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I'd like to connect a timer to my new instant hot water dispenser. The installation instructions mention not to use an extension cord, but I'd like to make the timer accessible under the cabinet so I can adjust it.

My plan had been to run a short heavy duty extension cord from behind the dishwasher to under the sink with a timer in between. Is there anything wrong with this?

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Frankly, it's probably not worth it. The tiny amount of electricity saved would be easily surpassed by the cost of a timer. – longneck Dec 10 '13 at 20:29
@longneck thanks, but I wasn't necessarily looking for advice on the economics. It actually costs about $40/yr to run at temperature. – glenviewjeff Dec 10 '13 at 21:41
An extension cord is not NEC approved for "permanent installations". As a homeowner you might not be bound to abide by the NEC, but if a fire resulted, your insurance company might find you negligent for creating an unsafe situation -- especially when the instructions for the device say not to use it with an extension cord. – Johnny Dec 10 '13 at 23:42
You might not save as much energy as you think you will since the water will cool while the timer is off and you'll have to heat it up again when you turn it back on. If you want to save energy and only want hot water for your morning coffee, an electric kettle that you fill yourself would be more energy efficient. – Johnny Dec 10 '13 at 23:49
Most timers aren't designed to take the load a heating element would need. You'll probably have to hardwire this with the timer turning on/off a relay on a separate circuit set up for the heater. – DA01 Dec 12 '13 at 8:06
up vote 0 down vote accepted

You need to determine the maximum current (amperage) your water dispenser will draw, then verify that both the extension cord and the timer can each handle that current as as sustained load.

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Don't you mean max amperage? – Ethereal Dec 16 '13 at 16:09
I had considered that in my originally but chose watts since most appliances only list wattage and standard (US) wall outlets are all at a fixed 115 voltage. Your assertion, however, is more correct especially when considering non-US, or higher amperage outlets. – virtualxtc Dec 16 '13 at 19:18
edited -- decided to take your advice. – virtualxtc Dec 16 '13 at 19:23

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