Constant Humming and Spurting When Using City Water

gacfl · 08-24-2021, 05:26 AM

Very new to RVing. Just purchased a 2021 Sprinter 3590LFT.

I have it hooked up to city water on my property. It would hum whenever a faucet was turned on. About an hour after using our electric water heater, it started humming constantly and spurts when turning on any faucet. I turned off the water heater from the inside console (just to be safe) and switched to pump to stop the humming.

Air pockets maybe? Any advice would be greatly appreciated. Thanks!

Javi · 08-24-2021, 05:58 AM

Quote:

Originally Posted by gacfl

Very new to RVing. Just purchased a 2021 Sprinter 3590LFT.

I have it hooked up to city water on my property. It would hum whenever a faucet was turned on. About an hour after using our electric water heater, it started humming constantly and spurts when turning on any faucet. I turned off the water heater from the inside console (just to be safe) and switched to pump to stop the humming.

Air pockets maybe? Any advice would be greatly appreciated. Thanks!

First question.. do you have a pressure regulator inline. not the cheap nearly worthless restrictor but an actual regulator ?

Second question... are you sure the all of the valves in your convenience center or correctly positioned to use city water?

Third question... did you open each hot water faucet and bleed all the air out as you filled the water heater?

gacfl · 08-24-2021, 06:07 AM

1) Haven't hooked it up, but I have a Valterra.

2) Yeah, I have it set to City Water on both the outside valve and the inside console.

3) I did. I have the water heater off right now, and it still hums and spits with faucets off while City Water is on.

Javi · 08-24-2021, 06:15 AM

Quote:

Originally Posted by gacfl

1) Haven't hooked it up, but I have a Valterra.

2) Yeah, I have it set to City Water on both the outside valve and the inside console.

3) I did. I have the water heater off right now, and it still hums and spits with faucets off while City Water is on.

see pm for answer

**sourdough** · 08-24-2021, 08:24 AM

Quote:

Originally Posted by gacfl

1) Haven't hooked it up, but I have a Valterra.

2) Yeah, I have it set to City Water on both the outside valve and the inside console.

3) I did. I have the water heater off right now, and it still hums and spits with faucets off while City Water is on.

Hoping Javi got you squared away but I have to ask; WHAT is "spitting" with the city water on and faucets off"?

gacfl · 08-24-2021, 08:29 AM

Quote:

Originally Posted by sourdough

Hoping Javi got you squared away but I have to ask; WHAT is "spitting" with the city water on and faucets off"?

Sorry, the water from the faucets spit when on. When off, it just continues to hum.

**sourdough** · 08-24-2021, 09:01 AM

Did you get it fixed?

gacfl · 08-24-2021, 09:03 AM

Quote:

Originally Posted by sourdough

Did you get it fixed?

Not at the camper right now. I'll circle back if I find the solution. Thanks.

**flybouy** · 08-24-2021, 11:35 AM

The “hum when it’s off” is curios to me. The only way to make something (hum) is via movement causing vibration. And before you science nerds go saying I’m wrong because a resonance frequency can do that. The rest of you are now Googling “resonating frequency”.

Anyway, makes me wonder if the pressure relief valve on the WH is leaking or maybe a faucet is on with the water **** off at the shower head.

**JRTJH** · 08-24-2021, 12:10 PM

My "WAG" is that the water pump is turned on with city water connected, there's air in the lines and the pump is running (humming) while the city water can't compress the air in the lines enough to stop the pump from running (humming)...

Turn off the water pump to stop the humming, purge the faucets of all the air to stop the spitting and make sure the water heater is full with the proper air gap before turning it on. That should stop the problems and get you hot water to boot.....

dutchmensport · 08-24-2021, 02:45 PM

Quote:

Originally Posted by JRTJH

My "WAG" is that the water pump is turned on with city water connected, there's air in the lines and the pump is running (humming) while the city water can't compress the air in the lines enough to stop the pump from running (humming)...

Turn off the water pump to stop the humming, purge the faucets of all the air to stop the spitting and make sure the water heater is full with the proper air gap before turning it on. That should stop the problems and get you hot water to boot.....

Good call .... or ....???? the the water valves might be set on "winterize", and the pump is attempting to pump air from a hose in a bucket that is simply not there. Meanwhile, the city water running is actually running in the lines too. Air mixed with water, causes "spitting."

Make sure your on-board water pump is turned off and your winterizing valves are not set for "winterize".

Blackrock · 08-25-2021, 07:34 AM

This all should have been addressed at the dealership when you did your PDI. They should have had your RV plugged in to power and electric and demonstrated to you how to operate all water valves. They should also have had the water heater turned on also.

It takes a while to get all of the air purged from the piping plus a complete fill of the water heater. I just crack the hw and cw faucets and let them spurt and spit until all the air is purged. This can take a while after being winterized.

wiredgeorge · 08-25-2021, 07:40 AM

Quote:

Originally Posted by Blackrock

This all should have been addressed at the dealership when you did your PDI. They should have had your RV plugged in to power and electric and demonstrated to you how to operate all water valves. They should also have had the water heater turned on also.

It takes a while to get all of the air purged from the piping plus a complete fill of the water heater. I just crack the hw and cw faucets and let them spurt and spit until all the air is purged. This can take a while after being winterized.

Bob, I believe the OP has already had the thought that he should have done a thorough check prior to driving off the lot. New camper owners don't get this education on their first purchase and will likely be a bit more prudent checking things out on the second go round. It is part of the painful learning experience. After de-winterizing my camper this spring (we had a heavy freeze and I blew out the lines and added anti freeze to the p traps) it took a LONG time to purge the air from the lines. I didn't time it but I bet 15 minutes.

rlh1957 · 09-02-2021, 08:19 AM

You have air in your lines, possibly air pocket still in hot water heater.
Sometimes it take awhile to get the air out.

You said you have all valves set correct for city water use.
Is there a separate power switch for water pump?
Turn it off.

Turn off HW heater both gas & electric.

Open HW faucet and let it run till all spitting is gone. Go to each faucet and run till clear.

**JRTJH** · 09-02-2021, 08:41 AM

Quote:

Originally Posted by rlh1957

You have air in your lines, possibly air pocket still in hot water heater.
Sometimes it take awhile to get the air out.

You said you have all valves set correct for city water use.
Is there a separate power switch for water pump?
Turn it off.

Turn off HW heater both gas & electric.

Open HW faucet and let it run till all spitting is gone. Go to each faucet and run till clear.

Just to be clear, there is a required air pocket in both the Atwood and Suburban water heater. That air pocket should be maintained. If lost, there is no "expansion capacity" inside the tank and as water is heated, that expansion will cause the relief valve to "weep" and/or if that valve fails, deform the tank causing (in the Suburban tank) damage to the porcelain lining which will cause premature failure of the tank. In both brands, expansion can cause a problem if the air gap is not maintained......

Both owner's manuals have specific instructions on how to maintain the water heater air gap.

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