Just because I'm curious and want to take a stab at it-

... some kind of grounding issue? Is it a 60 cycle hum (pretty low pitched buzz) or something higher?

Not that I know anything about this, except that in some equipment such a hum can be cured by hooking up a simple chassis ground. So is your house properly grounded?

Just guessing and surmising.

This is occurring at my daughter's house, so to be certain I will have to ask her about the buzz. As I remember, it is not a really low buzz, but it is not really high either. If I had to classify it as high or low, I would say it is on the lower side. I will try to confirm that with her.

The house was built in early 2013, and I would hope it is grounded properly.

A friend had the idea that it might be a speaker that is in the stove (for the timer buzzer) that is being affected by the ground loop.

I am wondering if a ground loop hum eliminator would help.

I really appreciate your interest in trying to figure this out.

So the stove is plugged into a regular receptacle? Next time the buzzing occurs, unplug the stove and see if the buzzing stops.

The stove is plugged into a 110 volt outlet.

I failed to state in the original post that we did unplug the stove and the buzzing does stop. In fact, the stove is now hooked up to a surge protector that sits on the counter so the stove can be easily disconnected whenever the hot tub is running, which is fairly frequently.

This post was edited by BJS360 on Mon, Mar 3, 14 at 21:46

" ... only happens when the neighbor's hot tub is running ... " implies that for whatever reason (code for "I don't know why") the pump or heater in your neighbor's hot tub emits a radio frequency electromagnetic pulse that is picked up by the wiring in your house, and to which something in the stove (a circuit board in the timer or temp controls, perhaps?) is sensitive.

In other words, some piece of electronics in his system is behaving like a radio transmitter, and some piece in your daughter's is responding to it like a radio receiver. Her house's wiring is the antenna. But since it stops when you plug your stove into your neighbor's system I still suspect a ground- either one, although I suspect the hot tub, since everything was fine until it went in.

Of course, that's just a wild guess with a lot of neat words. I have no idea why such a thing should be so. But my next comment would wonder if the hot tub parts are properly grounded and shielded.

Bus and others here will figure it out- I'm just an occasional lurker and they're exceptionally qualified. I'm probably just muddying the waters. But it is an intriguing puzzle and I'm really curious to know how it works out.

Thank you for your post, marknmt. I found it very interesting. I will pass this information on to my daughter. Her neighbor seems quite interested in solving it, and I know he will be interested also.

I certainly am learning a lot in trying to solve this puzzle!

Just a wild guess that a plug-in noise filter might help. It is what I would try. Determine if a 5 amp or 10 amp unit is needed. No guarantees from me as to effectiveness.
If neighbor cooperates, get all the info from the hot tub and contact the manufacturer.

Here is a link that might be useful: Filter

"get all the info from the hot tub and contact the manufacturer."

Yup.

Good luck with this. You'll get it sooner or later. When you do, would you please let the board know what you learned? Thanks.

Bus, could a relay with marginal insulation cause something like this? I'm thinking of a thermostat. I suppose there's a dozen things that could cause it, and that comes to mind because there's just not a lot going on in a hot tub, is there?

This post was edited by marknmt on Mon, Mar 3, 14 at 22:27

Would a plug in noise filter provide more noise filtering capability than the UPS unit and surges could provide? How do I determine whether a 5 or 10 amp plug in noise filter is needed?

The neighbor bought the tub second hand and had to work on it a bit to get the unit working.

Thanks for all your suggestions! I will post back if we make any progress.

UPS's only coincidentally provide any filtering (in fact many are NOISY in their own right). A surge protector provides NONE.

Is there a possibility that the hot tub has a poor ground? If so, isn't there a risk there?

Again, just fumbling in the dark.

"How do I determine whether a 5 or 10 amp plug in noise filter is needed? "
I assumed that the person knew how to do this. Or had some imagination. Here is a clue: READ THE NAMEPLATE/specification plate on the stove.

Thanks for your help, bus_driver. I will check that.

