Resetting the breaker: Ideally, this timer circuit would reset automatically once water pressure is restored, but that is much more complicated as it would require the deactivated pump to be turned on again or some other system employed.

 

This is a request for comments from those of you out there who have either considered this issue or who would like to develop a solution. I propose that a timer circuit be introduced between the breaker and the pump to serve as a safety device. It would be unobtrusive as long as the water was not to remain open for more than the timer duration. I am not a circuit designer, but I have been researching homebuilt circuits that might work.

--
Steve Bode, Sailing Vessel Intention
Amel Super Maramu #117 (1994) 
Western Mediterranean
+1 415-710-6659 voice/text/whatsapp
 

Mohammad Shirloo
 

Hello Steve;

 

You make valid points. However, we feel that at some point, we must have standard operating procedures, that address issues like the one you mention. There are many systems on board that could create undesirable and sometime dangerous conditions, if we do not think them through and have operating procedures that address these conditions. In regards to the issue you correctly point out, we never leave the water pressure breaker on, while away from the boat, at night or while under way. This simple SOP addresses this concern for us.

 

It is my opinion that by trying to prevent all potential issues that may arise , without the need for standard operating procedures that prevent them, we will create a far more complex system, than our boats currently are, with sometimes unintended outcomes.

 

One of the main reasons we were drawn to the Amel concept, was the fact that thousands of the same design concepts had done what we intended to do and had been tested in real life conditions. We did not feel that Amel design were necessarily the best, but that they had been well tested and proven throughout decades of real life conditions.

 

Happy Sailing;

 

 

Mohammad and Aty

B&B Kokomo

AMEL 54 #099

 

From: main@AmelYachtOwners.groups.io <main@AmelYachtOwners.groups.io> On Behalf Of Steven Bode - SV Intention 1994-SM#117 via groups.io
Sent: Sunday, May 10, 2020 10:52 PM
To: main@AmelYachtOwners.groups.io
Subject: [AmelYachtOwners] FRESH WATER SAFETY CUTOFF

 

FRESH WATER SAFETY SHUTOFF SYSTEM REQUEST FOR COMMENTS

Amelians, I believe that there is a serious issue with the fresh water pump system on the Super Maramu and I would like your input. 

The problem: In the event of a failure of the pressurized freshwater system — a break anywhere in the water plumbing, the entire freshwater supply could be drained overboard resulting in (a) loss of critical freshwater, (b) overuse of the freshwater pump (killing it) and (c) over use of the main bilge pump (killing it, too). Don’t ask me how I know.

Situational description: The freshwater pump may be left on. This is often the case when people are onboard, for example overnight or sometimes when they are ashore (off the boat).

The pump will pressurize the water system and remain off as long as the system remains pressurized. The pump will activate automatically any time there is a drop in water pressure.

If there is a break in the pressurized water system — a fault, then the pump will activate and run continuously until it is switched off, draining the entire fresh water supply into the bilge where it will be pumped overboard by the main bilge pump. This is a costly occurrence or possibly a safety issue if fresh water can not be resupplied, for example if the boat is off shore and there is no water maker.

A Proposal: A safety mechanism is needed to prevent this. A simple solution would be a timer that is activated every time the pump is activated. When the timer expires the pump is automatically deactivated until the system is manually reset. By determining the average time the pump is running each time it is activated, the timer could be set to shut off the system whenever above average run time is encountered. For example, if the pump typically runs for an average of 60 seconds, then the timer could be set for five minutes. If the pump runs for five minutes, then the timer turns off the power to the water pump, functioning like a breaker. The pump must be reset manually like a breaker.

Resetting the breaker: Ideally, this timer circuit would reset automatically once water pressure is restored, but that is much more complicated as it would require the deactivated pump to be turned on again or some other system employed.

 

This is a request for comments from those of you out there who have either considered this issue or who would like to develop a solution. I propose that a timer circuit be introduced between the breaker and the pump to serve as a safety device. It would be unobtrusive as long as the water was not to remain open for more than the timer duration. I am not a circuit designer, but I have been researching homebuilt circuits that might work.

