Wiring 2.5 gal water heater

[rd65]

I will be adding a small, under sink water heater in the shop. I am looking at a 2.5 gallon Bosch that plugs into a 120 outlet. My question is can I run 12ga romex in emt conduit? I am out of thhn but have plenty of 12ga romex. The plan is to run the romex only in conduit from panel to attic and from attic to outlet. Conduit can be 1/2" or 3/4", whatever is needed for these short 5' & 7' runs. If conduit cannot be run in conduit can I remove the outer sheath for the distance that it is in the conduit? Panel is in the left corner of pic, sink will be in the right front corner.

 

[Terry D]

The Code allows it in conduit to protect it from physical damage. Doesn't really give a maximum length. I will say, they more bends you have , the harder it is going to get it in there. I personally would use THWN

 

[wyliesdiesels]

No prohibition on NM-b in pipe indoors but its a pain in the ***

 

[sparky 1971]

It won't be too bad if you are only going through a 5' and a 7' piece of emt. If it were me, I would get the emt stubbed up at both ends first. Then take the romex in the attic and push the ends down through the pipe. It will be a ***** trying to drag the whole length of romex through one of the stubs. Put a fitting on the ends of the pipe in the attic so it won't rub through the romex. There is a fitting made that is like a combination emt/romex connector, but I usually use a set screw coupling and call it a day.

Edit: I just made the picture big and looked at it. If it were me, I would run a 3/4 emt out of the panel and on the bottom of the ceiling all the way over to where the water heater will be. Make sure the romex doesn't have any twists in it and pull it through. That is just me being a 300 pound fat guy that absolutely hates going into attics.

 

[rd65]

There will be no bends in the conduit (besides the S bend out of the panel to flush w/ wall) , just a straight shot up the wall to attic space. Would 1/2" conduit be ok for 12/2 wire? Heater paperwork says 12 amps but I will be using 20 amp circuit since that is what I have and for wiggle room on that outlet.

 

[sparky 1971]

There will be no bends in the conduit (besides the S bend out of the panel to flush w/ wall) , just a straight shot up the wall to attic space. Would 1/2" conduit be ok for 12/2 wire? Heater paperwork says 12 amps but I will be using 20 amp circuit since that is what I have and for wiggle room on that outlet.

1/2" will be fine for the sleeves.

 

[Norcal]

OK to sleeve the NM cable, not OK to strip the sheathing off the NM cable in the EMT.

 

[BillK]

RD,
Cant help you with the wiring but . . . . . . .

What are your plans for the sink ? Just washing hands ? If so you might be happy with the 2.5 gal heater. Anything more than that and you should consider a "real" water heater. You can get them in 12 gal that still run on 110. When I first moved into my present business location they had one of those small under the sink heaters like you are looking at. It was pretty much useless in my opinion. I took it out and installed a 12gal one. That has done pretty much anything I have ever needed.

 

[Copymutt]

Wire lube is your friend.

 

[yatg]

Put a fitting on the ends of the pipe in the attic so it won't rub through the romex. There is a fitting made that is like a combination emt/romex connector, but I usually use a set screw coupling and call it a day.

There's also a plastic bushing that slips over the open end of the EMT.

 

[u2slow]

I run this size water heater under my kitchen sink. Tucks away nicely on raised shelf. Saves a lot of water since there's almost zero wait to get hot.

I will say, use a good quality receptacle, or hardwire. 2 years ago I redid the countertop and discovered the std cheapo one I used had become heat dis-coloured and partly deformed.

 

[rd65]

It will only be for hand washing. Part of the plan for the heater under the sink is my hope that heat radiating from heater will help keep temps up enough that I wont have to worry about pipes freezing. They will come up through the floor at the cabinet. I will have a hose bib coming out the front of the shop as well. I live north of Seattle and the winter temps may get into the upper teens from time to time and I don't keep the heat on in the shop. The plumbing will be exposed to the cabinet area. If needed I can run a light bulb to help with temp. The cabinet will be insulated and will be using pex for lines.

 

[rd65]

OK to sleeve the NM cable, not OK to strip the sheathing off the NM cable in the EMT.

Ok, good to know. Thanks.

 

[Norcal]

A straight conduit should not be that hard to get NM in but add any bends and it will be more difficult.

 

[sparky 1971]

There's also a plastic bushing that slips over the open end of the EMT.

I forgot about those. I actually have a package on my truck....somewhere. By the time I remember them, it's too late and the romex is in the pipe with a coupling acting as a bushing.

 

[nadogail]

I have the same Bosch Water under the sinks in two garages. I ran dedicated circuits of 12-2 NMB to a receptacle next to the heaters and plugged the flex cord of the heater into the GFCI receptacles.

 

[46MGTC]

I have the same Bosch Water under the sinks in two garages. I ran dedicated circuits of 12-2 NMB to a receptacle next to the heaters and plugged the flex cord of the heater into the GFCI receptacles.

I did the same thing with my Bosch water heater about 10 years. Still working fine with no problems.

 

[rd65]

Finished it up about a month ago. Heater is putting off enough heat to keep the cabinet at 42* or above, even with our current cold spell (lows in the low to mid 20s). Havent run out of hot water during any of my useage so far. 2.5 Gallon Bosch unit. Yes, it did take over 5 years to get this all finished up. I was not looking forward to running the line from the stopping point near the house to the water service line, everything was in the way; power, gas, cable, and phone. AND I had to find the service line. Small pressure washer with a Turbo nozzle for ditching work was great. Messy, but easier than hand digging. Previous owner had put down lots of 1-1/2" rock as driveway material for getting into the back yard.

 

[Plump]

Nicely done. I have the same water heater (an upgrade from an old one that did it's duty well) and it's PERFECT for washing hands and some dishes. Very quickly reheats at that size so it's never an issue as far as size goes.

 

[jpcjguy]

It will only be for hand washing. Part of the plan for the heater under the sink is my hope that heat radiating from heater will help keep temps up enough that I wont have to worry about pipes freezing. They will come up through the floor at the cabinet. I will have a hose bib coming out the front of the shop as well. I live north of Seattle and the winter temps may get into the upper teens from time to time and I don't keep the heat on in the shop. The plumbing will be exposed to the cabinet area. If needed I can run a light bulb to help with temp. The cabinet will be insulated and will be using pex for lines.

I did the Bosch 7 gallon - there is no heat radiating from the unit that I can tell, they are insulated well - so I would not count on that.
I found that the 7 gallon is a nice compromise between 2.5 and 12....

 

[rd65]

I did the Bosch 7 gallon - there is no heat radiating from the unit that I can tell, they are insulated well - so I would not count on that.
I found that the 7 gallon is a nice compromise between 2.5 and 12....

It does put off some heat. I hung a digital thermostat in cabinet and it has not gotten below 42*, while the shop has been as low as 36* during our recent cold snap. Outdoor lows here have been mid 20's for the last week or so.

 

[jpcjguy]

It does put off some heat. I hung a digital thermostat in cabinet and it has not gotten below 42*, while the shop has been as low as 36* during our recent cold snap. Outdoor lows here have been mid 20's for the last week or so.

Fair enough - mine is not in a cabinet so it is open to the shop. Was just my observation from being around it (checking fittings, etc.) with my hands....