# Dishwasher connection and wiring, oh boy!



## Bigplanz (Apr 10, 2009)

The dishwasher died and has to be replaced. So, I disconnected the water supply, the drain and pulled it out of the counter. Oh boy. The romex the installed used was 14 gauge and was hardwired into the back of the machine. At the breaker box, of course, nothing was labeled, so I turned breakers off until I found the right one. This involved turning a breaker off, going upstairs and holding a pen tester to the wire, When the tester didn't chirp, I knew I had the right one.

Since the romex was too short to really get to the connection, I cut the cable as close to the machine as possible. No problem. Out comes the machine.

Now, here's the problem. While testing breakers, I discovered that the circuit the dishwasher is on is 20A and this circuit is also the one the washing machine is on. So, I have 14 gauge wire on a 20A circuit, and if memory serves, a washer is supposed to be on its own circuit anyway, I couldn't find a code requirement in the 2005 NEC for this, so I may be mistaken. What I definitely need to do is pull the 14 gauge wire and replace it with 12, from the junction box to the dishwasher, and make sure that the rest of that circuit has 12 gauge all the way back to the breaker.

What started as a simple pull the dishwasher and replace it is now a rewiring job, for which I will have to get a permit, and which may fail anyway due to the jackleg wiring job some idiot did down in my basement when they ran power to the dishwasher and installed an outdoor receptacle. Yes, that's a problem too. While tracing the dishwasher circuit down I discovered it (the outdoor receptacle) is also wired with 14 gauge wire and is on a 20A circuit.:furious:

I suppose I could just replace the breakers with a 15A, and I may just do that for the outdoor circuit, but the washer and dishwasher really need a 20A circuit. 

This is a cautionary tale. I seem to find stuff like this in every house I have ever had. There are lots of effed up wiring jobs out there folks. 

Q: should I hard wire the dishwasher or install a receptacle and wire the machine with an appropriate cord and plug? The code says you can do either, but I am looking for some pros and cons here from those knowledgeable on this subject. 

Also, what's your collective experience with inspectors in re: existing conditions unrelated to what you pulled a permit for? Down in my basement the jackleg who did the wiring for the dishwasher also strung romex along the underside of floor joists and along the exterior of a drywall stairwell. None of this is code compliant. I am concerned the inspector will fail my whole effing house and I'll have to rewire the whole basement. 

Thanks for any advice.


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## AllanJ (Nov 24, 2007)

I am not saying you should do it but if you hard wire the dishwasher with a brand new 12 gauge Romex strung correctly nonstop to the panel without telling anybody and without pulling a permit, then chances are nobody will ever notice.


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## gregzoll (Dec 25, 2006)

Actually the dishwasher can be on the same circuit as the garbage disposal. Personally, I would use BX or armored from the dw to the jb under the counter for the disposall. What is the specs on the plate for the dw.


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## Daniel Holzman (Mar 10, 2009)

One other item you may want to check. In my town, the dishwasher needs to be switched, with a visible switch above the counter. I guess the theory is that if someone is working on the dishwasher, they should be able to have visible evidence that the circuit is off. I don't know why throwing the breaker is insufficient, but whatever. So you may want to install the dishwasher on a 20A circuit switched through a 20A switch, as long as you have to do all the work anyway.

As for a permit, in my town you don't need a permit for rework of an existing circuit, which sounds like that is what you are doing. Of course, if you ask, you are probably going to need a permit, but if the rules allow, and you don't ask, well maybe no problem?


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## gregzoll (Dec 25, 2006)

Sounds odd that your town requires a switch above the counter for the dishwasher. What is to keep someone from flipping it, not knowing what it does. This is why with my disposal I placed the switch right inside the sink base, so in order to run it, you have to open the door. Daniel, what does your town state about using a GFI for the disposal & dw, and would they consider that as the switch to shut the devices off.


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## rjniles (Feb 5, 2007)

I would install a receptacle in the junction box (15 amp receptacle is fine on the 20 amp circuit) and install an appliance cord on the DW. This meets the requirement for a disconnect and at least in my jurisdiction, this does not require a permit. The other 20 amp circuit with 14 gauge wire, I would change the breaker to 15 amp untill you do an overall correction.


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## stubborn1 (Oct 24, 2008)

Until you call your inspector and explain the situation, you are going to be speculating on an answer. 

When I remodeled my kitchen a few months back, I pulled a new 20A circuit for both the DW and disposer to a duplex receptacle under the sink. Top half was switched for a disposer switch above the counter. Both the DW and disposer were connected to the receptable via the proper appliance cord. In my area, the inspector allows the receptacle/appliance cord connection as a disconnect in lieu of a switch above the counter, but I had to call and find out first before starting the work.


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## electures (Dec 22, 2009)

How old is the house? Check the installation instructions to see if it requires a seperate circuit. Chances are if it is an energy saver model it will. My guess is that when the first DW was installed it was a builders grade POS and only required a 15A circuit. When it was replaced an energy saver was installed, but nobody bothered to replace the branch circuit with a 20A. The next question you are wondering is how a 20A DW can save money over a 15A. The energy saver has an electric heating coil in the bottom which heats the water above what the WH does. The energy savings comes when the water heater tempature is lowered because it doesn't need to be set high enough to sterilize the dishes. That is what the heating coil in the bottom does. A seperate 20A circuit is needed because of the heating coil. The WH temp only needs to be hot enough for taking a shower.