--

Steve Bode, Sailing Vessel Intention

Amel Super Maramu #117 (1994) 

Western Mediterranean

+1 415-710-6659 voice/text/whatsapp

 

Danny and Yvonne SIMMS
 

Hi Steve,

in the first month of our ownership of Ocean Pearl a pin hole developed in the hot water cylinder. We were ashore and when we got back the fresh water pump was merrily running pouring water into the bilge. Fortunately we were back on board very soon after the leak developed. You are quite right about the risk this presents, particularly if the bilge pump fails and 900 litres of water finishes up in the engine room. I would choose overboard any day. So we always turn the fresh water breaker off when we leave the boat. We also installed a very intrusive beeping alarm that functions when the bilge pump is operating. Could be considered irritating but we like knowing when the bilge pump is going. Keeps us informed. If there are shower hungry guests aboard who continually have long showers the bilge alarm notifies us to do a sneaky turn off of the water pump. grin.

Danny

SM 299

Ocean Pearl

On 11 May 2020 at 17:51 Steven Bode - SV Intention 1994-SM#117 <steve@...> wrote:

FRESH WATER SAFETY SHUTOFF SYSTEM REQUEST FOR COMMENTS

Amelians, I believe that there is a serious issue with the fresh water pump system on the Super Maramu and I would like your input. 

The problem: In the event of a failure of the pressurized freshwater system — a break anywhere in the water plumbing, the entire freshwater supply could be drained overboard resulting in (a) loss of critical freshwater, (b) overuse of the freshwater pump (killing it) and (c) over use of the main bilge pump (killing it, too). Don’t ask me how I know.

Situational description: The freshwater pump may be left on. This is often the case when people are onboard, for example overnight or sometimes when they are ashore (off the boat).

The pump will pressurize the water system and remain off as long as the system remains pressurized. The pump will activate automatically any time there is a drop in water pressure.

If there is a break in the pressurized water system — a fault, then the pump will activate and run continuously until it is switched off, draining the entire fresh water supply into the bilge where it will be pumped overboard by the main bilge pump. This is a costly occurrence or possibly a safety issue if fresh water can not be resupplied, for example if the boat is off shore and there is no water maker.

A Proposal: A safety mechanism is needed to prevent this. A simple solution would be a timer that is activated every time the pump is activated. When the timer expires the pump is automatically deactivated until the system is manually reset. By determining the average time the pump is running each time it is activated, the timer could be set to shut off the system whenever above average run time is encountered. For example, if the pump typically runs for an average of 60 seconds, then the timer could be set for five minutes. If the pump runs for five minutes, then the timer turns off the power to the water pump, functioning like a breaker. The pump must be reset manually like a breaker.

Resetting the breaker: Ideally, this timer circuit would reset automatically once water pressure is restored, but that is much more complicated as it would require the deactivated pump to be turned on again or some other system employed.

 

This is a request for comments from those of you out there who have either considered this issue or who would like to develop a solution. I propose that a timer circuit be introduced between the breaker and the pump to serve as a safety device. It would be unobtrusive as long as the water was not to remain open for more than the timer duration. I am not a circuit designer, but I have been researching homebuilt circuits that might work.

--
Steve Bode, Sailing Vessel Intention
Amel Super Maramu #117 (1994) 
Western Mediterranean
+1 415-710-6659 voice/text/whatsapp
 

Danny and Yvonne SIMMS
 

Hi Mohammed,

totally agree. I marvel and cringe at the complex electronic and electrical systems some people are adding. Not something for a boat intended for extended off shore sailing in remote third world locations.

Danny

SM 299 Ocean Pearl

On 11 May 2020 at 18:07 Mohammad Shirloo <mshirloo@...> wrote:

Hello Steve;

 

You make valid points. However, we feel that at some point, we must have standard operating procedures, that address issues like the one you mention. There are many systems on board that could create undesirable and sometime dangerous conditions, if we do not think them through and have operating procedures that address these conditions. In regards to the issue you correctly point out, we never leave the water pressure breaker on, while away from the boat, at night or while under way. This simple SOP addresses this concern for us.

