Safety boundary: Do not remove electrical covers, reset high-limit controls repeatedly or work on gas burners.
Whole house or one fixture
A single problematic faucet or shower may have a cartridge or mixing issue. Whole-home loss points toward the water heater, energy supply or controls.
No heat versus not enough
A system that never heats differs from one that recovers slowly or runs out during peak use. Note recent demand and whether temperature returns later.
Tankless patterns
Minimum flow, scale, inlet temperature, blocked screens or error codes can affect operation. Photograph codes rather than repeatedly power-cycling.
Prepare for service
Record model, fuel, age, symptoms, leaks, breaker status and whether other gas appliances operate. Keep clear of combustion and electrical compartments.
Useful questions to record
- Is the problem at one fixture or throughout the home?
- Is there active leakage or relief-valve discharge?
- What fuel, capacity and age is the unit?
Related guides
Tank, Tankless and Heat-Pump Water HeatersA Canadian comparison of storage tanks, on-demand systems and heat-pump water heaters.Sizing a Water HeaterHow first-hour delivery, recovery and peak demand matter more than tank volume alone.Water Heater Leaks and MoistureHow to identify the source area and protect the building without unsafe repairs.Water Heater MaintenanceA conservative maintenance plan for tanks and tankless units.