Shureflo aqua king 3901 0212 problem

[lesrollins]

Hi

We have a shureflo aqua king 3.0 fitted to the boat. It as just developed a problem where it will not switch off.

1. I have changed the accumulator and it is set at the correct pressure between 12 -15 psi

2. There are no leaks anywhere

3. I have checked the prv valve on the calorifier to ensure it as not stuck open

 

Now I am stuck as to why the pump will not switch off as anyone got any ideas or suggestions

Thanks

[lesrollins]

Even with both valves switched off either side of the pump it keeps running

[David Schweizer]

The most likely culprit is the tiny check valve switch located inside the housing on the front end of the pump. the valve can get clogged with lime scale and stop the switch from closing. The remedy is to carefully remove it and brush the limescale off with a soft toothbrush and re-assemble.

 

I am not familiar with the newer style of pumps but from the exploded diagram, the new ones look very similar to the old 2088 series, although you may have to buy a complete switch unit if it will not dismantle. Exploed diagram here:- http://www.keller-pumpen.de/fileadmin/user_upload/Download/Membranpumpen_Datenblatt_3901-0206_und_3901-0216_SHURflo_KELLER-Pumpen.pdf

 

P.S. If you have to replace the pump, look for a Shurflo Trail King which is identical to the old style Aqua KIng, except that the Trail King has an aluminium body, wheras the Aqua King has a bronze alloy body, which is only required in a salt water environment.

Edited June 4, 2016 by David Schweizer

[Claude]

You're sure there's water in your tank of course?

[IDS]

what does the accumulator pressure read when the pump is running?

[lesrollins]

Yes there was water in the tank Claude. I changed the pump for a spare and everything is now working as it should. Is it worth repairing a pump or just better to go for new and if so which one. What's the jabsco like

[Chewbacka]

Yes there was water in the tank Claude. I changed the pump for a spare and everything is now working as it should. Is it worth repairing a pump or just better to go for new and if so which one. What's the jabsco like

Pressure switches are not anywhere as expensive as a new pump. I know what I would do

[Phil Ambrose]

There should be no water on the side of the diaphragm where the pressure switch lives. I have I'm the past persuaded a pump to work by WD40 to free up a sticky micro switch and again by changing a knackered switch with a new one, cheaper than a new pump.

Phil

[IDS]

Definitely change the switch if you can get at it. They are only a few pounds. Make sure you get one with the same 'amps' rating as the one you are replacing, there are a lot of lower rated micro switches that look the same.

[David Schweizer]

I would change the switch which is quite an easy job, but if you are going to remove it, try cleaning it first as suggested in my earlier post. I have alway found that to work, and the spare switch is still in the spares box!

[Markinaboat]

Probably not what you want to hear but I put in a new Aqua King once and it failed after just a few months. The chandlers replaced it and that went too. They replaced it with another well known make (4yrs and still perfect on a liveaboard) as they had so many problems with them, they stopped supplying them. I called the company that manufacturers them and even they told me they were problematic!

[lesrollins]

So what did you replace it with Markinaboat

[Markinaboat]

Jabsco parmax 2.9. Had a parmax 3.5 but was deafeningly loud. Again, Xylem admitted it was noisy and at the time, they were working on a resolve.

 

2.9 conserves water and very quiet/inoffensive:

http://www.marinescene.co.uk/product/1526/jabsco-par-max-2.9-(12volt)-pressurised-water-system-pump/?gclid=CJy4ytjblMYCFQOL2wodE2YAqg

Edited June 7, 2016 by Markinaboat

[lesrollins]

Thanks Markinaboat I have just purchased a jabsco Parmax 2.9 from norbury wharf it's now fitted. I must say you were right it's a lot quiter than the shureflo and it switches off more or less straight away when the tap is closed. Cheers for that.

My next mission is to play with the shureflo and inspect the gubbins after removing the four screws holding the micro switch casing how do I get into the micro switch as it appears to be a sealed unit.

[Phil Ambrose]

Thanks Markinaboat I have just purchased a jabsco Parmax 2.9 from norbury wharf it's now fitted. I must say you were right it's a lot quiter than the shureflo and it switches off more or less straight away when the tap is closed. Cheers for that.

My next mission is to play with the shureflo and inspect the gubbins after removing the four screws holding the micro switch casing how do I get into the micro switch as it appears to be a sealed unit.

Split the pump and undo more screws, ignoring the " no serviceable parts"warning. You will find a sort of plastic yoke which pivots, one end fits on the diaphram end of things and the other end works the microswitch, the yolk can get sticky as can the microswitch, ss what you can do withWD 40.

Phil