Fresh water pump won’t shut off

Spyderweb

launched boat today.  Drove it 8 miles to home marina and began by setting up the water.  Got all the taps running clean water, normal pressure, and stopped spitting air.  But when all faucets were off, the pump continued to run.  The strainer on the pump shows a little bit of air at the top of it.  Don’t know if that’s normal.  I find no water leaks anywhere.  From experience I know with small leaks pump shuts off but will cycle back on every so often depending on size of leak.  For pump to not shut off at all, it would have to be a big, noticeable leak.   Any suggestions why pump won’t shut off?

Paul
2008 Rinker 330 

aero3113

If there isn’t enough water in your tank I think it will keep pumping till it has enough water to build pressure then shut off.

aero3113

When I turned my pump on for the first time this season it kept pumping (empty tank) as soon as I started to put water in the tank it built up pressure and stopped.

LaRea

But you had steady water at full flow, not spitting air, and then it wouldn't shut off?  And your bilge isn't running?  A small air bubble in the strainer wouldn't cause that.  I can't think of any reason other than a faulty pump.  How old is the pump?

Spyderweb

Actually bilge pump did come on originally.  Traced that to the drain for the water heater was left open.  Shut that off and everything started working at the faucets.  Flow was good, pump just wouldn’t shut off.  I’ve only had boat one season, but pump could be original.

Stodge

My transom shower was on and I didn't realize it.  So I had a similar issue this year.  Took a while to notice since it's behind a door.  The water just went into the bilge then out.

Liberty44140

Agree with comment above that your tank is too low. Also make sure all faucets and showers are off.

McGarnicle

If your hot water tank was empty you probably didn't have enough water in the tank to fill the lines and hot water tank so the pump kept running. Happened to me as well. 

Willhound

And on that topic, when you fill your water tank and start the pump to fill the system make sure the hot water tank relief valve is open to let air out as the tank fills. When water comes out the valve close it and you're good. Otherwise the tank won't fill properly and when you turn it on it will at best pop the reset on the tank or at worst blow the heating element or both. I learned from experience.

Spyderweb

Filled the water tank full this morning and turned on pump.  It kept running.  Turned on faucets.  Did get some intermittent spitting out of hot water tap, but then ran smooth.  Tried all faucets on at once.  All ran smooth.  Shut them off and pump kept running.

aero3113

It must be the pressure switch on the pump. You can try playing with it but will more than likely need to be replaced. I don't think you can buy just the switch.

raybo3

Sounds like the pressure switch is hung up. Give the pump a good rap with a butt end of a screw driver and see what happens. I bet the switch is just hung up.....

Spyderweb

Tried rapping the pump all over.  No luck.  Couldn’t figure out how to get into pressure switch.

i do wonder, if pump won't shut off, wouldn’t pressure really build up, and you’d have tremendous pressure in system?  Is there some kind of relief valve, like on the water heater? 

Anyway, I give up.  Will order pump this weekend.  Appears straight forward to install.  Only concern is if inlet and outlet fittings will be the same.  This one has the blue lever you pull and it releases the fitting.

jhofmann

Had the same issue, pump kept running, all valves closed, and no water leaks. Changed the pump and problem solved. I don't think that type of pump can build up too much pressure, which may be the problem. As the pump wears, it may not build up enough pressure to trip the pressure switch.

Just a theory.

Spyderweb

@jhofmann, since I’m committed to replacing pump, I’m going with that theory.  Pump probably is 11 years old, so it’s likely tired.

Willhound

And most of them have an internal pressure switch so only fix is to change entire pump.

Stodge

There is a slim chance that the diaphragm is shot.  If that happens there there will never be enough pressure developed to flip the pressure switch off.

I think the rebuild kits runs about $35.

Spyderweb

Found identical pump online and ordered it last night ($99 + free shipping).  Also found old papers that came with boat that PO replaced pump in May 2014.  So, not as old as I thought, but from what I read, these types of pumps aren't all that bullet proof. 