 

It is my opinion that by trying to prevent all potential issues that may arise , without the need for standard operating procedures that prevent them, we will create a far more complex system, than our boats currently are, with sometimes unintended outcomes.

 

One of the main reasons we were drawn to the Amel concept, was the fact that thousands of the same design concepts had done what we intended to do and had been tested in real life conditions. We did not feel that Amel design were necessarily the best, but that they had been well tested and proven throughout decades of real life conditions.

 

Happy Sailing;

 

 

Mohammad and Aty

B&B Kokomo

AMEL 54 #099

 

From: main@AmelYachtOwners.groups.io <main@AmelYachtOwners.groups.io> On Behalf Of Steven Bode - SV Intention 1994-SM#117 via groups.io
Sent: Sunday, May 10, 2020 10:52 PM
To: main@AmelYachtOwners.groups.io
Subject: [AmelYachtOwners] FRESH WATER SAFETY CUTOFF

 

FRESH WATER SAFETY SHUTOFF SYSTEM REQUEST FOR COMMENTS

Amelians, I believe that there is a serious issue with the fresh water pump system on the Super Maramu and I would like your input. 

The problem: In the event of a failure of the pressurized freshwater system — a break anywhere in the water plumbing, the entire freshwater supply could be drained overboard resulting in (a) loss of critical freshwater, (b) overuse of the freshwater pump (killing it) and (c) over use of the main bilge pump (killing it, too). Don’t ask me how I know.

Situational description: The freshwater pump may be left on. This is often the case when people are onboard, for example overnight or sometimes when they are ashore (off the boat).

The pump will pressurize the water system and remain off as long as the system remains pressurized. The pump will activate automatically any time there is a drop in water pressure.

If there is a break in the pressurized water system — a fault, then the pump will activate and run continuously until it is switched off, draining the entire fresh water supply into the bilge where it will be pumped overboard by the main bilge pump. This is a costly occurrence or possibly a safety issue if fresh water can not be resupplied, for example if the boat is off shore and there is no water maker.

A Proposal: A safety mechanism is needed to prevent this. A simple solution would be a timer that is activated every time the pump is activated. When the timer expires the pump is automatically deactivated until the system is manually reset. By determining the average time the pump is running each time it is activated, the timer could be set to shut off the system whenever above average run time is encountered. For example, if the pump typically runs for an average of 60 seconds, then the timer could be set for five minutes. If the pump runs for five minutes, then the timer turns off the power to the water pump, functioning like a breaker. The pump must be reset manually like a breaker.

Resetting the breaker: Ideally, this timer circuit would reset automatically once water pressure is restored, but that is much more complicated as it would require the deactivated pump to be turned on again or some other system employed.

 

This is a request for comments from those of you out there who have either considered this issue or who would like to develop a solution. I propose that a timer circuit be introduced between the breaker and the pump to serve as a safety device. It would be unobtrusive as long as the water was not to remain open for more than the timer duration. I am not a circuit designer, but I have been researching homebuilt circuits that might work.

--

Steve Bode, Sailing Vessel Intention

Amel Super Maramu #117 (1994) 

Western Mediterranean

+1 415-710-6659 voice/text/whatsapp

 

 



 


 

Mohammad Shirloo
 

Hi again Steve;

 

I forgot to mention that we will be installing the Yacht Sentinel boat monitoring system that has many functions that it monitors such as Geofencing (Anchor drag), low battery, high water, motion sensor, shore power, temperature (battery compartment, engine room, etc.) and more. It is also setup for remote monitoring and notifications, while you are away from the boat, in case anything goes wrong so you can be informed and respond to any condition.

 

For example, many water intrusion alarms can be installed in areas where the water will first start accumulating, if there is a breach of fresh water lines or a breach to sea water. There are many issues that may lead to unwanted outcomes. In our opinion, monitoring and being alerted to these is the way to go so we do not interfere with the normal operation of boat systems.

