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TCL · 26-05-2020, 08:44

I have a Jabsco ParMax4 pump and a Jabsco 1L accumulator tank -- which system has worked fine for several years.

Just recently (past week), the pump has begun cycling much more often while the water is running.

I thought perhaps the accumulator tank bladder needed air added. (When I bought the boat several years ago, I replaced an accumulator tank with a busted bladder.) So I attached a bike pump and -- gingerly, out of fear of bursting the bladder -- tried pumping a bit of air. The bike pump is a foot pedal with a gauge built in, and it showed around ~40 psi on the downstroke. I gave it a few pumps, pushed the gauge up to ~60 psi a couple of times. I may have added a bit of air, but I don't think much -- leading me to believe that the bladder was not low on air.

More importantly, it didn't make any difference. Pump is still cycling much more often than before -- every couple of seconds -- while water is running.

I'd welcome any thoughts or suggestions on what I can check next as possible cause.

Again, this setup worked fine for 3+ years. Thanks.

dougweibel · 26-05-2020, 09:45

Do you have a water filter installed either before or after the pump? A dirty filter cartridge causes my pump to cycle in a similar manner.

Sailing August · 26-05-2020, 10:07

Check your pressure solenoid switch. This switch will measure the pressure and turn the pump on and off. The on and off settings should have some space between them to avoid quick cycling of the pump while the water is running.
These switched often fail but they are cheap. Consider a solenoid switch form the Granger catalog as a replacement. They are often cheaper and come with better pressure setting adjustments.

Cavalier · 26-05-2020, 10:13

Did you have the system pressured down when you adjusted the accumulator?

If the tank pressure requires adjustment after installation, ensure first that the pump is switched off and that an outlet is open, so that there is no pressure in the system.

Check the accumulator tank performance in this way every 6 months, and adjust the pressure if necessary.

Your optimum accumulator pressure should typically be set around 0.2-0.3bar (3-4psi) below the pump cut-in pressure. So if your cut-in pressure is 40psi, then set the accumulator bladder pressure to 36psi.

Then turn the water-pressure system back on.

Also, as mentioned above - check that your strainers and filters are clear/clean within the system.

ranger58sb · 26-05-2020, 10:40

Yes, more frequent cycling while water is running could indicate your accumulator bladder has lost air pressure or even gone completely south.

Yes, you need to completely depressurize the system before you make adjustments.

Last I heard, Jabsco recommends your bladder pressure by about 2-lbs over the pump's cut-in pressure. IOW, if pump cut-in is 20 psi, accumulator pressure of 22-lbs is supposed to be nifty.

Accumulators don't last forever; you may have gotten your money's worth.

-Chris

TCL · 26-05-2020, 18:23

Thanks for all the responses. Yes, there's a filter before the pump; I'll first check that in the morning.

Then I'll make sure to depressurize the system before doing any further fiddling. Thanks for that reminder; I had indeed forgotten when fooling with the accumulator tank earlier.

Thanks again.

**Lepke** · 26-05-2020, 22:42

Most pumps have check valves to hold the pressure when the pump is off. If the valve leaks, the pressure drops and the pump comes on. The valve could have dirt in it or be damaged.

tangara · 27-05-2020, 08:11

Clean the valve seat of the w pump by removing the pump head before spending money, as previously mentioned filter before the pump is a great help.

garychurch · 27-05-2020, 08:23

I had a similar problem. Fixed by replacing pressure switch and adjusting on and off as well as the pressure differential between the two.

mvmojo · 27-05-2020, 08:34

High probability it's the built in check valve in the pump. To test, run the water until the pump comes on, shut off the water. Let sit for 10 min or so and see if the pump kicks back on. If it does, it's the check valve.

Bill Seal · 27-05-2020, 08:45

Quote:

Just recently (past week), the pump has begun cycling much more often while the water is running.

Probably blown bladder.

**a64pilot** · 27-05-2020, 09:29

Quote:

Originally Posted by Bill Seal

Probably blown bladder.

I go with filter, because with a clogged filter the pump will hit its cut off pressure fast and turn off, then back on as a little water is used, hit pressure and cut off, etc, same as if there is no accumulator.
I personally don’t like accumulators. I believe variable speed pumps and or speed controllers are now reliable enough that they are viable.
I’ve been using one as a boost pump for my watermaker and am very happy with it, is a 5 gpm pump but supplying 1.6 GPM it runs very quiet and low amp draw.