Water Heater Leaking? What to Do Right Now (and When to Call an Ottawa Pro)

Finding a puddle around the base of your tank is stressful, especially when the water heater sits in a finished basement. A water heater leaking doesn't always mean disaster, but it always means you should act quickly. Some leaks are simple fixes; others are a sign that the tank is failing and could let go completely.

Here's what Ottawa homeowners should do the moment they notice a leak, how to figure out where it's coming from, and when it's time to call a licensed technician.

First: Is It Safe?

Before you do anything else, check for these warning signs:

• Smell of gas (rotten eggs): Do not touch any switches, do not try to find the leak, and do not use your phone inside. Leave the home right away and call the Enbridge Gas emergency line or 911 from outside.
• Carbon monoxide alarm sounding: Get everyone out and call 911 from outside.
• Water near electrical outlets or panels: Stay out of standing water and keep away from anything electrical. If you can't safely reach the breaker, call for help.

If none of these apply, you can move on to the next steps.

Water Heater Leaking? What to Do Step by Step

Follow these steps in order to limit damage and keep your home safe.

1. Turn off the water supply

Find the cold water inlet pipe at the top of the tank and close its shut-off valve. This stops new water from entering the tank. If you can't find it or it won't turn, shut off the main water valve to the house.

2. Turn off the energy source

• Gas water heater: Turn the gas control knob to the "Off" or "Pilot" position. Do not attempt any gas line work yourself.
• Electric water heater: Switch off the dedicated breaker at your electrical panel.

3. Contain the water

Move boxes, rugs and stored items away, and use towels, a wet-dry vacuum or a pan to control the spread. In finished basements, acting fast helps protect drywall, flooring and baseboards.

4. Don't drain the tank unless you're comfortable doing it

The water inside can be scalding. If the leak is heavy, a technician can drain it safely. If you do drain it, let it sit to lose heat first and run a hose to a floor drain.

5. Call a professional

Once things are under control, book a technician. For an active, heavy leak, call KAD Mechanical & HVAC at (613) 790-2675 to book a repair or water heater replacement.

Water Heater Leaking From the Top, Bottom or Valve? Finding the Source

Where the water is coming from tells you a lot about how serious the problem is. Wipe everything dry, then watch carefully.

Leaks from the T&P relief valve

The temperature and pressure relief valve is a critical safety device. It opens to release water if the tank gets too hot or the pressure gets too high. If it's dripping or discharging, the valve itself may be worn — or it may be doing its job because something else is wrong, such as a thermostat issue or high water pressure. Never cap or plug this valve. Have it checked by a professional.

Condensation versus a real leak

Gas water heaters can produce some condensation, particularly when very cold water enters the tank. In Ottawa, incoming water gets especially cold in winter, so a little moisture under a freshly refilled tank isn't always a leak. If water keeps appearing once the tank is fully heated, it's time for an inspection.

Repair or Replace a Leaking Water Heater?

Leaks from fittings, valves or connections can usually be repaired. But if water is coming from the tank body, there's no reliable fix — the inner lining has failed and the tank needs to be replaced. Corrosion only gets worse, and a small weep can turn into a burst tank without warning.

Consider replacement if:

• Water is leaking from the tank itself.
• You see rust on the tank, in the water or around the base.
• The heater is around 10 years old or more.
• You've had several repairs recently.
• You're also dealing with lukewarm water, rumbling noises or rising Enbridge Gas bills.

If it's time for a new unit, our water heater installation team installs both tank and tankless models. Costs vary with the type and size of heater, venting, and any gas or plumbing changes needed, so we'll give you an upfront price before work begins.

If your water heater is a rental

Many Ottawa homes, especially older properties in areas like Alta Vista, Westboro and Orleans, still have rented water heaters. If yours is a rental, check your agreement and contact the rental company, since they may be responsible for repair or replacement. If you'd like to explore owning your heater instead, we're happy to talk through your options.

How to Prevent Water Heater Leaks

Most leaks don't happen overnight. They're the result of years of sediment, corrosion and wear. A little prevention goes a long way:

• Book yearly maintenance: A technician can flush sediment, test the T&P relief valve and inspect fittings. Our furnace and water heater maintenance covers both appliances in one visit.
• Check the anode rod: This sacrificial rod protects the tank from rust. Replacing it before it's used up can extend tank life.
• Watch your water pressure: Pressure that's too high puts strain on the tank and valves.
• Look around the tank monthly: A quick glance for drips, rust or moisture can catch problems early.
• Install a drain pan or leak sensor: Especially useful if your heater is in a finished basement.

Why Ottawa Homeowners Call KAD

KAD Mechanical & HVAC has more than 10 years of experience and over 500 completed projects across Ottawa, Kanata, Nepean, Barrhaven, Orleans and the surrounding areas. Our certified, TSSA-licensed gas technicians handle diagnosis, repair and replacement, with upfront pricing and no hidden fees. You can see examples of our work in our project gallery.

Water heater leaking? Call us at (613) 790-2675 for fast, reliable water heater repair, or request a free quote for a replacement.

Frequently Asked Questions

Written by the KAD Mechanical & HVAC team

Certified, TSSA-licensed heating, water heater and gas technicians serving Ottawa, Kanata, Nepean, Barrhaven and Orleans for 10+ years.

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