 

Happy Sailing;

 

 

Mohammad and Aty

B&B Kokomo

AMEL 54 #099

 

From: main@AmelYachtOwners.groups.io <main@AmelYachtOwners.groups.io> On Behalf Of Danny and Yvonne SIMMS via groups.io
Sent: Sunday, May 10, 2020 11:20 PM
To: main@AmelYachtOwners.groups.io
Subject: Re: [AmelYachtOwners] FRESH WATER SAFETY CUTOFF

 

Hi Steve,

in the first month of our ownership of Ocean Pearl a pin hole developed in the hot water cylinder. We were ashore and when we got back the fresh water pump was merrily running pouring water into the bilge. Fortunately we were back on board very soon after the leak developed. You are quite right about the risk this presents, particularly if the bilge pump fails and 900 litres of water finishes up in the engine room. I would choose overboard any day. So we always turn the fresh water breaker off when we leave the boat. We also installed a very intrusive beeping alarm that functions when the bilge pump is operating. Could be considered irritating but we like knowing when the bilge pump is going. Keeps us informed. If there are shower hungry guests aboard who continually have long showers the bilge alarm notifies us to do a sneaky turn off of the water pump. grin.

Danny

SM 299

Ocean Pearl

On 11 May 2020 at 17:51 Steven Bode - SV Intention 1994-SM#117 <steve@...> wrote:


FRESH WATER SAFETY SHUTOFF SYSTEM REQUEST FOR COMMENTS

Amelians, I believe that there is a serious issue with the fresh water pump system on the Super Maramu and I would like your input. 

The problem: In the event of a failure of the pressurized freshwater system — a break anywhere in the water plumbing, the entire freshwater supply could be drained overboard resulting in (a) loss of critical freshwater, (b) overuse of the freshwater pump (killing it) and (c) over use of the main bilge pump (killing it, too). Don’t ask me how I know.

Situational description: The freshwater pump may be left on. This is often the case when people are onboard, for example overnight or sometimes when they are ashore (off the boat).

The pump will pressurize the water system and remain off as long as the system remains pressurized. The pump will activate automatically any time there is a drop in water pressure.

If there is a break in the pressurized water system — a fault, then the pump will activate and run continuously until it is switched off, draining the entire fresh water supply into the bilge where it will be pumped overboard by the main bilge pump. This is a costly occurrence or possibly a safety issue if fresh water can not be resupplied, for example if the boat is off shore and there is no water maker.

A Proposal: A safety mechanism is needed to prevent this. A simple solution would be a timer that is activated every time the pump is activated. When the timer expires the pump is automatically deactivated until the system is manually reset. By determining the average time the pump is running each time it is activated, the timer could be set to shut off the system whenever above average run time is encountered. For example, if the pump typically runs for an average of 60 seconds, then the timer could be set for five minutes. If the pump runs for five minutes, then the timer turns off the power to the water pump, functioning like a breaker. The pump must be reset manually like a breaker.

Resetting the breaker: Ideally, this timer circuit would reset automatically once water pressure is restored, but that is much more complicated as it would require the deactivated pump to be turned on again or some other system employed.

 

This is a request for comments from those of you out there who have either considered this issue or who would like to develop a solution. I propose that a timer circuit be introduced between the breaker and the pump to serve as a safety device. It would be unobtrusive as long as the water was not to remain open for more than the timer duration. I am not a circuit designer, but I have been researching homebuilt circuits that might work.

--

Steve Bode, Sailing Vessel Intention

Amel Super Maramu #117 (1994) 

Western Mediterranean

+1 415-710-6659 voice/text/whatsapp

 

Matt Salatino
 

I’ve seen some boats use an ordinary light timer, available in any hardware store. They crank it on when they use the water system, and it times out, shutting off the pump. There is also a device made specifically for this purpose for boats.
This device would need a relay to operate a higher amperage pump:

On May 11, 2020, at 7:51 AM, Steven Bode - SV Intention 1994-SM#117 <steve@...> wrote:

FRESH WATER SAFETY SHUTOFF SYSTEM REQUEST FOR COMMENTS

Amelians, I believe that there is a serious issue with the fresh water pump system on the Super Maramu and I would like your input. 

The problem: In the event of a failure of the pressurized freshwater system — a break anywhere in the water plumbing, the entire freshwater supply could be drained overboard resulting in (a) loss of critical freshwater, (b) overuse of the freshwater pump (killing it) and (c) over use of the main bilge pump (killing it, too). Don’t ask me how I know.