JimGuy341

Does it run continuously on shore power too?  Had a similar issue, pump wouldn't stop running when on battery.  Hooked up to shore power, ran normal.  Turned out the house battery wasn't holding a charge so the pump wasn't getting the voltage needed to build enough pressure to turn off.

Spyderweb

Yes, tried that too.  Had shore power hooked up and battery charger on for the extra boost, but made no difference.

LaRea

5 years?  Replace and count yourself lucky.

LaRea

And thus is illustrated, once again, the value of keeping maintenance records.

raybo3

LaRea said:

And thus is illustrated, once again, the value of keeping maintenance records.

I have every single maintenance record at my disposal. I can make a phone call and get what I did 10 years ago when I first bought my boat. VERY IMPORTANT!!!!

MarkB

Spyderweb said:

Tried rapping the pump all over.  No luck.  Couldn’t figure out how to get into pressure switch.

i do wonder, if pump won't shut off, wouldn’t pressure really build up, and you’d have tremendous pressure in system?  Is there some kind of relief valve, like on the water heater? 

Anyway, I give up.  Will order pump this weekend.  Appears straight forward to install.  Only concern is if inlet and outlet fittings will be the same.  This one has the blue lever you pull and it releases the fitting.

Pump will build up pressure to a point (called the dead head) and then it won't be able to pump against the pressure anymore, so flow stops.  Pump just then spins without moving water. The real issue is the water in the pump casing gets hot because it isn't going anywhere, and it could get hot to the pump where it generates steam ... and that's when you'll have a problem.

Dream_Inn

MarkB said:

Spyderweb said:

Tried rapping the pump all over.  No luck.  Couldn’t figure out how to get into pressure switch.

i do wonder, if pump won't shut off, wouldn’t pressure really build up, and you’d have tremendous pressure in system?  Is there some kind of relief valve, like on the water heater? 

Anyway, I give up.  Will order pump this weekend.  Appears straight forward to install.  Only concern is if inlet and outlet fittings will be the same.  This one has the blue lever you pull and it releases the fitting.

Pump will build up pressure to a point (called the dead head) and then it won't be able to pump against the pressure anymore, so flow stops.  Pump just then spins without moving water. The real issue is the water in the pump casing gets hot because it isn't going anywhere, and it could get hot to the pump where it generates steam ... and that's when you'll have a problem.

Yes, I have a friend whose 270 caught on fire because his broker left the water pump on.  Boat was basically sold, but paperwork was being done next day.  Talk about bad timing for him!

Spyderweb

Installed new pump today.  Pretty straight forward.  And accessible. Filled the water tank full.  Turned on power and pump took off.  Water out all faucets, no air whoosh out of any of them.  Turned all the faucets off and the pump just kept going and going.  Same as before.  No signs of leaks anywhere.  

Will it it keeps running if it’s sucking air?  If there’s a leak downstream of pump it should leak water.  I’m thinking if it’s upstream it would suck air but not sure if that would prevent it from shutting off.  The pre-filter that attaches right to the pump seems pretty loose.  You can swivel it around even when clamped in by the pump.  There doesn’t seem to be any gasket on the pump.  Should there be one on the filter end?

Ian

It should seal and not suck air as that wil stop it pressurizing too.

raybo3

Take the tubing off of the discharge side of the pump and push your hand on it hard and have someone else turn the pump on and see if it shuts off under pressure. My guess is you have a leak somewhere. 

DanD2

Could be a leak on the water tank side of the pump.

Spyderweb

@raybo3 took tubing off discharge side and had outlet totally plugged.  Not a drip.  Had pump turned on and it stayed on.  And think this would point to pressure switch.  It’s a brand new pump. Could anything else cause this problem?

@DanD2 have not found any leaks.  And based on above test, leaks or not, looks like it would keep on pumping.

Spyderweb

here is strainer that attaches to inlet side off pump.  Seems quite loose when clamped into pump.  There is no gasket/o-ring on either this part or the pump inlet.  Should there be?