Still battling water pump issue

[philh]

Dealer fixed the issue with water coming in from the onboard tank. According to their report, filter was blocked. BS, the winterizing suction tube worked fine and the shut off valve is now in the system with hose clamps... so that was at least removed by the dealer.

Now, I've got water hammer so bad that something is likely to break. Found no o-ring to seal the filter to the pump, added an o-ring. Did not change the behavior.

This may be an important observation, while the water hammer is undergoing, the LED lights are flickering.

It's 150 miles one way to the dealer, and I'm more than a little frustrated.

[opnspaces]

philh wrote:

Yes, they are right next to each other.

Pressure switch is kind of what I'm leaning towards. Wondering if the dealer messed with the settings in a misguided diagnosis.

I may just buy a pump this weekend and stop. Learning about accumulators too, even if I do get this fixed, see value in adding one.

The pressure switch should be adjustable. I believe Shurflow has an hex (allen) bolt at the top of the pressure regulator. maybe give it a half or full turn one direction and see what happens. Check both a sink and the shower to see how the different pressure affects it.

[DFord]

I ran across a big accumulator for an RO system in a thrift store cheap and connected it into our water system. It stores about a gallon of water so the pump doesn't need cycle nearly as often. I was lucky to buy a variable speed pump from a tailgater at Quartzsite years ago and love it! Instead of running full tilt or not, it slows down gradually before stopping as the accumulator tank fills. I have to listen closely to hear our pump run. The variable speed pumps are more that twice as much as the standard pumps (unless you find a tailgater selling new ones).

[time2roll]

I agree that all these closed water systems should have at least a small accumulator. If spending money I would be getting a more expensive pump the regulates speed not just on/off.

[philh]

opnspaces wrote:
In thinking about where you said the led was flickering when the hammering was occurring. Is there a faucet close to the water pump switch? maybe try turning off the faucet and simultaneously flipping off the water pump switch. I'm thinking the flickering LED might be from the pump trying to still push water well beyond the shutoff pressure and causing the LED to blink while it's hammering.

Yes, they are right next to each other.

Pressure switch is kind of what I'm leaning towards. Wondering if the dealer messed with the settings in a misguided diagnosis.

I may just buy a pump this weekend and stop. Learning about accumulators too, even if I do get this fixed, see value in adding one.

[opnspaces]

In thinking about where you said the led was flickering when the hammering was occurring. Is there a faucet close to the water pump switch? maybe try turning off the faucet and simultaneously flipping off the water pump switch. I'm thinking the flickering LED might be from the pump trying to still push water well beyond the shutoff pressure and causing the LED to blink while it's hammering.

[philh]

wopachop wrote:
Could there be a water bubble stuck in the pump? Could loosen the pump screws and tilt and shake the pump while it runs maybe?

Or possibly a slight air leak on the intake side? Like when a straw has a crack and introduces air.

Good questions and that's why I replaced the missing o-ring. I don't see any air bubbles in the filter. So don't think air leak that's the issue. Air trapped in the pump, that's an interesting question.

[wopachop]

Could there be a water bubble stuck in the pump? Could loosen the pump screws and tilt and shake the pump while it runs maybe?

Or possibly a slight air leak on the intake side? Like when a straw has a crack and introduces air.

[philh]

This isn't a pipe rattling issue or vibration, this is a serious water hammer issue that will break something. Doesn't matter which faucet is run, the problem persists.

[opnspaces]

philh wrote:
Dealer fixed the issue with water coming in from the onboard tank. According to their report, filter was blocked. BS, the winterizing suction tube worked fine and the shut off valve is now in the system with hose clamps... so that was at least removed by the dealer.

Now, I've got water hammer so bad that something is likely to break. Found no o-ring to seal the filter to the pump, added an o-ring. Did not change the behavior.

This may be an important observation, while the water hammer is undergoing, the LED lights are flickering.

It's 150 miles one way to the dealer, and I'm more than a little frustrated.

When you say water hammer are you referring to the pump pulsation noise when it's running? Or are you referring to a hammer noise when you close the faucet and the pump stops?

If you're referring to the pump pulsations I would guess that the dealer inadvertently moved a PEX line against something. Maybe try turning on the outside shower so the pump runs but doesn't fill a holding tank. While the pump is running reach in around the pump and move the PEX lines to see if the noise changes. If you can silence or minimize the noise then use a piece of foam or Styrofoam to hold the lines in this position.

[maillemaker]

My LED lights also flicker when my water pump is on. I used to see the old incandescent dim slightly when the pump was on, but with the LED replacements they flicker. I suspect this is because of the cycling drop in voltage due to the pump - the electrical system has not been designed to provide even voltage to the light fixtures to keep the more-sensitive LED lights happy. I suspect future RVs will have to isolate the power to the pump somehow.

[DFord]

Another thought is there's supposed to a pocket of air in the water heater to allow expansion of the water as it's heated. Try completely draining the hot water tank and refilling it. That will renew the air pocket and should help with any water hammer.

If the pump is "hammering" while it's running, it's probably because the water lines to or from the pump are rattling against the walls of the wet compartment. See if you can reposition those lines to stop the noise. A pad of some sort might help between the wall and the water line at the point of contact.

[philh]

Pump did not hammer before dealer "fixed" the tank flow issue.

All the air had been previously purged using municipal water.

i have not tried multiple faucets open, but hot and cold together lessens the impact.

[YC_1]

New to you unit?
Did it always hammer?

This hammering is very common and there are kits to calm them down. They can make a great deal of noise in some installations.

Example of a cure

There are kits sold that come with a couple of hoses to make the intake and output lines flexible. If Pex is connected directly to a pump it can really machine gun the whole rv.

[DFord]

Rapid on/off cycles are normal when one faucet is partially opened. It should quit if you open the faucet all the way. A accumulator tank will soften the hammer of those on/off cycles.

RV Fresh Water System Accumulator Tank 305730001A
https://dan-marcrvparts.com/product/rv-fresh-water-system-accumulator-tank-305730001a/

or

DIY Water Accumulator
http://www.modmyrv.com/2009/06/10/rv-diy-water-accumulator

[shastagary]

sounds more like the pressure switch at the pump going on and off as the system comes up to pressure that would make the lights flicker.
have you opened all faucets and gotten all the air out of the system? that could cause the pump to cycle on and off rapidly as it gets up to pressure.