Newbie question - very loud sounds using water pump

[budh9534]

With the fresh water tank 3/4 full, I turn on the water pump (located under couch behind driver's seat), and it purrs like a kitten (can barely hear it running - almost have to touch it to know it is running).

Then when I open a faucet, whether it be the hot or cold faucet, it makes a very loud screeching noise and this continues after the air in the lines is bled out. Even if I try using a small amount of water flow, it is making a lot of noise continually even after any water hammer or filling of lines should have finished long ago. And a second or two after stopping water flow, the noise disappears.

And this noise seems to be coming from an area near the back of the water heater and sink area, well away from the water pump location.

Being a power plant operator and dealing with venting of pumps and piping and water hammer potential issues, this seems strange in that so much noise is resulting from flowing no more than 3 gpm through a faucet.

So what's causing this racket to occur?

[450Donn]

Not sure by reading a verbal deacription, but it sort of sounds like your getting air in the system. Possibly a bad check valve at the pump.

[Mudfrog]

Originally Posted by budh9534

With the fresh water tank 3/4 full, I turn on the water pump (located under couch behind driver's seat), and it purrs like a kitten (can barely hear it running - almost have to touch it to know it is running).

Then when I open a faucet, whether it be the hot or cold faucet, it makes a very loud screeching noise and this continues after the air in the lines is bled out. Even if I try using a small amount of water flow, it is making a lot of noise continually even after any water hammer or filling of lines should have finished long ago. And a second or two after stopping water flow, the noise disappears.

And this noise seems to be coming from an area near the back of the water heater and sink area, well away from the water pump location.

Being a power plant operator and dealing with venting of pumps and piping and water hammer potential issues, this seems strange in that so much noise is resulting from flowing no more than 3 gpm through a faucet.

So what's causing this racket to occur?

Reading your post, specifically the bolded part,,, it sounds like you might be thinking that the pump runs the whole time the switch is on. If like every system I've ever come across, the pump only runs when pressure drops enough to call for it. Examples, when first turned on to pressurize the lines and then afterwards, when a faucet is opened.

As far as the noise, you most likely will hear the pump when it's running. They are sometimes noisy but I've never heard one that was really obnoxious. I've never heard one making a screeching sound.

[Gary RVRoamer]

I'm not clear whether what you describe is normal operation or some problem.



The pump only runs briefly (seconds?) when turned on, until it build pressure to around 45 psi. Then it shuts off and becomes totally silent. Opening a faucet drops the pressure and causes the pump to turn on again, making noise as it rebuilds pressure.


There should be no air in the lines after running the water (opening a faucet) for a short time. Usually only 20 seconds or so, but some systems may take a minute or tow to clear out any accumulated air. Once that happens, no more air should enter unless the lines have been drained for some reason.

[Travis98146]

You may try purging all the water lines (kitchen sink, bathroom sink & toilet) one at a time as you may have air left in one of them.

[Old-Biscuit]

The check valve in the WH Tank HOT Outlet is failing/chattering because they are CHEAP junk.....plastic plunger/spring/o-ring assemble that gets clogged with calcium/scale and/or O-ring gets dislodged.


Why a Check Valve in HOT Out-cause RV MFGs are too cheap to install shutoff valve

Check valves are cheaper and can be installed prior to installation of WH Tank.




SIde note: 4 yrs NAVY and 25 yrs Control Operator/Power Plants for SCE
Welcome fellow Power plant operator!!!!

[budh9534]

Originally Posted by 450Donn

Not sure by reading a verbal deacription, but it sort of sounds like your getting air in the system. Possibly a bad check valve at the pump.

The water pump (Shurflo 2088-422-144, 2.8 gpm, 45 psi) presumably has an internal check valve to ensure "city water" hookup does not cause water to go backwards through the pump and fill your fresh water tank.

It appears to be working properly (preventing the backflow with city water connected but allowing forward flow when needed with the pump running and no city water connected).

[hohenwald48]

Originally Posted by budh9534

The water pump (Shurflo 2088-422-144, 2.8 gpm, 45 psi) presumably has an internal check valve to ensure "city water" hookup does not cause water to go backwards through the pump and fill your fresh water tank.

It appears to be working properly (preventing the backflow with city water connected but allowing forward flow when needed with the pump running and no city water connected).

The check valve Old-Biscuit is talking about is located on the water heater and normally comes into play when you winterize the water system so you don't have to put 6 gallons of antifreeze in the water heater. You might want to take a look at it. They do fail as O-B describes.

