Uneven water flow...

[ancora]

We have a Jabsco fresh water pump hooked up to an accumulator tank, but the water flow is uneven, from full flow, to just a trickle with the pump cycling on and off. Does this have something to do with the air pressure in the accumulator tank?

 

[Larry M]

Could be. The tank should have a Schrader (bicycle tire type) valve. Check the pressure the same way you would on a bike. Each tank size, style and manufacturer will have a recommended pressure for the tank.

 

[Capt.Bill11]

We have a Jabsco fresh water pump hooked up to an accumulator tank, but the water flow is uneven, from full flow, to just a trickle with the pump cycling on and off. Does this have something to do with the air pressure in the accumulator tank?

Do you have a inline water filter ?

 

[ancora]

No inline water filter.

 

[hmason]

Could also be the pressure switch on the pump.

 

[FlyWright]

Sounds like you've lost your accumulator pre-charge. Like Larry says, it could be an easy fix.

 

[HopCar]

My first thought is the accumulator tank is water logged and needs to be pressurized or replaced.

Another possibility is that your pump should not be connected to an accumulator tank. Some Jabsco pumps are variable speed and shouldn't be used in a system with an accumulator tank. It seems to confuse them. You can look up your pump on the Jabsco website or just post the model number here and I can tell you.

It might be the pressure switch, but probably not. They usually fail either off or on, not switching on and off.

 

[ulysses]

HopCar is absolutely correct on both potential culprits. If you are using your accumulator tank with the proper pump and you need to recharge the air be sure to turn the pump off and drain some water prior to recharging. Once a tank gets waterlogged and creates a cycling effect on the pump it is usually an indication of the air bladder inside being ripped/torn or holes in it that allow the air to mix with the water and eventually losing all or most of the air. The air charge and the pressure switch are somewhat matched.

If your pump is a variable speed "on demand" type it does often get confused with an accumulator tank.

 

[ancora]

I got the pump from the discard table at the club, and rebuilt it. Of course there was no accompanying paperwork on it, so I don't know whether it even needed the existing accumulator tank. Will have to so some research on it.

 

[HopCar]

Ancora if the label is still on it the model number will look like this: 12345-0000

 

[FlyWright]

I got the pump from the discard table at the club, and rebuilt it. Of course there was no accompanying paperwork on it, so I don't know whether it even needed the existing accumulator tank. Will have to so some research on it.

Sure hope its prior service was as a FW pump and not a macerator pump!!

 

[Peter B]

Sure hope its prior service was as a FW pump and not a macerator pump!!

Right on Al. Maybe it was a 'Trump Pump'..? Might be time old tightwad recycler ancora shouts himself a new one..?

holds out hand to be smacked, but he asked for it. After all he did say...

"I got the pump from the discard table at the club, and rebuilt it."

 

[FF]

For many boats this is normal.

The pressure tank will hold water at the highest pressure the pump is set for.

The pump will not turn on till the pressure is lowered to the pressure switch cut on point.

Perhaps 10 or 15PSI below full pressure.

At that point the pump is attempting to feed the open faucet , and also repressurize the tank.

IF the pump is undersized it may not even be able to maintain cut on pressure while the tap is wide open.

Too long a suction or pressure run with too many fittings will work even a great pump very hard .

IF it means a lot to fill the washer or dishwasher fast , or to take showers while using tap water a pair of pumps in parallel will be less costly than a real big pump, and perhaps use less electric with low water loads.

 

[ancora]

Goin' to the boat today and get some numbers off the pump.

 

[jleonard]

When my water flow gets like that I have to clean out the aerator screen. Even though I have a sediment filter sometimes they clog up.

 

[C lectric]

Is this recent?

I have a Groco accumulator. After 20+ years of good service I realized some thing was not right. Pump short cycling, no big shot of water. First thought was the bladder had given up.
Nope, but I realized the bladder had lost its air charge down to a level the bladder could not work. On my 1 gallon Groco the pressure must be about 18psi. After recharging to 18 psi it has been working fine for the last two years. Now I check it once a year.
That air valve, Schrader, is not forever and allows a tiny bit of air to leak out.

The system must be depressurized to check the bladder pressure. It needs to be set with no water pressure applied.

If it was working before then check the pressure before doing anything else.
If the pump is new to you and is showing the problem only after the new was installed then the other points may well apply, but find out first. Check the bladder charge pressure.

 

[ancora]

The pump is a JABSCO PAR MAX 3, Model #30600-0012. Found it in my 1996 JABSCO catalog, but no mention whether it needs an accumulator tank.

 

[HopCar]

The pump is a JABSCO PAR MAX 3, Model #30600-0012. Found it in my 1996 JABSCO catalog, but no mention whether it needs an accumulator tank.

Yes you want to use an accumulator tank with that one. I think we're back to a waterlogged accumulator tank.

 

[DHeckrotte]

Previous boat had a Jabsco water pressure pump. It appeared to have failed. I replaced it with another, new one and while doing so, found that those pumps have a small filter at the intake. Mine was dirty.

Make sure the filter's clean while you're groveling around in the crawl space.

 

[C lectric]

Or loss of air charge pressure.
If the bladder has failed then it,s a new accumulator time but be sure.

 

[FF]

Some "accumulators" that are about the size of a quart of milk have NO diaphram.

Over time the air is absorbed , so they must be repressured .

Drain the water , then hook it back up , is all you can do.

 

[Shoalwaters]

Sure sounds like the accumulator is not working. This means it is full of water or the membrane is punctured. If your accumulator has a Schrader valve, then try this: switch off the power to the pump and open any faucet. Allow water to stop flowing and leave faucet open. Connect a 12 volt air pump with pressure gauge to the valve and switch it on. Some water will flow from faucet. If reading on pressure gauge increases and HOLDS when air pump is turned off then you have recharged the accumulator. If it drops down to zero, the diaphragm is toast.

BTW: in my experience the little black plastic accumulators DO have a diaphragm inside. The above procedure works with them too.

 

[Lepke]

If you want city type constant pressure, you put a pressure regulating valve between the pump and accumulator and the rest of the system. The regulating valve is adjusted to house pressure (about 35psi) and the pump switch is adjusted to 45/60psi. You need a pump that can deliver 6-10 gallons a minute at 45psi, plumbing to the pump suction of 1", maybe 1-1/2", and probably 3/4" plumbing until you get close to faucets. Also the air psi of the accumulator tank needs to be higher.
I use a shallow well pump with a pressure regulator adjustable to 45/60.
All the accumulator tanks I have seen are good to 100psi.

 

[ancora]

Pumped more air into the accumulator and it does work better.