Jabsco PAR-MAX HD4 water pump Slow to Prime

[Sea-change]

Hi

I’ve just installed the Jabsco PAR-MAX HD4 12v (part# Q401J-115S-3A) after my Jabsco PAR-MAX 4 (part # 31620-7005) failed. The boat is a Lagoon 450 and 3 years old, the original water pump was installed when the boat was built.

I have a Jabsco accumulator tank which is part of the Jabsco 52520 - Series WPS Single Stack.

The new pump is slow to prime on 1 tap (faucet) which is the galley mixer with a pullout nozzle. This happens on both hot and cold. When I turn on the mixer, the pump runs but the tap slows to a small drizzle before the pump primes and starts to pump properly. This can take up to a minute or so. Occasionally the pump does not prime at all and I need to run one of the other taps to get it to prime. The old pump did not do this.

All other taps (all mixers) onboard (9 in total) function normally, with the pump starting and priming within seconds.

I have swapped out the galley mixer pull out hose for a new one as I thought there may be a blockage or a kink in it. No change. I also manually pressurised the accumulator tank to 18 psi as per instructions. No change.

There are no leaks in the system, I have checked every hose onboard and there are no leaks.

Any ideas as to why this is happening and how I can resolve it?

Thanks
Michael

P.S According to Xylem/Jabsco, the original Jabsco PAR-MAX 4 (part # 31620-7005) was superseded by Jabsco PAR-MAX 4 (part# 31620-0092) which in turn was superseded by Jabsco PAR-MAX HD4 (part# Q401J-115S-3A).

[sailormed]

My guess is that the rubber hose of the pull-out galley tap is playing tricks with the pressure switch of the pump. Can you adjust the pressure switch detection pressure?

[Sea-change]

Originally Posted by sailormed

My guess is that the rubber hose of the pull-out galley tap is playing tricks with the pressure switch of the pump. Can you adjust the pressure switch detection pressure?

I do not think this pump has an ability to adjust the pressure switch detection.

[Tupaia]

Have you bled the system. All outlets running for several mins then shut off one at a time.

Alternatively, bypass the accumulator altogether and see if the pump works ok, you may find you don't need it at all.

[Sea-change]

Originally Posted by Tupaia

Have you bled the system. All outlets running for several mins then shut off one at a time.

Alternatively, bypass the accumulator altogether and see if the pump works ok, you may find you don't need it at all.

I’ve bled the system many times and do so each time i start the pump.

Haven’t bypassed the accumulator yet, will try that today.

Just wondering if the new pump could have a faulty pressure switch, as I’m now seeing the same behaviour occasionally happening randomly on other taps.

[Ruso]

It cost me to buy a new pump. It was simple connector sucking in air from water tank to the pump inlet. Purging the system might help as well - water accumulator tank should have purging valve on top.

[sailjumanji]

Every issue I've had like this has been due to air getting into the system.

[GreenWave]

Agree you have an air leak and the diverted/mixer is likely the source.

[HopCar]

If I understand the problem, it sure sounds like a bad valve in the pump. Bad valve would make it hard for the pump to prime and slow to come up to pressure. It’s pretty unlikely in a new pump but if you’ve eliminated the other possibilities, check the valves.

[Celestialsailor]

Could also be debris in the pump head. I have seen Teflon tape do this

[moseriw]

With all these bloody useless pumps... try to mount it below the freshwater tank. Sometime it helps..
btw. I have a pump that is below the tank and I have to bleed it every time the tank runs out of water. And they dare to sell us this scrap!

[Scubaseas]

Same pump same problem. One time was crud under valve but all the faucets were effected. The other time I was pulling air on the inlet side. Not a lot but enough to make the pump run as you describe. All it took was a 1/4 turn of a hose clamp on an old splice the previous owner installed. I have found any air in the system, either before or after the pimp will confuse the pressure switch. My pump also likes a large accumulator with 20 to 25psi air pressure on the bladder. Taps the farthest from the pump are the least sensitive to air in the system. If you have hoses and clamps on the inlet side try tightening them.