Why is my energy bill suddenly so high?

Compare usage rather than dollars first. A jump in units used points to equipment, weather or a new load. A jump in cost with flat usage points to a rate change.

Last reviewed 2026-07-15

Rates change independently of behaviour, so a bill can rise with no change in how you live. Read the usage figure — kWh, therms or CCF — against the same month last year before assuming a fault.

If usage genuinely increased, the most common causes are a restricted or dirty filter, an unusually severe weather month, a failing appliance running longer than it should, a heating element or auxiliary heat engaging unexpectedly, or a device left running.

What to check first

  • Compare units used, not dollars, to the same month last year
  • Check the HVAC filter and replace it if loaded
  • Look for continuous running: HVAC never reaching setpoint, well pump cycling, water heater always hot to the touch
  • Check whether a rate change or seasonal tier applies on your bill
  • Confirm no space heaters, dehumidifiers or pool equipment started running recently

When to call a professional

  • The heating or cooling system runs continuously and cannot reach setpoint
  • You smell gas, or a combustion appliance shows soot or rust streaking
  • Breakers trip repeatedly or wiring feels warm