[Persistent]

Your description seems like something is seriously wrong. The screeching, loud hammering, and air in the water does not sound proper.

As posted above, the pump should stop altogether when it reaches full pressure. It should not be running even quietly. When you first fill your lines you should get air out of every faucet, toilet, etc. After that you should get no air. There may be a great deal of air from the hot water tank when you first fill it. There should be no more air after that.

It is not clear from your description whether you are getting air after initial filling of the system. Assuming that you are, there is an air leak in the suction side of the pump. It could be in the pump itself or the suction hose and fittings leading from the fresh tank to the pump.

There is at least one check valve on the output side of the pump. Check valves sometimes make a banging noise when they close. The pump turns on and off quickly to regulate the pressure. Every off cycle causes the check valve to close and could cause fast loud banging. If there is air mixed with the water, the valve may produce unpredictable banging.

Any hoses or pipes connected to the pump may vibrate against near by objects.

I wish you good luck and happy trails ahead!

[Old-Biscuit]

Originally Posted by Persistent

Your description seems like something is seriously wrong. The screeching, loud hammering, and air in the water does not sound proper.

As posted above, the pump should stop altogether when it reaches full pressure. It should not be running even quietly. When you first fill your lines you should get air out of every faucet, toilet, etc. After that you should get no air. There may be a great deal of air from the hot water tank when you first fill it. There should be no more air after that.

It is not clear from your description whether you are getting air after initial filling of the system. Assuming that you are, there is an air leak in the suction side of the pump. It could be in the pump itself or the suction hose and fittings leading from the fresh tank to the pump.

There is at least one check valve on the output side of the pump. Check valves sometimes make a banging noise when they close. The pump turns on and off quickly to regulate the pressure. Every off cycle causes the check valve to close and could cause fast loud banging. If there is air mixed with the water, the valve may produce unpredictable banging.

Any hoses or pipes connected to the pump may vibrate against near by objects.

I wish you good luck and happy trails ahead!

Unless installed by Previous owner there are NO check valves on Pump Discharge side of pump
Pump has an INTERNAL check valve which is just a diaphragm on the suction side of drive diaphragms
Only other check valve woul be internal of city water inlet....which closes/stays closed when pump is used AND a check valve in Water Heater Tank HOT Out


WH Tank HOT out check valve WILL chatter when they are clogged up/failing


Pump check valve (diaphragm) will just allow plumbing system to leak down until pump pressure switch closes/pump runs to bring system pressure back up
Or allow bcakflow thru pump when using city water and cause fresh water tank to overflow
Pump check valve is QUIET cause it is just a diaphrgam


OP needs to check if that NOISE is coming from WATER HEATER

[Mudfrog]

The check valve at the water heater tank may be the culprit, especially since the OP stated that there is noise is near to the water heater. Only thing that throws me is the fact that he stated that the noise occurs during cold water usage as well.

[budh9534]

Some new data.

City water hooked up, all hot and cold water lines filled and vented. Turned on water pump and opened cold faucets. Then slowly closed city water valve. When pressure dropped to near 30 psi, then the loud noises returned, which do seem like they are coming from near the sink and hot water heater area and not near the pump.

No noise at all if on city water.

[Persistent]

Originally Posted by Old-Biscuit

Unless installed by Previous owner there are NO check valves on Pump Discharge side of pump
Pump has an INTERNAL check valve which is just a diaphragm on the suction side of drive diaphragms
Only other check valve woul be internal of city water inlet....which closes/stays closed when pump is used AND a check valve in Water Heater Tank HOT Out


WH Tank HOT out check valve WILL chatter when they are clogged up/failing


Pump check valve (diaphragm) will just allow plumbing system to leak down until pump pressure switch closes/pump runs to bring system pressure back up
Or allow bcakflow thru pump when using city water and cause fresh water tank to overflow
Pump check valve is QUIET cause it is just a diaphrgam


OP needs to check if that NOISE is coming from WATER HEATER

I agree. Water heater is more likely the issue.

However, my pump has been noisy at times. The noise is associated with the pump. It usually dissipates after a couple of days of use. Others have reported the same behavior.

It also gets louder when the fresh tank get lower.

[budh9534]

One other piece of information - the check valve at the water heater outlet was replaced 8 days ago. That was the reason I was getting no water at the hot faucets (unless I “put it on bypass”).

The water heater now works great, despite “looking its age”.