Accumulator tank

[Tony Benoit]

Dear Forum Readers and Writers,

Here's an update on my pump problem (futile cycling). 

History: About every 3 minutes, the pump comes on for about 2 seconds.  The noise is annoying, sometimes even startling.

I had previously checked for leaks in the downstream tubing.  I couldn't be absolutely sure, but I couldn't find any sign of leakage or water loss/accumulation in the bilge.  I disconnected the pump outlet at the first T and blocked it off.  (So, I had a 2 foot stretch of deadended pipe attached to the pump outlet).  The pump cycled on for about a tenth of a second every few seconds.  If I squeezed the blocked hose (ie, put back pressure on the pump), the pump would switch on immediately on release of the pressure.  To me, these symptoms suggested that the pump is losing pressure backwards through itself.

Latest: I just spoke with Dave in Technical Support at ITT/Flojet.  He confirmed that the problem sounds like a broken, dirty, or jammed check valve in the pumphead (NOT the separate check valve downstream in the plumbing system).  A replacement check valve is included in the Pump Service Kit, part no. 21046-057.  Defender has never heard of this part number, and Dave warned not to try something else: The pieces may or may not fit.

I found that part number at ABS Alaska of Washington state and ordered it.  I had tried calling a distributor in New York state, but could not get through to anyone who could help me (kept going to hold).

I will let you all know how the rebuild goes.

Thanks,

Tony
================
Helen C
#903 '89

[Roc]

Tony,
I've noticed my fresh water pump to cycle every so often.  I checked for leaks but never found any.  I never found a solution, but came up with a theory as to why this was happening with my system.  The end result is I've done nothing about it since it occurs infrequently and when the pump cylcles, it lasts about 2 seconds.  Here is my logic and what I figured.....I need to clean my galley faucet airator often because it becomes clogged with mineral/calcium deposits that restrict flow.  I also realized that my pump cycling never happens at the beginning of the season, but would start to happen into the middle of the season, like around July.  It then occured to me that if the airator got clogged with deposits, then over time, the same thing would happen to the pump diaphram as the season went on.  If the diaphram wasn't seated tightly, then a small amount of water would trickle through and cause it to cycle to keep the pressure up.  I asked myself why would the diaphram be clean at the start of the season....well, I figured the commissioning that I do to the water system (Peggie Hall's method) of using bleach and letting it sit over night, then purging the tanks over and over again might clean the diaphram out. 

So....I've never confirmed that this is the case with my cycling issue, but since there are no leaks, and this has now been the situation for almost 10 years, I've let it go....

[Ron Hill]

Roc : Look at my previous post. 
I believe that you need the finer strainer and that should solve your problems!!  A thought

[Tony Benoit]

Hi All,

I called FLOJET's tech service and talked to Dave.  He told me that the short-cycling sounds like a bad check valve in the pump head.

From ABS Alaskan in Washington state I got FLOJET Part No. 21046-057, a pump rebuild kit.

I rebuilt the pumphead, though after I got started I could see that I could have more easily just swapped out the check valves.  In oldWithBadORing.jpg, you might be able to see the slight kink in the o-ring (topleft corner).  OldAndNew.jpg shows the pumphead with the new check-valve in place.  The old one is lying in front of it.

After I reassembled the pump, the short-cycling seems to have disappeared.  Also, it used to be that when I flicked on the Water Pressure switch, the pump would run for about 3 seconds.  Now it seems to hold pressure even when off.

If you rebuild your FLOJET, be sure to completely remove the pumphead from the motor before you start to disassemble it.  There is a lock screw on the shaft (allen head) which you can access through a little slot on the pump housing.  You may need to remove the mounting platform from the motor to get at the slot.  If you don't take the pumphead off the motor, you will be tempted (as I was) to force some of the parts to disengage from each other.  Turns out that they are screwed on but you can't see the screwheads until the pump is off.

Note: If you just want to swap out the check-valve, just remove just the top half of the pump.  The old one can be easily popped out.  You might even get away with just replacing the o-ring.

Enjoy,

Tony
======================
Helen C
'89 Standard/Wing #903

[Stu Jackson]

Now it seems to hold pressure even when off.

Tony,

Nice report, thanks, and glad you fixed the issue.

I suggest that you get in the habit of opening (then closing) a faucet after you turn the power off to the pump, especially when you leave the boat.  No need to have the pressure stay in the system when you're not there.