>>>> "William" == William Donzelli <aw288 at osfn.org> writes:
>>> 
 > NO! NO! NO!  BAD ADVICE!
>  >> One should never replace a breaker with a higher rated one  
 unless
 > they are sure the wiring can accomodate the
increased amperage.  A
> 15A breaker requires 14 guage wire.  A 20A breaker requires 12
> guage wire.  Putting a 20A breaker on 14 guage wire is flirting
> with disaster. 
  William> I would not call it "flirting with disaster", but it is not
  William> a good idea. The chances of a fire breaking out under this
  William> circumstance is damn small, but it is there.
  William> On the flip side, many homes are wired with 12 anyway, so
  William> the replacement breakers are OK.
 So I've heard.  I've seen it rarely if ever.
 Note that 20 amp requires 12 gauge copper.  In homes of the right
 (wrong?) age, you may find 12 gauge aluminum -- that's legal only for
 15 amps.  If you want aluminum and 20 amps, you'll need 10 gauge --
 plus components rated for aluminum wire, which are generally somewhere
 between rare and nonexistent, and often very expensive. 
 
   And this is a huge problem, potentially much more dangerous than
 undergauge wire (as in more likely to cause problems; maybe not likely
 to cause more problems).
   I lived in a duplex with clad aluminum wiring and copper-rated
 breakers, fixtures, and wire nuts.  I discovered this when replacing
 my porch light fixture.  I touched the earth ground lead, and got the
 poopie shocked out of me.  I thought I must have brushed a "hot" wire,
 and got more poopie shocked out of me.  The house was carrying 55V on
 the earth ground.
     Doc