Lost fresh water pressure, what to check?

Mightychan

Mightychan

Member
Oct 8, 2016
157
Panama City FL
Boat Info
2005 DA 420, AB Dink
Engines
Cummins 6CTA
We lost fresh water pressure about half way through the day yesterday. The tank has plenty of water and the pump is on at the DC panel. What should I check first? Is there some sort of demand switch that is separate from the pump? And where is the pump located? Thanks!
 
I can hear my pump running when it's on, do you not hear yours? Mine is in the forward cabin, same place as my freshwater tank, perhaps yours is in the engine compartment and that's why you don't hear it?
 
Pumps are always relatively close to the tank. Your manual likely gives you a more exact location, though.

Check the screen filter on the pump.

Remove the output hose at the pump or the inlet at the water manifold - does it pump water?
 
Do you get any air bubbles coming out of your faucets? Any leak on the suction side (between the fresh water tank and the pump) will kill the pump's ability to develop any appreciable pressure. As for a separate demand switch, I've never seen any that aren't part of the pump. Once you find your pump, you should be able to identify that switch mounted on the end of the pump by the fact that the wiring goes through the switch, similar to this:
1694922864531.png
 
Found it, and it's dead. The parts manual lists it as a 3.3GPM Shureflo with a SeaRay part number 1128172. Any idea of what the current direct replacement for that pump would be?
 
Wondering if someone can help please I have a 2008 DA38 and the fresh water pump keeps cycling every 5 seconds. I notice water continuously seeping out of the thru hull vent on the PORT side. It’s midship just under the vent port. It’s the aft thru hull out drain of the 3 that are located there. According to the diagrams it’s the galley sink and head floor drainage system. I’ve had the hot water tank panel off the sink panel off and the head under sink panel off and no sign of leaks! I’ve used an endoscope to see if I can see water leaking but nothing? The bilge is dry in all compartments and the manifold is not leaking. I’m not sure what else I can do? I’ve attached a photo of the thru hull fitting that leaks water out whenever I turn on the fresh water pump or connect city water. There are no visible damp areas in the entire boat but it’s definitely leaking out of the thru hull exit. Appreciate any input !
 

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I'm not familiar with your boat, but I have a bit of time at the moment, so let's see if we can crack this nut. First of all, I think by talking out loud. None of my comments are meant to demean or anything like that. Let's go.

When the breaker for the freshwater pump is "ON", the pump will come on and run until the pressure switch is satisfied. When you turn on a faucet, pressue is relieved, thus the pressure switch tells the pump to come on to build the pressure back up. When you close the faucet, the pump continues to run until the pressure switch is satisfied again. That's how things are supposed to work.

The diagram you shared is for the drainage system, at least that's how it seemed to me. You say that you see water "seeping" out one of the thru-hull drains. But it doesn't seem likely that supply water can get into the drain system with you seeing the galley faucet leak (drip) or the like. Your owners manual will have a picture of the boat with the thru-hulls on it and you can nail the culprit down. It's in the front part on the manual.

Had you just filled the fresh water tank by chance after previously running it dry? You could have an air lock in the pump. Does water flow "normal" if you open the galley sink faucet, or any other faucet or water valve for that matter?

Is the screen filter on the suction side of the fresh water pump on securely?

Have you checked and double checked all other places that you can get water from your boat: anchor locker washdown, engine room washdown, lazerette (trunk) washdown, cockpit hand held shower. Make sure all are securely closed.

This is what I would look at first.

Keep us posted.

Jaybeaux
 
Electricjetman787 said:
Wondering if someone can help please I have a 2008 DA38 and the fresh water pump keeps cycling every 5 seconds. I notice water continuously seeping out of the thru hull vent on the PORT side. It’s midship just under the vent port. It’s the aft thru hull out drain of the 3 that are located there. According to the diagrams it’s the galley sink and head floor drainage system. I’ve had the hot water tank panel off the sink panel off and the head under sink panel off and no sign of leaks! I’ve used an endoscope to see if I can see water leaking but nothing? The bilge is dry in all compartments and the manifold is not leaking. I’m not sure what else I can do? I’ve attached a photo of the thru hull fitting that leaks water out whenever I turn on the fresh water pump or connect city water. There are no visible damp areas in the entire boat but it’s definitely leaking out of the thru hull exit. Appreciate any input !
Click to expand...
Your galley sink thru hull only drains the galley sink, the head floor drains to the sump, the sump should have it's own thru hull for discharge. If you have some one to help just pour a glass of water down each drain and confirm which thru hull is for what.

A common cause for a problem like yours is the hot water tank pressure relief valve leaking, which causes the water pump to kick in, it's often piped to it's own thru hull for discharge.
 
Jaybeaux said:
I'm not familiar with your boat, but I have a bit of time at the moment, so let's see if we can crack this nut. First of all, I think by talking out loud. None of my comments are meant to demean or anything like that. Let's go.

When the breaker for the freshwater pump is "ON", the pump will come on and run until the pressure switch is satisfied. When you turn on a faucet, pressue is relieved, thus the pressure switch tells the pump to come on to build the pressure back up. When you close the faucet, the pump continues to run until the pressure switch is satisfied again. That's how things are supposed to work.

The diagram you shared is for the drainage system, at least that's how it seemed to me. You say that you see water "seeping" out one of the thru-hull drains. But it doesn't seem likely that supply water can get into the drain system with you seeing the galley faucet leak (drip) or the like. Your owners manual will have a picture of the boat with the thru-hulls on it and you can nail the culprit down. It's in the front part on the manual.

Had you just filled the fresh water tank by chance after previously running it dry? You could have an air lock in the pump. Does water flow "normal" if you open the galley sink faucet, or any other faucet or water valve for that matter?

Is the screen filter on the suction side of the fresh water pump on securely?

Have you checked and double checked all other places that you can get water from your boat: anchor locker washdown, engine room washdown, lazerette (trunk) washdown, cockpit hand held shower. Make sure all are securely closed.

This is what I would look at first.

Keep us posted.

Jaybeaux
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Hi and thank you for your prompt response I do appreciate it. The culprit turned out to be the pressure relief valve on the hot water tank venting thru the thru hull drain. It was an Attwood 6 gallon factory heater. I have exercised it and put some WD40 silicone into it and the leak has completely stopped. Access to the heater was from under the stairs thru the vent grille.

It’s been a very long process opening hatches and looking for every hose! Attached is a photo of the culprit just in case it happens to anyone else ! The part number is

Atwood 90028 3/4 Inch Pressure Relief Valve​

 

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Jaybeaux said:
Woody gets the prize!
Click to expand...
Electricjetman787 said:
He certainly does!!
Click to expand...
I've told my Wife that I may have helped a fellow boater in dire need. She was impressed that I was able to do so from thousands of miles away.

She looks at me differently now, I think a new twinkle in her eye...this good deed may pay dividends;)
 
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