Summary:
A leaking water heater is usually caused by loose connections, a failing temperature and pressure (T&P) relief valve, corrosion inside the tank, or excess pressure buildup. Small leaks may be repairable, but tank leaks almost always mean replacement.
Discover the most common reasons your water heater leaks — from faulty valves to tank corrosion. Learn when repair is possible and when replacement is needed.
Common Reasons Your Water Heater Leaks
1. Loose or Faulty Connections
Inlet and outlet pipes at the top of the heater may loosen over time. Tightening or resealing often solves minor leaks.
2. Temperature & Pressure Relief Valve (T&P Valve)
If the T&P valve is faulty or the system pressure is too high, it will release water as a safety measure. Ignoring this can be dangerous.
3. Corrosion Inside the Tank
Over years of use, sediment buildup and rust eat away at the tank liner. Once the steel tank corrodes, replacement is the only solution.
4. Drain Valve Issues
The drain valve near the bottom can develop drips if not fully closed or if its washer wears out.
5. Excess Water Pressure
High municipal water pressure or a missing expansion tank can force water out of the heater and damage plumbing fixtures.
What To Do Next
- Check connections for tightness.
- Inspect the T&P valve and ensure pressure is within code.
- Look for corrosion — if the tank itself is leaking, replacement is required.
- Call a licensed Mississuga plumber for diagnosis before the problem worsens.
Final Note
Delaying water heater repairs risks flooding, mould growth, and energy inefficiency. A professional inspection ensures your system is safe and code-compliant.
👉 For fast, reliable water heater repairs in Mississauga & Toronto, contact Select Plumbing and Heating today.
Q1: Why is water leaking from the top of my water heater?
Leaks at the top often come from loose inlet or outlet pipe connections. Tightening or resealing usually resolves the issue.
Q2: Why is my water heater leaking from the bottom?
Bottom leaks typically mean tank corrosion or a faulty drain valve. If the tank itself is rusted, replacement is necessary.
Q3: Can a leaking water heater be repaired?
Minor leaks at valves or connections can be fixed, but leaks from the tank body cannot — the unit must be replaced.
Q4: Is it dangerous if my water heater is leaking?
Yes. Leaks can cause water damage, mould, and electrical hazards. A leaking T&P valve may also indicate unsafe pressure levels.
Q5: How long should a water heater last in Canada?
Most water heaters last 8–12 years. Regular maintenance like flushing the tank can extend lifespan.
