Pilot Light Cost Calculator
| Pilot rate ↓ · gas price → (8-month season) | $1.00 | $1.50 | $2.00 |
|---|---|---|---|
| 300 BTU/h (oven) | $17.28 | $25.92 | $34.56 |
| 600 BTU/h (furnace) | $34.56 | $51.84 | $69.12 |
| 900 BTU/h (old boiler) | $51.84 | $77.76 | $103.68 |
Pick the appliance and your gas price. The calculator converts the pilot burner rate into therms, prices the flame per month and across the months you keep it lit.
The pilot is the one load in the house that never cycles: 600 BTU an hour sounds like nothing until it runs 24 hours a day for eight months, quietly out-burning a space heater evening every eleven days. Modern furnaces with electronic ignition already saved this money; the standing flame is a legacy tax on older equipment.
How to use
- Pick the pilot rate: ovens typically run about 300 BTU per hour, furnace and boiler pilots nearer 600, old boilers up to 900.
- Gas price comes off the utility bill in dollars per therm.
- Set the lit months: eight for a seasonal furnace, twelve for a water heater kept lit year-round. The season cost updates live.
Frequently asked questions
How much gas does a pilot light use?
Standing pilots burn roughly 300 to 900 BTU per hour by appliance - call it 600 for a typical furnace. That is 0.144 therm a day, about 4.3 therms a month, which the calculator prices at your rate before you decide whether it is worth the flame.
How much does a pilot light cost per month?
About 6.50 dollars a month at 600 BTU per hour and 1.50 dollars a therm - 1.5 therms a week for a flame whose only job is to be ready. Over an eight-month heating season that is north of 50 dollars, and a year-round water heater pilot doubles it.
Should I turn the furnace pilot off in summer?
For a seasonal furnace or boiler, yes: with the unit off the pilot is pure standby loss, and eight summer months of it can exceed a winter month of actual heating. Water heaters are the nuance - many manufacturers prefer them lit year-round for flue moisture control, so follow the manual, not the generic rule.
Do modern furnaces even have pilot lights?
Most furnaces built in the last couple of decades use electronic ignition - a spark or hot-surface igniter that lights the burner only when heat is called. No standing flame, no standby tax. An old pilot furnace nearing replacement should tip the scales, since the ignition upgrade alone pays a slice of the new unit.
Why is my pilot flame so big?
Pilots are orifice-metered: a flame much taller than the appliance spec usually means a replaced or wrong orifice, and it burns proportionally more gas around the clock. The manual lists the flame shape - a steady soft blue cone, not a roar - and the calculator lets you price exactly what the excess is costing.