Situational description: The freshwater pump may be left on. This is often the case when people are onboard, for example overnight or sometimes when they are ashore (off the boat).

The pump will pressurize the water system and remain off as long as the system remains pressurized. The pump will activate automatically any time there is a drop in water pressure.

If there is a break in the pressurized water system — a fault, then the pump will activate and run continuously until it is switched off, draining the entire fresh water supply into the bilge where it will be pumped overboard by the main bilge pump. This is a costly occurrence or possibly a safety issue if fresh water can not be resupplied, for example if the boat is off shore and there is no water maker.

A Proposal: A safety mechanism is needed to prevent this. A simple solution would be a timer that is activated every time the pump is activated. When the timer expires the pump is automatically deactivated until the system is manually reset. By determining the average time the pump is running each time it is activated, the timer could be set to shut off the system whenever above average run time is encountered. For example, if the pump typically runs for an average of 60 seconds, then the timer could be set for five minutes. If the pump runs for five minutes, then the timer turns off the power to the water pump, functioning like a breaker. The pump must be reset manually like a breaker.

Resetting the breaker: Ideally, this timer circuit would reset automatically once water pressure is restored, but that is much more complicated as it would require the deactivated pump to be turned on again or some other system employed.

 

This is a request for comments from those of you out there who have either considered this issue or who would like to develop a solution. I propose that a timer circuit be introduced between the breaker and the pump to serve as a safety device. It would be unobtrusive as long as the water was not to remain open for more than the timer duration. I am not a circuit designer, but I have been researching homebuilt circuits that might work.

--
Steve Bode, Sailing Vessel Intention
Amel Super Maramu #117 (1994) 
Western Mediterranean
+1 415-710-6659 voice/text/whatsapp
 

Gerhard Mueller
 

It is far easier to use faucets or water taps equipped with micro switches. The micro switches operate a relay to start/stop the pump. So the pump only runs when a faucet is opened. You can get such faucets with micro switches e.g. from Whale.
--
Gerhard Mueller
Amel Sharki #60
Currently Kalamata, Greece

Arlo
 

On my last vessel  51 footer I used wall mounted timer from.McMaster carr that you could turn the dial from 15 to 120 minutes and then it would open the contacts electrically thereby turning off the water pump electric. It was placed by the galley sink. It worked flawlessly with daily use for 10 years. The reason we installed it was to ensure when we left the vessel that the water was turned off. On my Mango my SOP is simply turn off the water when I leave the boat. We have a bilge alarm when the water gets high for when we are onboard. 

william reynolds
 

 we suggest you always kill the power  to the fresh water pump when leaving the boat.We check all clamps on the fresh water system every 6 months. I keep the water pressure at about 40 psi to reduce pressure on all water components. A final note, all Shurflo and Jabsco pumps have tiny check valves on the inlet and outlet. They do not tell you about this. Any tiny particles can lodge in these valves and bleed off the system pressure. The symptom of this problem is an infrequent cycling of the pump with no apparent leaks. I have always installed a prefilter on my fresh water system and have rarely had a pump problem. See attached pic CloudStreet
Bill Reynolds SM2K 331

Patrick McAneny
 

William , I have that problem , my pump cycles on for a maybe two seconds every five minutes or so. I have looked everywhere for a leak and finally concluded it had to be a leak in the pump, allowing water to go back to the tank. Can the check valves be accessed to clean ? 
Thanks,
Pat
SM Shenanigans


-----Original Message-----
From: william reynolds <sail23692@...>
To: main@amelyachtowners.groups.io
Sent: Mon, May 11, 2020 9:19 am
Subject: Re: [AmelYachtOwners] FRESH WATER SAFETY CUTOFF

 we suggest you always kill the power  to the fresh water pump when leaving the boat.We check all clamps on the fresh water system every 6 months. I keep the water pressure at about 40 psi to reduce pressure on all water components. A final note, all Shurflo and Jabsco pumps have tiny check valves on the inlet and outlet. They do not tell you about this. Any tiny particles can lodge in these valves and bleed off the system pressure. The symptom of this problem is an infrequent cycling of the pump with no apparent leaks. I have always installed a prefilter on my fresh water system and have rarely had a pump problem. See attached pic CloudStreet
Bill Reynolds SM2K 331

