Water Heater Not Working? Troubleshooting Guide for Ottawa Homes

Symptom

Water comes out of every tap completely cold. No improvement even after running for several minutes.

Likely Cause

Gas unit: Pilot light out, faulty thermocouple, or gas valve failure. Electric unit: Tripped breaker, failed heating element, or thermostat malfunction.

✅ Try First

Check your circuit breaker panel for tripped breakers. For gas units, look at the pilot light window — if no flame is visible, follow the manufacturer’s relighting instructions on the tank label. Verify the gas valve is in the ON position.

🔧 Call a Pro If

Pilot will not stay lit after relighting, breaker trips again after resetting, or you smell gas. These indicate component failure requiring professional water heater repair.

Symptom

Water gets warm but not hot. Shower temperatures are lukewarm at best, even with the hot tap fully open.

Likely Cause

Thermostat set too low, sediment buildup insulating the bottom heating element, dip tube failure (cold water mixing with hot at the top of the tank), or a failing lower heating element on electric units.

✅ Try First

Check the thermostat dial on the tank. Health Canada recommends 60°C for storage tanks to prevent bacteria while avoiding scalding. If already set correctly, the problem is internal.

🔧 Call a Pro If

Temperature does not improve after adjusting the thermostat, or the tank makes rumbling noises (sediment). A technician can flush the tank, test elements, or replace the dip tube.

Symptom

Hot water starts fine but turns cold after 10–15 minutes. Second showers or back-to-back usage results in cold water.

Likely Cause

Sediment buildup reducing effective tank capacity, undersized tank for household demand, failed dip tube, or a failing lower heating element (electric). This is one of the most common hot water tank complaints from Ottawa families.

✅ Try First

Consider whether your household has grown or water usage increased. A 40-gallon tank may not serve 4+ people. If the tank is over 8 years old, sediment buildup is the most likely culprit.

🔧 Call a Pro If

A professional can flush the tank to remove sediment, test heating elements, or advise whether upgrading to a larger tank or switching to tankless makes more sense.

Symptom

Puddle of water around the base of the tank. May be a slow drip or an active leak. Floor drain may be overwhelmed.

Likely Cause

Internal tank corrosion (most common in tanks 8+ years old), leaking T&P (temperature and pressure) relief valve, loose drain valve, or condensation (which is normal on cold startup).

✅ Try First

Trace the leak source. Check pipe connections at the top for drips running down the side. Check the drain valve at the bottom is fully closed. If leaking from the T&P valve discharge pipe, do NOT cap it — this valve is a critical safety device.

🔧 Call a Pro If

Leak is from the tank body itself — this means internal corrosion and the tank cannot be repaired. A hot water tank replacement is the only solution. If the T&P valve is dripping, a technician should test and replace it.

Symptom

Rumbling, popping, or crackling sounds from the tank during heating cycles. May be loud enough to hear from adjacent rooms.

Likely Cause

Sediment buildup on the bottom of the tank. Ottawa has moderately hard water, and mineral deposits accumulate over years. Water trapped beneath sediment boils and creates the rumbling sound. This also reduces efficiency and can overheat the tank bottom, accelerating corrosion.

✅ Try First

If comfortable with DIY plumbing, you can flush the tank by connecting a garden hose to the drain valve and running water until it runs clear. This is a standard water heater maintenance task.

🔧 Call a Pro If

Noises persist after flushing, or the drain valve is stuck or leaks when opened. Severe sediment buildup in older tanks may not be fully removable — the tank may need replacement.

Symptom

Brown, orange, or rust-coloured water from hot taps only. Cold water runs clear.

Likely Cause

The anode rod — a sacrificial metal rod designed to attract corrosion away from the tank walls — is depleted. Once the anode is consumed, the tank itself begins to corrode internally. This is a major warning sign that the tank is approaching end of life.

✅ Try First

Run the hot water for 3–5 minutes to see if it clears. If discolouration is only after the tank has been idle (e.g. morning), it may be minor. Check cold taps — if both hot and cold are rusty, the issue is your water supply, not the tank.

🔧 Call a Pro If

Persistent rusty hot water means the anode rod needs replacement ($150–$300) or the tank is corroding beyond repair. A technician can inspect and advise whether a repair or replacement is the better investment.

Symptom

Hot water smells like sulphur or rotten eggs. Cold water smells normal.

Likely Cause

Bacteria reacting with the magnesium anode rod inside the tank, producing hydrogen sulphide gas. This is more common when the tank is set below 60°C or has been idle for extended periods. It is not dangerous but is unpleasant.

✅ Try First

Increase the thermostat to 60°C to kill bacteria. Flush the tank fully. If you have been away and the tank sat unused, running hot water throughout the house for 10–15 minutes may clear the smell.

🔧 Call a Pro If

Smell persists after flushing and temperature increase. The fix is replacing the magnesium anode rod with an aluminum/zinc anode, which eliminates the bacterial reaction. A straightforward repair for any licensed technician.

Symptom

Gas water heater pilot light goes out repeatedly. You can relight it, but it extinguishes within seconds to hours.

Likely Cause

Faulty thermocouple (most common — 70% of cases), dirty pilot orifice, drafts near the unit, or a failing gas control valve. The thermocouple is a safety sensor that detects whether the pilot flame is lit.

✅ Try First

Check for drafts near the water heater — nearby windows, dryer vents, or open doors can blow out the pilot. Ensure the area around the unit is clear. Try relighting carefully following the manufacturer’s instructions.

🔧 Call a Pro If

Pilot will not stay lit with no drafts present. Thermocouple replacement ($150–$250 installed) is a common repair that requires a licensed gas technician. Do not attempt gas component repairs yourself.