Existing 2 pole 15 amp breaker,14-2 wire, red, black & bare ground. Poles labeled kitchen lights and bath lights & fan. The fan has an outlet fan and a second small fan that includes a heater coil. The fan box carries a lebel 14.2 amps. The breaker pole sides seem to be misslabeled as I measure the current, the with fans running I get like 11.2 amps with the black wire in the loop ammeter in the breaker box and 0.3 amps measuring the red wire. If I switch on a kitchen light, the amps through the black wire increases and the amps through the red wire stays the same. I thought the box is wired wrong, but as I read about breakers, I think I just need to replace the 15 amp double pole with a 20 amp double pole as the fan and kitchen lights is forever blowing the 15 amp breaker.

NO! If the wire is #14 you CANNOT simply install a larger (20A) breaker. 15A is the largest you can put on #14 for general use circuits.

So let me get this straight, you have bath vent/heater/light, right? Check the specs with the manufacturer, most of these require a 20 amp breaker and #12 wire all by themselves. BTW starting amps for that fan will kick much higher than running amps.

The wire is No. 12, but the double pole breaker is only 15 amps. I measure amperage only on the black wire in the breaker box. Seems to me that this is just 1 circuit for both the kitchen and the bath with its lights and vent fan heater. I understand the need for the fan, light, heater fan to be on one 20 amp circuit, but not sure how to segregate one circuit with just a red, black and bare ground wire used. I must run a second 12-2 and substitute 2 20- amp or 1-20 and 1-15 for the existing double pole 15.

I would suspect that the original fan was a simple fan-only (draws less than 15amps) unit that has been replaced with a fan/heater (draws 15 or more amps) unit. With a red wire in the circuit I would also look for a second switch.

In one post you said 14-2, but you describe a wire which has 3 conductors, so it's 14-3.
Then in another post you say it's 12.. Are you sure of the wire size?

Hey Norton,

About the breaker, are you trying to describe a "Mini breaker" - A doubled handed handle that spans both breakers so that if one breaker trips, both go using only one slot on the panel or two individual breakers with fused handles so that if one goes they both go (2 Slots) - One feeding a black conductor and one feeding a red conductor?

Let's get the cables defined properly for you.

14/2 (max 15 amps) will contain a Black ungrounded (Hot) conductor and a White grounded (Neutral) conductor, the bare ground wire is not counted.

14/3 (max 15 amp) contains a Black conductor, a Red conductor which are both ungrounded or hot conductors. A White conductor, grounded conductor (Neutral) and a bare ground conductor (also not counted).

If you have a 14/3 (max 15 amp) or 12/3 (max 20 amp) cable then you might well be looking at a multi-wire circuit. In this case it would be a 15 Amp Feed from one breaker to the kitchen lights and a 15 amp feed from another breaker to the bathroom circuit. With Neutral as a shared conductor between the two circuits. If you are absolutely certain the cable is a 12/3 cable then you can upgrade the breakers to 20 amp each.

Please take some pictures of the wiring in the Main Service panel and at the bathroom and kitchen junction boxes.