Fresh water supply problems that are affecting my marriage...

[Zydeco IV]

Need help on a freshwater tank problem... I've recently installed a new Galleymaid pump. It works well except when we turn on high demand water equipment like the washing machine or dishwasher. When these units are turned on (singly, not simultaneously) the water system after a minute or so shuts down and the pressure drops to zero. When I flip the water pressure regulator switch the pressure comes back up to the 45 lbs I've set it at and it works great til I try to use it again for these uses. (FYI the washing machine and dishwasher both work fine when I'm operating off dockside water.) So I've isolated the problem to boat water supply only.

I'm thinking there must be a problem with trash or some kind of obstruction or build up in the water supply line between tank and pump. If this is the case what are the choke points I should check first to test the theory. And if it checks out what can I do about it? Is there a teatment or additive I need to put in the water? Or some kind of filter or strainer I need to install?

We cruising down in the Keys now and spending a lot of time on the hook. So my wife wants this matter resolved now. Like RIGHT now. Help...

[Beckytek]

I don't understand what you mean when you said you flipped the water pressure switch and the pressure came back up. The pressure switch should be on and in the circuit at all times so when the pressure drops the switch turns the pump on. It doesn't sound like you have a restriction because the pressure comes back when you flip the switch. If anything you may have an intermittent switch. You can check to see if the water flows from the tank by disconnecting the input to the pump. You should have a filter at that junction to prevent any junk from the tank getting into the pump. If the pressure goes to zero, then the switch is not doing it's job. I would check that first.

[Passages]

Sounds like a problem on the suction side. Couple quick checks...

You should have a strainer on the suction side of the pump. Is it plugged?
When flow stops, are the suction lines collasped?
Is the vent line clear?

That's where I'd start. Good luck.

[luckydave215]

Another possibility is that you have a low pressure switch in the circuit. The high demand appliances may draw so much flow that the system pressure drops below the low pressure "cut out" value, thus shutting down the pump. When you recycle the switch, it overrides the low pressure cut out, allowing the pump to build pressure again. Just a guess.

[Pascal]

beckyteck, the galley maid pump has a pressure switch which will shut down if pressure falls below a preset limit. when restarting the pump, you need to hold a lever on the swithc to build pressure above that cut off, 10 or 15psi i think.

i don't know if it's possible, but it seems like these appliances are using too much water causing the pressure to drop below the limit... what happens when you open multiple faucets ?

[Fanfare]

The "low pressure switch" is probably a dry tank switch, designed to prevent the pump from staying on and burning itself out when the water tanks are exhausted. You might try to put a restriction in the washer inlet lines which would slow the flow of water into the washer so the water pump has more time to keep a constant flow coming. If you have a valve on the washer inlets you could partly close them. Or, go to the hardware store and buy some washers with varying sized holes in the middle and put these into the washer line hose fittings. Most household washers are designed to operate at about 100 lbs of pressure, versus the 40 lbs or so on board. As long as the washer has a float switch to stop the water flow instead of a timer it shouldn't make any difference.

[spartonboat1]

might double check some of the many check valves in your system. I found one that was bleeding off some pressure by accident. Not really an issue, but it was not hold pressure. Just a thought..

[TedZ]

Standard Square D and other manufacturer's pump control switches have cut-in and cut-out set points and ALSO a low pressure cut out when the pressure falls below a certain point. These are commonly used on pumps and are the best. The little lever on the switch is the override to get the system started and up to the minimum pressure.

Simply modulate the flow of water to the washing machines with the shut off valves so they can only pass about half volume. Doesn't effect the washing machine a bit and will avoid the pressure falling too low when there is additional demand.

Ted

[GaryNW]

For modulating flow, your valves should not be ball valves (if 90 degree turn shuts them, they are ball valves). If you don't already have gate valves, should be cheap to replace the balls with gates.
Gary

[AquaNav77]

For the very same reason as stated, I cantacted Galley Maid on a retrofit and the suggestion was not to use the DC powered pump but to go with the AC version which provided more volume. I believe the difference was an additional 4 gal/minute. Pressure was set to 45 pounds as per their instruction and we never had a problem when showers, dishwasher and clothes washer were used. The DC system was very marginal. The AC system is 120/240 VAC and uses a larger stator on the pump end.

AquaNav77