Whistling sound, Norcold N600

[baraff]

>>>I know this really belongs in the RV Appliance section, but I am hoping my question will get more views and potential answers here first. Mods, please move in a day or two if you need to.<<<


Our Norcold N600 fridge makes an occasional whistling sound which is something new. I have not heard it do this before. Currently we are camped at a State Park in Ohio, winding up a 3 week trip. As far as leveling goes, we are 1º off, front to rear and side to side, according to my Ridgid Leveling app, which corresponds to my bubble levelers, more or less.
This fridge is at least 17 years old, and has never given us any problems. I did replace the burner assembly about 4 years ago after I made the mistake of blowing compressed air through the orifice and totally fubaring the jet. We are on electric hookup now, not using gas. Other than that it has been trouble-free.
Is the whistling sound something to be concerned with or normal operation I have just never noticed?
Still seems to be cooling at this time.

[MrMark52]

Where is the whistling coming from?

If it’s from the doors around the front of the unit - it could be air slipping past the door seals. Chilled air takes less volume than warm air and has less moisture in it.
Warm air, which races to get inside of your refrigerator and freezer when the doors are opened begins to chill and the water is removed when the doors are closed, creating a vacuum inside the fridge which can cause air to be drawn slowly past the door seals.

[Gary RVRoamer]

There is no air natural air movement in that fridge that is fast enough or high enough volume to whistle. Nor any natural chemical movement or action that whistles. Even the gas jet can't whistle - it's operating at about 0.5 psi. The standard N600 has no fan of its own. Have you added any fans, inside the box or behind at the cooling unit? In any case, it is not natural.


My bet is that the whistle is not in the fridge. What else is nearby, maybe under or adjacent to it?

[MrMark52]

Originally Posted by Gary RVRoamer

There is no air natural air movement in that fridge that is fast enough or high enough volume to whistle. Nor any natural chemical movement or action that whistles. Even the gas jet can't whistle - it's operating at about 0.5 psi. The standard N600 has no fan of its own. Have you added any fans, inside the box or behind at the cooling unit? In any case, it is not natural.


My bet is that the whistle is not in the fridge. What else is nearby, maybe under or adjacent to it?

With all due respect Gary, any time there is a pressure differential there is an opportunity for a “whistling” to occur. The intensity of the sound may not be as great the lower the differential, but it does happen.

And, there IS a natural movement of air from outside to inside of a refrigerator and/or freezer as the air inside of the compartments increases in density and decreases in volume. It’s why it’s harder to open a freezer or refrigerator door after having just opened and closed them.
I can hear air being drawn into our home freezer after every time we open and hold open the door for a minute or so, or, if it’s real humid. And it is also harder to open the freezer door after just opening and closing. If we wait a minute, it opens much easier.

An understanding of thermodynamics is helpful here.

OTH - IF the whistle stated by the OP continues after opening/closing the doors, then it’s highly unlikely the doors are the issue as generally the door seals either begin to seal better, or enough of the density/volume changes have occurred so as to minimize the pressure differential across whatever orifice (seal to frame contact) was causing the whistle.

Finally, I will agree that the whistle could be from something else in the area.

[Old-Biscuit]

Whistling????

When ----what have you just done when it whistles?

How long does the whistling last?

Does it sound like whistling is from front of fridge or back of fridge?

Any specific time of day/night the whistling occurs?


Does it play a tune..........

[Mudfrog]

Originally Posted by MrMark52

With all due respect Gary, any time there is a pressure differential there is an opportunity for a “whistling” to occur. The intensity of the sound may not be as great the lower the differential, but it does happen.

And, there IS a natural movement of air from outside to inside of a refrigerator and/or freezer as the air inside of the compartments increases in density and decreases in volume. It’s why it’s harder to open a freezer or refrigerator door after having just opened and closed them.
I can hear air being drawn into our home freezer after every time we open and hold open the door for a minute or so, or, if it’s real humid. And it is also harder to open the freezer door after just opening and closing. If we wait a minute, it opens much easier.

An understanding of thermodynamics is helpful here.

OTH - IF the whistle stated by the OP continues after opening/closing the doors, then it’s highly unlikely the doors are the issue as generally the door seals either begin to seal better, or enough of the density/volume changes have occurred so as to minimize the pressure differential across whatever orifice (seal to frame contact) was causing the whistle.

Finally, I will agree that the whistle could be from something else in the area.

Hard to believe that a pressure differential between outside and the interior is the cause of the OP's issue. The pressure difference would have to happen quick and ongoing for that to cause the whistling. On the bolded,, just don't see how that can be true since the equalization is going to occur pretty much the instant the door is opened. It's definitely not going to take a minute or so.

Since the OP stated this is happening while on shore power, then what has been suggested already, might be to check for a circulating fan(s) issue. I've never heard of it happening but I suppose it's possible something could be going on in the cooling unit.

[MrMark52]

I was going to respond with some points to ponder but this thread is going off- track of the OP’s thread (much of it due to my comments).

Will be happy to discuss separately with anyone who wishes.

Now we can return to our regularly scheduled program.

[baraff]

Originally Posted by Gary RVRoamer

There is no air natural air movement in that fridge that is fast enough or high enough volume to whistle. Nor any natural chemical movement or action that whistles. Even the gas jet can't whistle - it's operating at about 0.5 psi. The standard N600 has no fan of its own. Have you added any fans, inside the box or behind at the cooling unit? In any case, it is not natural.


My bet is that the whistle is not in the fridge. What else is nearby, maybe under or adjacent to it?

@Gary RVRoamer,
OP here. I did add interior fans that mount on the fins in the lower cabinet, a long time ago. However, I turned them off, thinking that might be the problem. It was not however, the whistling continued.
It is intermittent though. I am wondering if it's being caused by the boiler when the thermostat calls for cooling. And it is a recent development, we've owned this motorhome for 12 years and never heard it before this trip.
We are on an electric only site, using the onboard water pump, so it's not a water pressure noise from the plumbing. There's really nothing else nearby.
Temps in the cabinets have been steady, everything seems to work. I even checked in the access panel for the dreaded yellow powder, fortunately there was none.

Maybe I'm just being paranoid.

[MrMark52]

Where is the whistling coming from - front? back? From underneath? From around one or both doors?

[Fridge Defend]

Originally Posted by baraff

>>>I know this really belongs in the RV Appliance section, but I am hoping my question will get more views and potential answers here first. Mods, please move in a day or two if you need to.<<<


Our Norcold N600 fridge makes an occasional whistling sound which is something new. I have not heard it do this before. Currently we are camped at a State Park in Ohio, winding up a 3 week trip. As far as leveling goes, we are 1º off, front to rear and side to side, according to my Ridgid Leveling app, which corresponds to my bubble levelers, more or less.
This fridge is at least 17 years old, and has never given us any problems. I did replace the burner assembly about 4 years ago after I made the mistake of blowing compressed air through the orifice and totally fubaring the jet. We are on electric hookup now, not using gas. Other than that it has been trouble-free.
Is the whistling sound something to be concerned with or normal operation I have just never noticed?
Still seems to be cooling at this time.

I do not see any responses, but I will add to this thread.

I will assume that you turned off the fridge and the noise did stop?

Our Dometic, when we get into the freezer and shut the door, it will slowly push out the warm air from the freezer and whistle for a minute or so. But it is clear where the noise is coming from.

Norcold burners can make a lot of noise, we have a fix posted on our website. But, again, the fridge would have to be in the LP Gas mode for this to occur.

Hope this helps, Paul