‘The worst that I’ve seen’: Plumber reveals why you should flush your tankless water heater—and what happens if you don’t

Here’s the truth: We could all probably do better with maintaining our household appliances, and the professionals never stop reminding us of it. But when a professional plumber shares a TikTok of what can happen to a chronically neglected water heater, it’s clear what all the fuss is about.

In a TikTok with over 1.6 million views as of Tuesday, content creator Plumbers Plunger (@theplumbersplunger) decides to open the back of a water heater that he had trouble flushing out. And what he finds is stomach-turning.