Fresh water pump hammering, tripping breaker

[Driftwoods]

I put in a Shurflo fresh water pump last summer and it's worked flawlessly since. This week it started hammering a little, not too terrible but just noticeable. Yesterday, it began to trip the breaker. Not consistently, just two times.

I'm at a loss as to what could have happened. The inlet filter is clear, no changes to the system have been made (electrical or plumbing). I thought air might have gotten in the system but I don't know how to bleed that out.

Any ideas?

[neptunesjester]

If it is tripping the breaker, that doesnt sound like air in the line. I've used these pumps for years and know from experience that they can run dry for a long time without damage.

What I have had happen is scale buildup in the head create a pinhole in the membrane between the head and motor. This caused pressurized water against the front bearings and flooded the motor casing. The pump would run but would get hot, behave strangely, and trip the breaker.

The leak had no exterior signs, no drips, nothing. I only discovered it when I unmounted the pump to check the head and felt water slosh inside the motor.

Later,
NJ

[atoll]

sounds like time to replace the pump!
have found they start to get noisey when the ossilating bearing is worn or starting to sieze,which makes the motor work harder,then can cause it to trip.

ive had problems getting them to seal properly after being stripped down,and generally just replace with new,have found they tend to fail after 2 years with constant use, and 1year if shower is in use a lot as well.

[sailorboy1]

Is it pumping any water? If it is dry running the vanes heat up and start sticking till the breaker will pop. Have you checked the suction connections? Have you tried a different tank? Try blowing the suction line out to be sure it isn't clogged.

[HappyMdRSailor]

Originally Posted by neptunesjester

If it is tripping the breaker, that doesnt sound like air in the line. I've used these pumps for years and know from experience that they can run dry for a long time without damage.

What I have had happen is scale buildup in the head create a pinhole in the membrane between the head and motor. This caused pressurized water against the front bearings and flooded the motor casing. The pump would run but would get hot, behave strangely, and trip the breaker.

The leak had no exterior signs, no drips, nothing. I only discovered it when I unmounted the pump to check the head and felt water slosh inside the motor.

Later,
NJ

Originally Posted by atoll

sounds like time to replace the pump!
have found they start to get noisey when the ossilating bearing is worn or starting to sieze,which makes the motor work harder,then can cause it to trip.

ive had problems getting them to seal properly after being stripped down,and generally just replace with new,have found they tend to fail after 2 years with constant use, and 1year if shower is in use a lot as well.

I've had similar experiences to both...

Amazon has a ton of pumps at competitive prices...

[Driftwoods]

It does still pump water quite nicely, barely noticeable difference when the stuttering starts. I'm wondering if maybe there's a vacuum in the water heater.

[HappyMdRSailor]

Originally Posted by Driftwoods

It does still pump water quite nicely, barely noticeable difference when the stuttering starts. I'm wondering if maybe there's a vacuum in the water heater.

Darnit Drifty... Are you going to make us think now???

If it was just a hammering problem... I would think air, and bleed it out... Check upstream and downstream for leaks... taps too... But your trippin' now too... points to a pump going south...

How close is your breaker value to pump draw specs???

If you're on the cusp, added load of hammering putting you over?

[Stu Jackson]

Originally Posted by Driftwoods

It does still pump water quite nicely, barely noticeable difference when the stuttering starts. I'm wondering if maybe there's a vacuum in the water heater.

The pump pumps through (into) the heater, so you couldn't have a vacuum there.

Follow the good advice here. Either tear it down and find the issue, or just get a new one.

[Driftwoods]

A little update as it seems I may have figured this out ....

I was looking under the galley sink at the pump trying to psych myself up for all the stuff I'd have to remove to gain sufficient access to the pump so as to limit my cursing when I noticed the PEX tubing had somehow gotten pressed over at a angle that gave the tube a really hard turn. I figured that was not right no matter what so took the 2 seconds needed to put it back into a straighter run.

Inspiration hit me and I tried the water again and it ran smoother without ever tripping the breaker. Still hammering a bit, not like the smooth flow I had at first install.

Consequently, I looked back under the sink and noticed the tube that allows us to pull the faucet sprayer out seemed awfully tightly turned too. There is a weight on it that pulls the tube back in as you remount it onto the sink and I think the tube may have relaxed enough since its install that the weight was pulling it into a much harder turn than it originally was. I straightened that out and now it runs almost as smoothly as the day it was installed. Haven't tripped a breaker in a couple of weeks.

I can only guess that the 2 tight turns that had somehow gotten into the system allowed pressure to build quickly and release quickly as water tried to move through them, thus the hammering. All that hammering was more than the wiring/breaker was designed to withstand so the breaker tripping happened.

Whatever it was, it's fixed now. Thanks for all the feedback and ideas!