There was a guy on my welding forum using a high frequency tig welder that would raise havoc with his and his neighbor's power and the cable TV. After several months the POCO found a bad neutral connection at the transformer and all the problems went away. I am not smart enough to tell you why and how the weirdness happens, just relaying the story. Some hot tubs have high frequency ozone generators. Just sayin.

This post was edited by joefixit2 on Tue, Mar 4, 14 at 21:06

We tried the plug-in noise filter yesterday. The buzz is still there.
We will see about getting the hot tub information from the neighbor. I gather that the neighbor believes that the problem is with my daughter's stove. He has suggested that she call Whirlpool to see if they can resolve the problem.
Meanwhile, is there anything else that can be tried at our end? Should we consider calling an electrician?
Thanks again for all the suggestions.

I can only guess without prior experience with the proplem what is going on. Although the tub is almost certainly 240v,maybe only one phase is causing this. Temporarly connect the range via extension cord to another outlet that is on the opposite phase. If that takes care of it and you are knowledgable about home wireing you will know the procedure to switch the outlet onto the other phase. Otherwise,I beg you to let a pro do it and not ask someone how because although it's simple,there are some serious possible pitfalls.
If you opt to hire a pro to diagnose it ,I would at least talk to a tv/electronics repairman. Idealy you find one who is also an amateur radio operator. You might even look for an operator as the first step because he may refer you to one in the daughter's nieghborhood.
I am almost as curious to hear what it is as what happened to flight 370.

The power to that residence is single phase. 120 volts uses one "pole", 240 volts uses 2 "poles". The conductors used for 240 single phase are often also called "lines", as Line 1 and Line 2.
I do agree with trying the 120 volt circuit from the opposite pole of the 240 volt service. Costs nothing to try. But since both poles of the 120/240 originate from one transformer winding, it is not highly likely to correct the problem. Signals on one pole will be on the other.
An experienced observer on the scene could look to see if both residences are served by the same transformer. If not the same transformer, then the interference is more likely to be transmitted through the air.

This post was edited by bus_driver on Mon, Mar 17, 14 at 12:18

You guys are probably hooked up to the same transformer and the extra amp draw is causing it. I would call the power company and ask them to check the transformer.

"The power to that residence is single phase. 120 volts uses one pole, 240 volts uses 2 poles.
I do agree with trying the opposite pole of the 240 volt service. Costs nothing to try. But since both poles of the 240 originate from one transformer winding, it is not highly likely to correct the problem.
A more experienced observer could look to see if both residences are served by the same transformer. If not the same transformer, then the interference is more likely to be transmitted through the air. "

Thank you for that little tutorial bus_driver,someone might find it helpful some day. Judging by how prolific you are in posting,sometimes multiple times in a single thread as you did in this one. So that people don't get the notion you are only counter-posting to other member's observations,please do something for us. Explain what your point is by saying " the power to that residence is single phase" AND "both poles of the 240 origionate from one transformer winding". It is this kind of advanced knowledge that alows even seasoned tradsmen to gain knowledge here on the GW discussions. Please don't think this is a who can squirt highest on the wall. To the contrary it is to advance knowledge or more acuratly in my case and a number of tradsmen who worked around me over the years, correct use in believeing inaccurate info.
I will keep mine simple and to the point,please do the same so that it is easy to understand. Here is how I explain it to those just begaining to study residential wiring.
Since house current is alternating current the actual direction that the electrons flow reverses direction 60 times per second (60 cycles). Put another way, the hot wire has a negative charge alternating with an equal positive charge, and the polarity of the hot wire reverses 60 times per second.
Now a quick explanation of 240 / 220 volt house current; Appliances which use straight 240 current (such as electric water heaters,hvac or hot tubs)

1. A black wire which is often known as a "hot" wire, which carries the current in to the fixture.
2. Another "hot" wire which may be blue, red or white (if it is white the code actually requires it to painted or otherwise marked one of the other colors, but often it is not) which also carries current in to the fixture.
3. A bare copper wire called the ground, the sole function of which is to enhance user safety.
   That's it, no neutral.
   Now, if you were paying attention, you are probably wondering "If there isn't a neutral wire then how is the circuit completed?" The answer is that when one hot wire is negative, the other is positive, so the two hot wires complete the circuit together because they are "out of phase". This is why 240 volt circuits connect to double pole breakers that are essentially two single pole breakers tied together. In the main panel, every other breaker is out of phase with the adjoining breakers. So, in essence 240 volt wiring is powered by 2 - 120 volt hot wires that are 180 degrees out of phase.

