Fresh Water pump running continuous.

Escapade

Escapade

Well-Known Member
SILVER Sponsor
Jan 10, 2007
1,260
Lake Michigan
Boat Info
44 Sundancer
Engines
QSC500
RE: 05 390 Dancer. We have just noticed our fresh water pump running continuous any time it is switched on. I found a screw on the bottom valve that appeared to be an assumed ( Pressure ) adjustment but, a few turns either way had no impact. Before I swap out I would like to get deeper into this in case a fix is available. Has anyone tackled this scenario already and what was your resolution to the problem. Thanks, Mike
 
You most likely have a small leak somewhere in the system. Time for more investigation........the freshwater tank is not empty?

Also make sure the filter screen at pump intake is clean.
 
Mine does that if I run the tank dry, until I bleed the air out of all the faucets. After bleeding all is normal again.

Sent from my Nexus 7 using Tapatalk 4
 
There often times is a "accumulator tank" in line on boats that size. I have replaced mine after it developed a water leak.
 
The boat is 8 years old. The pump has a shut off switch that may be stuck. You may be able to buy a replacement switch or repair kit. Myself @ 8yrs old I would just replace it for about $150.
 
rwf said:
Mine does that if I run the tank dry, until I bleed the air out of all the faucets. After bleeding all is normal again.

Sent from my Nexus 7 using Tapatalk 4
Click to expand...

I second this. If the tank was run dry you may have air trapped in the line. Try running the pump with all of the faucets open for a few minutes to bleed the system.
 
Everyone covered the possibilities well - it's either a problem with the pump itself (probably least likely in my opinion - I've seen these pumps die completely but I haven't seen one get stuck in a run position), air trapped in the lines, or a leak. Some trial and error/experiments are needed to figure out which one. You could, of course, replace the pump and see if a new pump also runs continuously, that would pretty much eliminate the pump (and you get a new pump in the process). I had the same thing happen on my 05 '390 and it turned out to be a small leak by the way. PS - The screw is definitely going to be pressure adjustment, and no matter which of the three possibilities it is above adjusting the pressure isn't the fix/answer. Good luck!
 
I have the same problem. Mine leaks a little water and so the pump keeps priming itself. Winter project to fix it.
 
Escapade said:
RE: 05 390 Dancer. We have just noticed our fresh water pump running continuous any time it is switched on. I found a screw on the bottom valve that appeared to be an assumed ( Pressure ) adjustment but, a few turns either way had no impact. Before I swap out I would like to get deeper into this in case a fix is available. Has anyone tackled this scenario already and what was your resolution to the problem. Thanks, Mike
Click to expand...

Check the filter. A clogged one can cause your problem. BTDT.

Could be the diaphram. BTDT

If it is original, you may want to upgrade. I did and am very happy. Relocated it out of the ER for easy accessability too. Better water flow and lower current draw.

My 2 cents
 
jff said:
Everyone covered the possibilities well - it's either a problem with the pump itself (probably least likely in my opinion - I've seen these pumps die completely but I haven't seen one get stuck in a run position), air trapped in the lines, or a leak. Some trial and error/experiments are needed to figure out which one. You could, of course, replace the pump and see if a new pump also runs continuously, that would pretty much eliminate the pump (and you get a new pump in the process). I had the same thing happen on my 05 '390 and it turned out to be a small leak by the way. PS - The screw is definitely going to be pressure adjustment, and no matter which of the three possibilities it is above adjusting the pressure isn't the fix/answer. Good luck!
Click to expand...

If turning the scew to turn pressure down doesn't shut off pump then the diapham is no good I had the same problem I replaced the pump and all is well. With the pump running continuously the tank would empty and there would be visable water showing somewhere if it was a leak. Just my past experiNce
 
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Speaking of water pump issues I have one also. When the pump first kicks on after not being at the boat and pressurizes it sounds like it is aerating for up to 10 seconds then will vibrate and start building pressure. Even after it builds innitial pressure it has a vibration and spool up that it goes through. No traces of leaks anywhere that I have noticed. Icemaker isn't making ice while were away either. I used to be able to shut the pump off for a week and not lose any pressure. That was a good feeling.
So my thoughts are possibly the pressure switch or the pump itself going out. I also notice a pulsation in the water sometimes. Expansion tank is new 2 years ago. Pump is original Shurflow 3.3gpm. Thoughts???
 
As a side note, either to the OP or anyone reading in the future, I have had one of these pumps apart as a learning experience. They are, in my opinion, very complex. I'm not sure if you can even find the correct replacement parts or kits, but if you venture into the guts of one of these, keep a close eye on how it comes apart.

I would also caution about playing too much with the adjustment screw. Crank it up too high and you could do more harm than good.
 
Escapade said:
RE: 05 390 Dancer. We have just noticed our fresh water pump running continuous any time it is switched on. I found a screw on the bottom valve that appeared to be an assumed ( Pressure ) adjustment but, a few turns either way had no impact. Before I swap out I would like to get deeper into this in case a fix is available. Has anyone tackled this scenario already and what was your resolution to the problem. Thanks, Mike
Click to expand...

Also check your Hot water heater pressure relief valve. See if there is any water coming out of one of the thru hulls on the port side. Good Luck
 
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