Instant Water Heater Disconnect Under Sink
- Thread starter TPW
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kwired
Electron manager
- Location
- NE Nebraska
Use two pull out disconnects that are commonly used for air conditioning equipment disconnects. Will probably be about the least costly thing you can use and they are fairly reliable.
cadpoint
Senior Member
- Location
- Durham, NC
They are not rated that high @ 40 Amps... I looked (ok, my thought as well)
kwired
Electron manager
- Location
- NE Nebraska
They are not rated that high @ 40 Amps... I looked (ok, my thought as well)
There are some out there, but the pullout switch is much less cost.
cadpoint
Senior Member
- Location
- Durham, NC
I'll give you that thought, but would the home owner know to reach under a cabinet verses running to a panel? Not to be argumentive but a pull out is more of an exterior
app. and doesn't lend itself as an application per say/by design gezz do we have to consider this an application, but it is a viable answer! I concour...
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kwired
Electron manager
- Location
- NE Nebraska
Why would the HO need to to know to reach under the cabinet. The disconnect is required for servicing the equipment it serves. Breaker lock is acceptable for this install but the OP wanted a local disconnect.
Pullout is in 3R enclosure but is not limited to outdoor use. It is not designed for any specific application it is simply a disconnect that has a pullout design for operation. It is just as suitable as any other switch as long as its current rating is not exceeded.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I would install wp disconnects without a thought other than is there room for them. Two units that take 40 amps??? Dang what a waste.
kwired
Electron manager
- Location
- NE Nebraska
From what I understand it is instantaneous water heater. Requires two 40 amp circuits. They take a lot of power because there is no storage and the unit has to heat the water as it is used. They do not use any power however if no water is used.
I still think they cost more in maintenance than a tank style heater costs to operate even though it is wasting some heat. Tank style are not wasting heat in winter months - the heat is being lost to your home and lessening the demand on your heating system.
That is a little off base, many houses have the water heater in the garage that is not conditioned space. Tank water heaters are less efficient in a couple of ways. First they heat water and have to run to maintain their heat 24-7-365. Second, if gas, they loose heat up the flue pipe, unless you are using a high efficiency water heater (very pricey). Putting an "in demand" water heater at the point of use will also save the heat and water lost in the pipe run from the tanked type heater to the fixture, once you turn off the faucet the water in the pipe will just cool down.
The big problem with "on demand" water heaters is water quality and high cost of installation. If you have poor water quality, such as high calcium levels, your tankless will plug up internally very quickly. They need to be flushed out monthly, many of them come with bypass ports for connecting to just for this reason. I believe they use vinegar to clean them out, but I am not sure about that.
kwired
Electron manager
- Location
- NE Nebraska
I don't know where you live but around here if you put water lines in a garage it better be conditioned space or you will have frozen water lines at some time. Most water heaters around here are in basements or mechanical rooms within the main part of the structure.
All gas heating appliances lose some heat out the flue that is why you will never see a 100% efficient gas appliance.
Heat lost from a hot water tank is really only a total loss of energy when you are trying to cool the space the tank is located at. Otherwise it is simply adding heat to a space and reqiring less demand from the heating system. The colder the average climate is where you live the more you really need to think about this before rushing into the decision of having a tankless water heater. Total annual enerrgy cost plus cost of equipment over its average life span may not make any sense to use the tankless. There are a lot of green people out there that will spend a dollar to save a dime.
Robert Hutcherson
Member
- Location
- Pembroke Pines,Florida
Have you considered two 50amp240volt straight blade receptacles, with cord and caps on the appliance? I answered this without skimming applicable code section. This would take up less room.
How about any clearance issues with the disconnects being under a sink in a cabinet?
stew
Senior Member
- Location
- federal way,washington
I have the same questuion as TPW how about 110.26a ?
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
IMO, 110.26 does not apply. Some will argue this but they are wrong...:grin: Just kidding. I don't see a disconnect as requiring examination, adjustments, maintenance etc. esp. if no ocpd is installed.
mivey
Senior Member
You can also use a heat pump water heater which will cool the space around it thus also reducing your A/C cost.
stew
Senior Member
- Location
- federal way,washington
if 110.26 doesnt apply then why are we required to provide clearance to one of these when used with an a/c unit?
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