my mom said that he was only in 1 episode where he walked through the scene, said a line, and that was it. and then my uncle told me that he was never in an episode they only talked about him the first few years.

He was a regular member of the cast and was on for the first 2 seasons played by two different actors.

Chuck appeared in 8 episodes, he was played by Gavin O'Herlihy in 6 episodes, and Randolph Roberts in 2 second season episodes:

#1- "All the Way"
#3- "Richie's Cup Runneth Over"
#4- "Guess Who's Coming to Visit"
#6- "The Deadly Dares"
#8- "The Skin Game"
#10- "Give the Band a Hand"

#17- "Richie Moves Out"
#27- "Guess Who's Coming to Christmas"

Chuck definitely didn't get a lot of lines, but he did have a few.

and, in the "Love and the Happy Days" episode of Love American Style that started it all, Chuck was played by Rick Carrott.