TOPIC: Double tapped 15 and 20 amp breakers-

If you have no other electrical issues but you find one double tapped 15 or 20 amp breaker do you recommend an electrician (call it out as a defect)?

Depends,

Is it the low voltage transformer? Some call this out some do not.

Yes a double tap is a defective condition and needs to be addressed by a qualified electrician.

Verbiage:
(Double tapping), two or more wires on a single pole breaker can add to the load of the affected circuit causing a possible overload and tripping breakers, or result in loose connections and overheating of the breaker or connections.

Or
DOUBLE TAPmultiple conductors listed for single conductors noted at breaker(s). Recommend a qualified professional review the panel manufacturers instructions for proper attachment.

Thank you David!

Dumb question but are you sure it was a double tap?  Brand of breaker / panel?  Sometimes it is hard to see the connection point on the breaker.  Double taps are easy repairs in most circumstances with a pigtail.  In my state, since it is a licensed trade, I am required to recommend a licensed electrician.

My sister in Richmond, Va complained that an inspector cited her double tapped breaker. The buyer wanted an electrician, and the electrician told my sister it was a Sq D panel and had a breaker specifically designed for double tapping. I've been looking into it since, and looking for it on my inspections. Maybe the type of breaker is designed for double tapping but care should be taken that it doesn't cause an overload? Any time I see double tapping, or any wiring issue, I always recommend an electrician make the repairs. We don't know the client's or homeowner's capabilities. I always assume my client is 96 yrs old and legally blind, so she can't repair anything!

Sq. D breakers generally allow double tapping per the manufacturer's instructions.  Thus, if such a connection is made it poses no hazard but may result in the breaker tripping if the combined load exceeds the breaker's rating.  Just like any other circuit, a tripping breaker is due to an overloaded or faulted circuit, but that is a different problem than whether the breaker has one or two wires connected to it.  With respect to low voltage transformers in the panel (mentioned above) I always write that as a defect.