Bidet Causing Lights to Flicker

[SAS]

I installed a bidet toilet seat a few weeks ago. Initially I plugged it into an existing bathroom GFCI protected outlet. That worked just fine, but it required an extension cord on the floor for 6 feet or so, and my wife did not like the way that looked. This weekend I added an outlet near the toilet. Because this is on a different wall, and there is an unfinished attic behind that wall, I used a different circuit - the same one as the bathroom lights. Now when the water heater in the bidet seat comes on, the bathroom lights flicker. It doesn't matter what bulbs I use.

Clearly I will have to rewire that outlet to a different circuit. Ideally I would run a new line to the basement where the panel is, but I'm sure I can tap into a different circuit that will avoid the flickering (like the one it was originally plugged into). My question is less about how to solve the problem than about why it is happening. There are other lights on the same circuit, but those do not flicker. All of the bulbs in question are dimmable LED's, but I tried an incandescent bulb in the bathroom fixture, and it also flickered. Why is it that only that fixture has a problem? I can understand how the current fluctuation generated by the bidet seat could cause a problem, but wouldn't the same problem occur on all light fixtures on that circuit? Is there something in the wiring of the fixture itself that is causing only that fixture to be affected?

 

[Reach4]

My question is less about how to solve the problem than about why it is happening. There are other lights on the same circuit, but those do not flicker. All of the bulbs in question are dimmable LED's, but I tried an incandescent bulb in the bathroom fixture, and it also flickered. Why is it that only that fixture has a problem?

Odd. I suspect a marginal/loose connection.

 

[Sponsor]

 

[SAS]

Odd. I suspect a marginal/loose connection.

It would have to be at the fixture itself, since I know that the connection at the junction box where I added the circuit is good. Also, the fixture has 3 separate lights about 3 feet apart from one another. Could the gauge wire used to connect them be a factor? Would a smaller gauge wire result in more voltage fluctuation?

 

[WorthFlorida]

You may not have to change to a different circuit. Find all the outlets and switches on that circuit and the amperage of the circuit breaker. It’s no guaranty but lights will dim because there are a lot of crappy connections through outlets and switches from the circuit breaker. You didn’t say how old the wiring is. CT has a lot of old homes without an electrical upgrade.

Start with the outlets and replace them with an external back wire type outlet or pigtail the connection to the existing outlet. You want to eliminate the sidewire connection and if the wires going in are on one screw and the wires leading out to the next outlet are on the other screw, that little side tab carry all the current can cause a voltage drop. If the wires are pushed in holes on the back of the outlet, eliminate that type of connect. They are spring loaded and not much contact area to carry the current. Theses are only sized for 14 gauge wire. 12 gauge wire is too large.

With the back wire type outlet and switches, you place two wires in the clamp on each side of the same screw. Also, these outlets are more robust. The cheap 99cent outlets just don’t cut it. Be sure the outlet is the clamp type for back wire.

https://www.leviton.com/en/products/tbr15-w

 

[Jadnashua]

What is the wattage of the bidet?

FWIW, LED bulbs are much more susceptible to show effects of voltage change than an incandescent bulb...their on/off cycling time is much shorter...the incandescent takes time to warm up and then cool off, relatively speaking.

 

[SAS]

What is the wattage of the bidet?
FWIW, LED bulbs are much more susceptible to show effects of voltage change than an incandescent bulb...their on/off cycling time is much shorter...the incandescent takes time to warm up and then cool off, relatively speaking.

It's not the bulbs, because I tried replacing them with low wattage incandescents, and it made no difference. The bidet pulls 600 watts.

 

[SAS]

You may not have to change to a different circuit. Find all the outlets and switches on that circuit and the amperage of the circuit breaker. It’s no guaranty but lights will dim because there are a lot of crappy connections through outlets and switches from the circuit breaker. You didn’t say how old the wiring is. CT has a lot of old homes without an electrical upgrade.

Start with the outlets and replace them with an external back wire type outlet or pigtail the connection to the existing outlet. You want to eliminate the sidewire connection and if the wires going in are on one screw and the wires leading out to the next outlet are on the other screw, that little side tab carry all the current can cause a voltage drop. If the wires are pushed in holes on the back of the outlet, eliminate that type of connect. They are spring loaded and not much contact area to carry the current. Theses are only sized for 14 gauge wire. 12 gauge wire is too large.

With the back wire type outlet and switches, you place two wires in the clamp on each side of the same screw. Also, these outlets are more robust. The cheap 99cent outlets just don’t cut it. Be sure the outlet is the clamp type for back wire.

https://www.leviton.com/en/products/tbr15-w

I think you may be on to something here. I discovered that the problem also occurs at a lamp plugged into another outlet on this circuit. The ceiling lights are not affected, so my guess is that they are at the beginning of the circuit and the problem exists downstream from there in one of the outlets. It's easy enough to pigtail those 3 or 4 outlets. It doesn't cost anything and it certainly won't hurt. Hopefully it will solve the problem, otherwise I'll tap into a different circuit for the bidet outlet.

