I heard that shortly after the installation was made, it started rusting.
ご質問ありがとうございます。
「取り付けて程なくして錆びたって話を聞いたけど」は英語で「I heard that shortly after the installation was made, it started rusting.」と言います。
また、文脈で「この[換気扇](https://eikaiwa.dmm.com/uknow/questions/36997/)がいいって勧められましたが、違う人からは取り付けてけっこーすぐに錆びたって話を聞きました。」と言いたいなら、英語で「I heard from a different person that shortly after the installation of this fan was done, it started rusting.」と言えます。
ご参考になれば幸いです。
I was told this range hood was good, but someone else told me his started rusting not long after it was installed.
この場合、次のような言い方ができます。
ーI was told this range hood was good, but someone else told me his started rusting not long after it was installed.
「この換気扇は良いと言われたが、別の人は取り付けられて程なくして錆だしたと言っていた」
range hood「換気扇」
to start rusting「錆始める」
not long after「程なくして」
ご参考まで!