I decided to change some outlets around my home, my electrical knowledge is basic at best. I bought some 15 amp GFCI outlets as the replacements. The first outlets that I pulled out were 15 amp outlets, so good so far, I believe that they are "line" outlets, didn't have "load" wires. Then I get to the last 3 outlets, each is a 20 amp outlet (but with 15 amp plugs-ins on them instead of the different 20 amp plug-ins). 2 have "load" lines in addition to "line" lines. The circuit is a 20 amp circuit, which I read is code. So the the question is: since they are all on a line together, do I really need to buy 20 amp outlets to replace the other 20 amp outlets, or is it okay to use 15 amp outlets because they are all on the same breaker? I've read so many posts disagreeing in these forums about similar questions, so which is it?

Second question: my downstairs bathroom, next to the laundry room, had a 20 amp outlet. I bought a 15 amp GFCI duplex outlet with a nightlight built into it, specifically sold mentioning bathroom use. The breaker is a 20 amp breaker, but instead of just serving the bathroom (which I read is code), it was serving the laundry room as well. I went ahead and replaced the 20 amp outlet with the 15 amp outlet with the night light built in. My laundry room has a natural gas dryer (California), so just a standard 3 prong plug (doesn't make heat). The laundry room outlet was a standard 15 amp outlet, so I replaced it with a 15 amp GFCI. Please let me know what you think. Thank you.

 

All 15A receptacles (outlets) are rated for 20A passthrough. Which basically means you can only plug a 15A appliance into it, but you could use a total of 20A on the whole circuit. (Assuming of course 12ga wire and a 20A breaker). So in a residential setting, there's rarely any reason to use 20A receptacles, the ones with the "T" neutral.

Also, just to clarify, normal receptacles have two silver (neutral) screws and two brass (hot) screws. There's no in/out or line/load on them. GFI receptacles, if installed as the first receptacle on the string, have line/load receptacles that can protect downstream ones.

Similarly, replacing a 20A GFI with a 15A GFI is fine.

Code nowadays (for probably the past 10-15 years) has been that the bathroom requires its own dedicated GFI protected 20A circuit (with a few exceptions), and a laundry requires its own 20A circuit. Depending on when your house was built, your setup may have been correct at the time, which, until you do significant renovation, is still fine. Or possibly it was added to since then incorrectly.

 

Where are you installing the GFCI receptacles, and why?

One reason for this question is that you say No more than one GFCI device is needed on any circuit, and installing one on wiring that already has GFCI protection can cause problems. In addition, unless your laundry room has a sink that is less than 6 feet from the receptacle, GFCI protection is not needed or required for that receptacle.

15 amp GFCI receptacles are all you need in your house, as Zorfdt explained. In the downstairs bathroom, connecting the wires feeding out to the laundry room to the LINE terminals on the GFCI, and installing an ordinary 15A receptacle in the laundry - or just leaving the existing one in place - is all that is needed.