Second question- exchanging 15A breaker for 20A

[borgster]

On one wall of kitchen in new house, two outlets. They have their own, 15A circuit. Have a Microwave (wife said it's too big, but she asked for a bigger microwave for Christmas- just got what she asked for) that is rated at 12A. When in operation it keeps tripping the circuit. Never had a problem in the old house. Microwave is a year old and seems to be working fine. I wonder if the breaker is in need of replacement. (house is 20 years old and all seems to be original in everything from siding to electrical). Question- since i would often like to have Microwave and another item operating at same time (food processor, blender, etc) can i simply replace with a 20A breaker so that the circuit will have more room? What do i need to check to make sure that this will be ok, not a hazard or should i leave as 15A.

[aphares]

Being a new house the circuit in the kitchen should have been a 20amp to begin with, unless you gust meant it is new to you, and just moved in.
If the breaker is a 15amp then first we need to determine what size wire is attached to the breaker, Two way's of knowing is to check the outside sheathing on the cable, It will have print on it, Or use a wire gauge in the panel to determine from 12awg/14awg.
If it is 14awg then 15 amp is the best you can do, On the other hand if it is 12awg then 20amp is possible.
You said the microwave never had this problem in old house; it very well could be that the old house had a 20amp circuit in the kitchen.
You asked if the breaker was going bad. With the microwave rated at 12amp, and the circuit at 15amp this only allows you a 3amp give, and if you was too check, Shut off the breaker, I bet your find more than just this outlet on the circuit. Thus giving you the other 3amps, Breaker good.
If it cannot be a 20amp, most possible it cannot, then running a new circuit is the best option from here.

[borgster]

Yes- i meant new to me- house is 20 years.

I need to check the circuit breaker- i think you're right that theres very little room (12A vs. 15)and there's probably something else on that circuit. Thanks for the tip about the wires. I will check and replace accordingly/as needed.