After I understand all I "think" I know about the above,we will climb the transformer pole out back while you explain how a single winding supplies 240 volt.
Thank you in advance,I'll set down and listen to you.

"Although the tub is almost certainly 240v,maybe only one phase is causing this. Temporarly connect the range via extension cord to another outlet that is on the opposite phase."

My purpose in the response to that post was to help keep others who may peruse this forum from being misinformed. Otherwise, the focus is on the mysterious noise problem.

Here is a link that might be useful: Article

This post was edited by bus_driver on Mon, Mar 17, 14 at 13:22

In other words bus driver,you don't know and the best you can do is post a link that starts right off by saying "There is an assumed understanding of basic DC theory, Ohms Law (V=IR), the Power Law (P=VI) and Kirchhoff’s Voltage and Current Laws." The man on the street doesn't have nor need understanding of those unless he is in a profession where DC theory is required to complete his tasks.
If you actually had basic understanding of those requisites that artical would take on a whole new meaning. Otherwise when it mentions the difference between DC and AC,it flys right over your head.
There is no misinformation in what I said to the op and even if there was,it's abundantly clear you are not the one to point it out. I was very carful to avoid getting the op in over his head and clearly said so. It's unnessary so all you are doing is muddying the water by sniping and counter posting.

"Anger is a wind which blows out the lamp of the mind".

Robert Green Ingersoll

A wild guess, what if the installers bonded the hot tub to the gas pipe? Do you know if the gas pipe is bonded to ground? Did you check if the outlet feeding the stove is properly grounded?

Also, did you try running the stove on the UPS on battery power (i.e. with the UPS unplugged from the wall), does it still buzz?

This post was edited by Valdemar on Mon, Mar 24, 14 at 21:48

Update:

The EMC reported that they detected stray voltage when they tested earlier this week.

Next week they will investigate more when both homeowners are there so they have access to both homes and yards.

Both homes are on the same transformer

I do not think the UPS was tried on battery power. The UPS unit belonged to her neighbor, and he brought it over to try.

I'm looking forward to learning how this plays out. Thanks for your follow up.

Please update - this is fascinating. Sounds like something very unsafe or illegal with this hot tub and I would not live with that situation myself.

Every electrical device has a requirement not to cause electrical interferance, this is clearly not meeting that.

Been a member here a while and used to post a lot. I do manage to find the time to catch up on reading once in a while and got a bit distressed reading this post.

As a professional, nothing says amateur to me as much as another supposedly knowledgeable individual talking about "phases" in a single phase residential electrical setting.

You don't need to know how it works theory-wise as a homeowner, only that a 120/240 volt electric supply consists of the output of a single coil set in a transformer that is center tapped. Potential between both ends is 240 volts and either end to the center tap (which is grounded and called a neutral) is 120 volts. The transformer is supplied by two wires, one of which is grounded, again, single phase. There are ways to get multiple phases out of this arrangement but none of them accomplish it by using a residential panel exclusively . Other equipment is required.

Having been in some part or another of the electrical field for around 45 years, and having come to the realization many years ago that I don't know it all and learn something new almost every day, I'm relieved to know there are some like klem1 holding down the fort who evidently do know it all.

I have over the years picked up a lot of useful information from many people here and include Bus among a few with a lifetime of experience I wish I had at my disposal. And, I suspect Bus knew a lot more about the ins and out of the electrical field, long before klem1 was ever a twinkle in someones eye, than he ever will.

Of course, before my post gets jumped on I want to make its purpose clear - it's too bad some of use have such fragile egos we need to jump on folks who devote a lot of time trying to help others.