I tried adding “to change”, or “to change something”, both being used as a transitive verb, to this vocab word. But it gets flagged as a blocked synonym. I was thinking along the lines of “to change a tyre”, which I believe is an appropriate use of 代える. Even in the contextual examples of the word, under the ～を代える section, it has nothing but “to change” translations. Thoughts?
NB I hope this is the correct category for this post, there’s kinda a lot of them 
I guess, even if they want you to know it can mean “change”, per the examples, it’s not any type of change, but replace/substitute/exchange. That is, the thing doesn’t undergo change, but is changed for something else. As opposed to 変える.
There’s no way to get that difference in nuance while just keeping it as “change”.
Hey Joris914!
I think @Kazzeon is correct that there is a nuance between 変える and 代える, which is why “to change” is on the block list. I do think that there could be some work done on the patterns of use translations though to avoid any confusion! I will bring this up to the content team for review. 
-Nick at WK
Hey Joris,
Here are some changes we made to the various “To change” verbs that we have on WaniKani:
代える (10) - We replaced a common word combination, updated the translations for four common word combinations, and moved “to change” and “to change something” from the block list to the warning list. We also updated common word combinations:
ちがうものに代える
to replace with a different thing
これに代える
to substitute with this
ピッチャーを代える
to replace the pitcher
水を代える
to replace the water
ことばを代える
to use different words
変える (15) - We updated the meaning explanation with the following text:
変える and 代える sound the same and are sometimes used in similar contexts, but are different in nuance. 変える refers to the act of making something different, and involves altering the nature or state of something. For example, changing the layout of a room or changing one’s perspective on an issue. 代える means to substitute or exchange one thing for another that is expected to fulfill the same role, use or purpose, such as replacing a worker with a substitute.
替える (25) - We added “to change” and “to change something” to the warning list and updated the meaning explanation and the context sentence translation with the following text:
替える means to replace something with another item of the same kind or equivalent, rather than changing its state. Wondering how it differs from 代える? While 代える stresses that you’re using someone or something “in place of another,” 替える simply indicates the act of swapping one thing for another similar thing.
お父さんに電球を替えるようにもう頼んだよ。
I already asked dad to replace the light bulb.
換える (36) - We removed “to change” from the block list and added “to change” and “to change something” to the warning list and updated the meaning explanation with the following text:
Wondering about the difference between 替える and 換える? 替える means swapping one thing for another of the same kind, whereas 換える means exchanging or trading one thing for something different, often of similar value. So, you use 替える when switching out light bulbs, but opt for 換える when trading jewelry for cash.
Hopefully this clarifies things a little, thanks again for the feedback!