A leaking water heater is one of those problems that can sneak up on you. One day it’s a small puddle, the next your basement could be partially flooded. In Mississauga, where many homes have finished basements and tight utility spaces, this kind of leak can do real damage fast.
Whether it’s a steady drip or full-on pooling water under your tank, you need to act fast. In this guide, we’ll cover what causes water heaters to leak, what to do next, and when it’s time to call in the pros.
Common Reasons for Water Heater Leaking
Not every leak is the same. Some causes are quick fixes, while others may point to major issues requiring immediate attention or even full replacement. Here’s what typically causes a leaking hot water tank or tankless system in GTA homes:
- Loose connections: The inlet or outlet pipes may have shifted or loosened from normal wear and tear or vibrations in the plumbing system. Even minor drips at the top of your unit can lead to water damage over time.
- Corroded tank: Sediment from GTA’s hard water builds up inside your water heater tank over time, eventually rusting the inner lining. This corrosion often leads to cracks or pinhole leaks, especially in older models.
- Faulty temperature & pressure relief (T&P) valve: This safety valve protects your tank from excess pressure. If it malfunctions or is stuck open, water can leak continuously from the side of the heater.
- Leaking drain valve: Located near the bottom of the unit, this valve is used to flush the tank. When it’s worn out or not fully closed, it can drip slowly or even release more water than expected.
- Excess pressure: If your water pressure is too high or your thermostat is set too high, pressure can build up in the tank. This can force water out of the T&P valve or create stress cracks in fittings.
- Condensation: Especially in cool or damp basements, a cold tank can create condensation on the outside, which may appear like a leak. While this isn’t a system failure, it can still lead to moisture problems around the unit.
According to expert plumbers from Anta Plumbing in GTA, understanding these leak causes helps you know when to tighten a fitting and when to call in a professional for a full inspection or replacement.
Step-by-Step: What to Do If You Discover a Leak
If you spot water near your heater, follow these immediate steps. Reacting quickly can help you avoid major damage to flooring, walls, or surrounding equipment.
- Confirm the source. Check carefully if the water is coming directly from the heater, the connecting pipes, or just condensation from a humid room. Dry the area and observe the heater closely.
- Turn off the power.
- Gas unit: Switch the gas valve to OFF to stop fuel from reaching the burner.
- Electric unit: Go to your electrical panel and flip the breaker controlling the water heater to the OFF position to prevent the risk of shock.
- Shut off the cold water supply. Usually located at the top of the unit, turning this valve off will stop the water supply and prevent additional leaking.
- Drain the tank if needed. If water is pooling excessively, attach a garden hose to the drain valve at the bottom of the unit. Run the hose to a nearby floor drain or outside. Open the valve carefully and be aware that the water may be hot.
- Clean up the water. Use towels, a wet/dry vac, and set up fans to dry the area completely. This helps prevent long-term moisture damage and mould growth in your basement or utility room.
- Call a professional. Our certified and trusted local experts in the GTA can inspect and fix the issue quickly.
Even if the leak seems minor, don’t wait; it could worsen quickly and turn into a major problem.
Is a Leaking Water Heater a Safety Hazard?
Yes, and often more than people realize. Common hazards include:
- Electrical risk: Water and electricity don’t mix. If your heater is electric, shut off the power immediately.
- Gas risk: Gas leaks or backdrafting can occur near faulty water heaters. If you suspect a gas leak, evacuate and call professionals immediately.
- Water damage: Finished basements and utility rooms can flood quickly.
- Mould growth: Leaks that go unnoticed for 24–48 hours can trigger serious health issues.
If you’re unsure, it’s safer to shut everything off and call a pro.
Repair or Replace? Here’s How to Decide
If your heater is newer and the leak is coming from a valve or fitting, a repair is likely enough. These are parts that can be tightened or replaced at low cost.
However, if the tank itself is leaking from the bottom, or if the unit is over a decade old, it’s usually smarter to go with a replacement. Not only will you avoid repeated repairs, but you’ll benefit from better energy efficiency and hot water performance.
We handle both traditional water heater installations and tankless water heater upgrades for homes across Mississauga.
Learn more: Water heater repair guide
Can You Prevent This From Happening Again?
Absolutely. One of the easiest ways to avoid water heater leaks is to stay on top of maintenance. This includes flushing out sediment, checking all valve connections, and testing the temperature and pressure relief valve once a year.
At HVAC Group, we offer scheduled maintenance services for both tank and tankless models. It’s a small investment that can extend your heater’s lifespan and reduce repair costs down the line.
We also cover signs and steps in detail here: Water Heater Maintenance Tips
Why Choose HVAC Group for Water Heater Leaking Repair
When your water heater leaks, you need help from a local team that shows up fast and gets the job done right. Here’s why GTA homeowners trust HVAC Group:
- Same-day service across the GTA: We know time matters when there’s water on your floor. We’re fast to respond, anywhere in the Greater Toronto Area.
- Certified technicians with experience: Our crew knows hot water systems inside and out. We handle complex repairs efficiently, saving you time and stress.
- Full-service solutions: Whether it’s a small leak or full unit failure, we offer everything from repairs and replacements to ongoing maintenance plans.
- All makes and models covered: Gas or electric, tank or tankless, we work on them all, regardless of age or brand.
- Upfront pricing with no pressure: We don’t believe in upselling. We give honest quotes and let you decide what works for your home and budget.
You can also check out our Google Reviews to learn what others are saying about us.
Final Words
A water heater leaking can quickly lead to costly damage and safety hazards. Don’t wait—shut off the power, stop the water flow, and call HVAC Group. We offer fast, reliable water heater repair and replacement across the GTA. Our certified technicians handle all makes and models with same-day service.
Book your service now and let us fix it before it gets worse.