Matt Salatino
 

I believe it’s the valves in the diaphragm. It’s usually a gang of 3 or 4 valves that are replaced as a set on a common “diaphragm”. Easily replaced, and spare part at most chandleries or from Amazon/EBay. Replacing that part fixes the problem.

~~~⛵️~~~Matt

On May 11, 2020, at 3:38 PM, Patrick McAneny via groups.io <sailw32@...> wrote:

William , I have that problem , my pump cycles on for a maybe two seconds every five minutes or so. I have looked everywhere for a leak and finally concluded it had to be a leak in the pump, allowing water to go back to the tank. Can the check valves be accessed to clean ? 
Thanks,
Pat
SM Shenanigans


-----Original Message-----
From: william reynolds <sail23692@...>
To: main@amelyachtowners.groups.io
Sent: Mon, May 11, 2020 9:19 am
Subject: Re: [AmelYachtOwners] FRESH WATER SAFETY CUTOFF

 we suggest you always kill the power  to the fresh water pump when leaving the boat.We check all clamps on the fresh water system every 6 months. I keep the water pressure at about 40 psi to reduce pressure on all water components. A final note, all Shurflo and Jabsco pumps have tiny check valves on the inlet and outlet. They do not tell you about this. Any tiny particles can lodge in these valves and bleed off the system pressure. The symptom of this problem is an infrequent cycling of the pump with no apparent leaks. I have always installed a prefilter on my fresh water system and have rarely had a pump problem. See attached pic CloudStreet
Bill Reynolds SM2K 331

Ryan Meador
 

On my last boat, I had exactly the scenario you suggest happen: a hose let go while I was away from the boat, the entire water supply was pumped into the bilge, and the pump's diaphragm failed.

I recently had to replace the pressure switch on our SM's AMFA water pump, which is a standard Square D switch.  Rather than exact replacement, I used the FSG2J24M4BP, which has a low-pressure cut off.  If a hose lets go, the pressure drops to such an extent that the pump will turn off and not turn on again until you manually flip the switch.  This should prevent the worst of this type of problem, but it won't protect against slow leaks.

Thanks,

Ryan and Kelly
SM 233 Iteration
Boston, MA, USA


On Mon, May 11, 2020 at 8:04 AM Arlo <svplanb@...> wrote:
On my last vessel  51 footer I used wall mounted timer from.McMaster carr that you could turn the dial from 15 to 120 minutes and then it would open the contacts electrically thereby turning off the water pump electric. It was placed by the galley sink. It worked flawlessly with daily use for 10 years. The reason we installed it was to ensure when we left the vessel that the water was turned off. On my Mango my SOP is simply turn off the water when I leave the boat. We have a bilge alarm when the water gets high for when we are onboard. 

Thomas Kleman
 

We went with the SOP solution; keep the breaker off. Additionally, the fresh water pump LED goes green when the breaker is pushed in vs when the pump is active.....it helps me remember to turn it off.

Tom and Kirstin
SV L'ORIENT
Cruising Oahu, Hawaii

Nicolas Klene
 

Hello Steve
I like your safety minded approach ! I am not electronically   inclined In any way unfortunately ,but I would like to follow your progress and participate if I can .
Nick
Nicolas Klene
DarNico
SM2K # 471
In Marseille

greg greg
 

there are no simple solutions. the leakage can appear anywhere in the system. the discharge can be fast or slow, it can be regular or occur in specific condition (of temperature for example).
the timer is not the solution as it can cut the water when you are just second or third taking shower.
the only way is to implement AI to distinguish leakage loss from normal water consumption.
kind of analysis of presence of crew, times of running for FW and bilge pumps etc.

the only reasonable way is to switch it off when needn't and, when on,  watch FW and bilge pumps indicators as you must do for all other things as a responsible sailor under COLREG-72.