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## rjniles (Feb 5, 2007)

electures said:


> How old is the house? Check the installation instructions to see if it requires a seperate circuit. Chances are if it is an energy saver model it will. My guess is that when the first DW was installed it was a builders grade POS and only required a 15A circuit. When it was replaced an energy saver was installed, but nobody bothered to replace the branch circuit with a 20A. The next question you are wondering is how a 20A DW can save money over a 15A. The energy saver has an electric heating coil in the bottom which heats the water above what the WH does. The energy savings comes when the water heater tempature is lowered because it doesn't need to be set high enough to sterilize the dishes. That is what the heating coil in the bottom does. A seperate 20A circuit is needed because of the heating coil. The WH temp only needs to be hot enough for taking a shower.


I have never seen a DW that does not have a heating coil. Most people never have their water heater set high enough for a DW(140 degrees). In fact that would be a very dangerous temperature and is well above the 125 recommendations.


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## electures (Dec 22, 2009)

rjniles said:


> I have never seen a DW that does not have a heating coil. Most people never have their water heater set high enough for a DW(140 degrees). In fact that would be a very dangerous temperature and is well above the 125 recommendations.


I have been wiring houses for 35 years. The builders mostly use the non energy savers because they are cheap. Hence we install #14/2. If it is a custom home, we install #12/2 figuring on an energy saver D/W.


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## hardwareman (Oct 9, 2010)

electures said:


> I have been wiring houses for 35 years. The builders mostly use the non energy savers because they are cheap. Hence we install #14/2. If it is a custom home, we install #12/2 figuring on an energy saver D/W.


it does not matter one bit whether a dishwasher is energy star rated or not, or whether they are cheap pieces of crap. they still draw the same amount of amperage as any high end energy saver with all the bells and whistles.


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## hardwareman (Oct 9, 2010)

electures said:


> The next question you are wondering is how a 20A DW can save money over a 15A. The energy saver has an electric heating coil in the bottom which heats the water above what the WH does.


dishwashers do not get energy star ratings because they have a heating element in them . Dishwashers as far back as 1960 have heating elements in them, they get their energy star rating from the water usage, less hot water means less energy is consumed .


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## electures (Dec 22, 2009)

hardwareman said:


> it does not matter one bit whether a dishwasher is* energy star rated* or not, or whether they are cheap pieces of crap. they still draw the same amount of amperage as any high end energy saver with all the bells and whistles.


I'm sorry, but where did I say anything about energy star ratings? I stated "energy saver" And the "energy saver" that I am referring to *did not* have heating coils. Try re-reading my post.


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## electures (Dec 22, 2009)

hardwareman said:


> it does not matter one bit whether a dishwasher is energy star rated or not, or whether they are cheap pieces of crap. *they still draw the same amount of amperage* as any high end energy saver with all the bells and whistles.


Oh, and the units without the heating elements draw less current which was why we could run #14/2 to them. Remember, no coil = less current.:no:


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## Jim Port (Sep 21, 2007)

From a random pick of a DW on Sears website








This ENERGY STAR® qualified Kenmore appliance uses up to 20% less energy than dishwashers without the ENERGY STAR® rating.

I also looked at an Energy Star high end Bosch unit. It only required a 15 amp circuit.


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## rjniles (Feb 5, 2007)

electures said:


> Oh, and the units without the heating elements draw less current which was why we could run #14/2 to them. Remember, no coil = less current.:no:


I am sorry but all DW's have a heating coil. It heats the water if under temp and it also used for the drying cycle.


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## gregzoll (Dec 25, 2006)

electures said:


> I have been wiring houses for 35 years. The builders mostly use the non energy savers because they are cheap. Hence we install #14/2. If it is a custom home, we install #12/2 figuring on an energy saver D/W.


I also have never seen a dishwasher without a heating coil to help dry. Every dw on the market for consumers has a heating coil in it.


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## vvzz (Apr 25, 2011)

Bigplanz said:


> This involved turning a breaker off, going upstairs and holding a pen tester to the wire, When the tester didn't chirp, I knew I had the right one.


You might want to invest in one of those circuit breaker finders. You can get a decent one for less than 50 bucks. My panel is poorly labeled and having one of those has proved indispensable.


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## electures (Dec 22, 2009)

rjniles said:


> I am sorry but all DW's have a heating coil. It heats the water if under temp and it also used for the drying cycle.


Not going back 35 years. Am I the only electrician who remembers this. If you look at my first post I ask how old the house is. I suspect that the house was constructed mid 70's to early 80's. If that is the case then quite possibly the first DW was a "builders grade" which means it didn't have the heating coil. The EC ran 14/2 to the DW. Back then only the "energy saver" DW's had the pre-heat coil and required a seperate 20A circuit. They are no longer called "energy savers" but instead are "energy star" and all have pre-heaters and some require seperate 20A circuits. None of this means anything. I was trying to explain why I thought the original circuit was 15A. Bottom line read the installation instructions to find out the electrical requirements.


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