You live in your parents' home. It's Chol Ha'moed. There are four bathrooms. You use one of them, and the toilet clogs. Is it permissible for you to plunge it during Chol Ha'moed?
Please explain your reasoning.
(I've done some Web searches. So far, I have found a discussion of repairing toilets during Shabbat, and during Erev Pesach, but not during Chol Ha'moed.)