Fresh Water Pump Problems...please help

I just purchased a 2002 Larson Cabrio 274 which has a sink in the galley, a sink in the head, a sink in the cockpit area, and a transom shower. The problem I'm having, is low water pressure. The pump will run to build pressure then shut off once it reaches operating pressure. I get water flow, but when I try to use the spray feature on either the galley sink or the shower in the head, the pressure is so low that it won't keep in the spray mode...meaning the water just trickles out of the nozzle and once the button is released, it goes right back to normal (non spray). This is the case even when I'm trying to use any ONE of the faucets. The transom shower works a little bit better, but I'm wondering if it only does because it's closer to the pump.

Anyway, I'm just curious as to whether or not I have a bad pump incapable of building and maintaining the required pressure or if it's another problem that I'm just not aware of.

The pump that's installed is rated at 2.8 gpm and 45 psi and is the original pump installed on the boat from the factory. The boat only has 100 hours on it and I'm seriously doubting that the water system was used much.

Any help would be greatly appreciated!!

Thanks.

Re: Fresh Water Pump Problems...please help

Does the water system have an accummulator? This is a separate tank that the pump adds water to and in the process compresses air at the top of the tank. If this is the type of system you have, that tank may no longer be charged with air and is instead, full of water, so even though the system is pumped up to 45 PSI, the moment you open a tap, pressure drops to delivery pressure. See if you have that tank and if so, drain it. If there is a Schrader valve on it add about 10 PSI of air pressure. Then turn on the pump and see what happens. The air pressure will allow water draw down for a little bit before the pump comes on so the pump will cycle less often.

Re: Fresh Water Pump Problems...please help

It doesn't look as if it has an accumulator. Would the accumulator fix the pressure problem, or just smooth the flow out? I guess that my question is will the shower and galley faucet actually work in the spray mode by adding the accumulator or will it require a new/bigger pump? I'd rather spend the money on the pump instead of the accumulator and it not fix the problem.

I appreciate your help!!

Re: Fresh Water Pump Problems...please help

If the system doesn't have the accumulator then there are only two solutions to smoothing water flow. If the same size plumbing is used from the pump to the farthest fixture, that's part of the problem. Water systems, like heating systems, taper gradually to maintain flow the farther one gets from the pump. A typical home system for example has a 1-inch+ inlet to the home. A 3/4-inch feeder has 1/2-inch individual lines to the fixture, then stepped down again from the wall to the fixture. In other words, if the flow rate is restricted at the pump end, there is no way flow rate can be acceptable at the end of the line. That doesn't mean you need a larger diameter main line. It may need to be reduced at the far end, or increased at the pump end. Yes, a larger pump flow rate would help and yes, the accumulator would smooth the flow and reduce the rapid pump cycling. Accumulators for this type of system would be about the volume of a basket ball but obvously shaped more like a large bean can of the same volume. There is usually just one port at the bottom and a drain valve. As the pump runs, it pressurizes the accumulator while compressing the air in it. When the pump shuts off, it's the compressed air that forces water through the line until pressure drops to the turn-on point and the pump runs again.

Re: Fresh Water Pump Problems...please help

At 2.8 gpm and 45 psi that thing should have great pressure.Any guage to check that the pump is actually building up that much pressure?

Re: Fresh Water Pump Problems...please help

I think that I'll try to add an accumulator to the system.

As far as a pressure gauge...I'm sure that i can come up with something to test it out...great point!!

Is there any way to adjust the output pressure through a regulator or something or is the pressure controlled internally with the pump?

Re: Fresh Water Pump Problems...please help

The pump probably has an inlet screen filter. Odds are good it's clogged. Check that before you spend any money on it.

Re: Fresh Water Pump Problems...please help

The inlet screen was actually the first thing that I checked. It appeared to be free of debris and free flowing...but thanks to everyone for the great input!!

Re: Fresh Water Pump Problems...please help

Good luck with it.

And Welcome to Iboats! ( i think everyone forgot).8)

Before you add the accumulator, disconnect the line at the last fixture and then run the pump to see what kind of flow you actually have. If you have a 2.8 G/min pump, the pump should fill nearly three gallon milk containers in a minute or so. If not, the pump is not delivering the stated "volume" even though it may be capable of developing 45 psi. There may even be a restriction somewhere in the main line.

Re: Fresh Water Pump Problems...please help

also do the faucets, have filter screens on them, they may be clogged. the shower heads, have small restrictors, in the head, where i connects. even home showers heads have restictors, to cut wasting water. i always take mine out. i like lots of water when i shower.