 

[SAS]

It's not the outlets, since I replace them all. This circuit is clearly overloaded, however. There are 7 wall outlets in the bedroom and sitting room, plus the dining room lights (directly below the bedroom), the bedroom ceiling lights and the bathroom lights. I added the bidet seat to that circuit. So I'll move the bidet seat, but do I need to move some of that off of a single 15 amp circuit? We've always had a problem where the bathroom lights dim when the computer printer is turned on or starts printing. I'm surprised the breaker hasn't tripped, and I'm starting to wonder if the breaker is faulty as well.

 

[Jadnashua]

If a device is used at higher current, things can get warm. That can cause the spring tension at the breaker to weaken. that can lead to a higher temperature, and make it worse.

Take the breaker out. See how easy it comes out. It should have some tension. With it out, take a close look at the bus bar to make sure it isn't corroded.

Then, make sure that the screws holding the bus bar to the main breaker are tight.

Current code requires a bathroom circuit to be 20A, and not be used outside of that bathroom as I understand it. They got away with more lenient installs years ago.

The main lines coming into the panel may be a little loose.

If you don't have experience working inside of a power panel, you should think twice...it can kill you. A load like the bidet or laser printer should not cause the lights to dim if all of the connections are tight and clean. I have my laser printer on a UPS. When it needs to heat up, I can tell the thing drops the line voltage because I can hear the UPS kick in, but no lights dim.

 

[Bcarlson78248]

All printers are not created equal, and some laser printers draw quite a bit more power than others. Having a 600 watt bidet on the same circuit as a laser printer is not a good idea because you never know when both will be drawing power. Technically a 15 amp circuit may be enough, but you are very likely to see a voltage drop if they both kick in at the same time, and it sound like you have lights that are sensitive to that drop.

Code requires a dedicated 20 amp bathroom circuit with GFCI, but I don't think that means you can't install a 2nd 20 amp GFCI circuit to run the bidet.

Bruce

 

[WorthFlorida]

What happens when a 1500 watt hair dryer is plugged in?

 

[SAS]

So, leaving the bidet seat aside, the lights have always dimmed in that bathroom when the printer starts up or begins printing. And unplugging the printer, the lights will still rhythmically dim when the bidet seat water heater is running. So the combination of the two isn't the issue. I've eliminated the outlets as a cause, and I just finished replacing the breaker. Nothing has changed. I do wonder if there is a bad connection somewhere in the circuit, but I've discovered that this circuit also controls the dining room chandelier! The circuits in the attic are nearly impossible to trace, so there could easily be a bad connection in one of the ceiling fixtures or in a random junction box in the attic.

I will move the bidet seat to a different circuit, and since it's my wife's printer she never complains about the bathroom lights dimming whenever the printer is in use.

 

[WorthFlorida]

Have you changed the wall switch? Check the light fixture connections? And my other question above, hair dryer?

 

[SAS]

Have you changed the wall switch? Check the light fixture connections? And my other question above, hair dryer?

The existing outlets in the bathroom are not on the same circuit as the lights, so a hair dryer has never been an issue. I replaced the wall switch about a year ago when I put in a timer for the exhaust fan. The problem existed before and after changing the switch. Also, the problem happens on a table lamp plugged into an outlet outside of the bathroom.

But about the hair dryer ... If I plug it in where the printer is plugged in, it does cause a slight dimming, but much less than the printer. So maybe the printer is its own problem. And the bidet seat doesn't dim the lights the way the others do; it causes a pulsating sensation in the lights. Other sites I've checked have reported that same problem with bidet toilet seats, but no one has explained exactly what it is.

 

[Jadnashua]

At a nominal 120vac supply, a 1500W hair dryer is 12.5A. Some laser printers, especially older ones, have a big power hit when you start them up the first time to print while it heats up the components. Newer ones are less susceptible to that, but it still can happen.

But, the initial peak with a LP along with a hair dryer probably won't trip a 20A breaker. If both were running for a long time, it might after a delay. Breakers trip fast with a short, but are somewhat slow to trip for a load that is at or close to their design limit, or, even if it exceeds its limit, if it is a short duration.

There's almost certainly a (single, or more) loose or corroded connection somewhere in the path that's causing dimming.

 

[SAS]

Thanks, everyone, for all of the advice. I moved the outlet to a different circuit. I had access in the attic to a 20 amp circuit that had only the washing machine on it. The owner's manual for the washing machine only requires a 15 amp circuit and only recommends that it be a separate circuit, so I'm comfortable that I am not in any danger of overloading the circuit. I'm going to check out that laser printer, since it is old and makes odd noises. It may be drawing a lot more current than it should. I'll check how much current it's drawing, and if it's excessive I may try to "tune it" or toss it.