Pour a pot of hot (not boiling) water down the drain. If it sits there for 10 minutes then suddenly drains with a "glug," it was almost certainly ice melting. How to Thaw a Frozen Tub Drain (Safely) Warning: Never use an open flame (propane torch, lighter, heat gun on high) on metal or PVC pipes. You can start a house fire or melt plastic fittings.
| Symptom | Frozen Drain | Clogged Drain | | :--- | :--- | :--- | | Water drains very slowly or not at all | ✅ | ✅ | | Happens suddenly during a cold snap | ✅ | ❌ | | Other drains (sink, toilet) work fine | ✅ | ❌ (if main line is clogged) | | You hear gurgling from other fixtures | Sometimes | Often | | Cold draft coming from drain opening | ✅ | ❌ | tub drain frozen
Before you panic or reach for a blowtorch, here is everything you need to know about why this happens, how to fix it safely, and how to prevent it from happening again. It seems counterintuitive. Your bathroom is inside your heated home, so how does the drain freeze? Pour a pot of hot (not boiling) water down the drain