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Open Roads Forum  >  Tech Issues

 > Flojet Water Pump hammering

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PostRoadFarm

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Posted: 10/25/20 03:42pm Link  |  Quote  |  Print  |  Notify Moderator

Trying to figure out whats happening...have done all recommendations to remove air, etc. This is a Flojet 4325 brand new. one sink, one shower.

https://youtu.be/PlykWfHsGkc


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12th Man Fan

Flower Mound , Texas

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Posted: 10/25/20 04:04pm Link  |  Quote  |  Print  |  Notify Moderator

This is very common and usually doesn't have anything to do with air in the lines.

The pumps start vibrating when it is coming up to pressure and the pex pipe starts hitting the wooden walls.

There is a kit to add a soft hose between the pump and the rigid pex pipe will help some but I put pipe insulation everywhere the pipes were touching wood and I put a piece of thick rubber under the pump to reduce the noise.

Very quiet now.


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2oldman

NM

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Posted: 10/25/20 04:25pm Link  |  Quote  |  Print  |  Notify Moderator

How's your battery? I've not heard a sound like that before.

Old-Biscuit

Verde Valley

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Posted: 10/25/20 04:49pm Link  |  Quote  |  Print  |  Notify Moderator

WHEN is it doing that??
Low water demand
After closing faucet
All the time faucet is open

????


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PostRoadFarm

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Posted: 10/26/20 06:09am Link  |  Quote  |  Print  |  Notify Moderator

Happens when one or more faucets open and never stops until faucet is turned off- regardless of demand. Battery is full and does it even with generator. A tech got it to stop one time by opening/closing the valve from the tank to the pump about 5 times in a row...he said it was priming (though this unit says it does not need priming). He didn't check the shower though and as soon as it was turned on, the hammering started again. We tried holding the pex and made sure none (at least around the pump area) was touching anything but it didn't seem to be the cause. We had a similar set up in our Airstream (different pump manu.) and it never made a sound...

My first attempt to fix is the flexible/soft hoses and following pex to add dampeners where it touches anything...

I also read there is a pressure valve screw that can be adjusted but it isn't showing on the cut-sheet for our model

Thanks for all of your replies...

prichardson

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Posted: 10/26/20 07:40am Link  |  Quote  |  Print  |  Notify Moderator

How far are you opening the faucet? Does it do it with a faucet wide open? Sounds like the pump flow capacity is exceeding the rate of discharge from the faucet. That pump has a 4.5 GPM capacity and will definately short cycle when using the shower. Adding an accumulator will solve that problem.

* This post was edited 10/26/20 07:46am by prichardson *

mbopp

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Posted: 10/26/20 07:50am Link  |  Quote  |  Print  |  Notify Moderator

prichardson wrote:

How far are you opening the faucet? Does it do it with a faucet wide open? Sounds like the pump flow capacity is exceeding the rate of discharge from the faucet. That pump has a 4.5 GPM capacity and will definately short cycle when using the shower. Adding an accumulator will solve that problem.

Yes, I have a 2 gallon residential expansion tank. It stops the short cycling, holds enough for a few nightly potty runs w/o the pump, and as a bonus it cut down the annoying burst of hot water when taking a Navy shower.


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Marysdad

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Posted: 10/26/20 11:12am Link  |  Quote  |  Print  |  Notify Moderator

Adding an accumulator tank solved a similar issue for me.

Old-Biscuit

Verde Valley

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Posted: 10/27/20 01:04pm Link  |  Quote  |  Print  |  Notify Moderator

PostRoadFarm wrote:

Happens when one or more faucets open and never stops until faucet is turned off- regardless of demand. Battery is full and does it even with generator. A tech got it to stop one time by opening/closing the valve from the tank to the pump about 5 times in a row...he said it was priming (though this unit says it does not need priming). He didn't check the shower though and as soon as it was turned on, the hammering started again. We tried holding the pex and made sure none (at least around the pump area) was touching anything but it didn't seem to be the cause. We had a similar set up in our Airstream (different pump manu.) and it never made a sound...

My first attempt to fix is the flexible/soft hoses and following pex to add dampeners where it touches anything...

I also read there is a pressure valve screw that can be adjusted but it isn't showing on the cut-sheet for our model

Thanks for all of your replies...


Is the water flow from faucets pulsating also?

Pressure switch...factory pre-set for 40# shutoff
No adjustment screw

* This post was edited 10/27/20 01:14pm by Old-Biscuit *

doxiemom11

Victoria TX

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Posted: 10/27/20 01:22pm Link  |  Quote  |  Print  |  Notify Moderator

Our pump does that when we switch from fresh water tank to city water hookup or vice versa and forget to change the setting for the water system.

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