A standard standing pilot light burns approximately 600 to 1,800 BTU per hour, depending on the appliance. That translates to 5–12 therms of gas per month, costing roughly $5–$13/month at the 2026 national average gas price of $1.05/therm. Over a full year, a single pilot light costs approximately $60–$156 in gas — and if you have multiple gas appliances with standing pilots (furnace, water heater, fireplace), those costs compound.
Pilot Light Gas Usage by Appliance
| Appliance | Pilot BTU/Hour | Therms/Month | Cost/Month* | Cost/Year* |
|---|---|---|---|---|
| Gas furnace (older models) | 900–1,200 | 6.5–8.6 | $6.80–$9.05 | $82–$109 |
| Gas water heater | 600–1,000 | 4.3–7.2 | $4.50–$7.55 | $54–$91 |
| Gas fireplace | 1,000–1,800 | 7.2–13.0 | $7.55–$13.65 | $91–$164 |
| Gas stove/range | 400–600 | 2.9–4.3 | $3.05–$4.50 | $36–$54 |
| Gas dryer | 400–600 | 2.9–4.3 | $3.05–$4.50 | $36–$54 |
How to calculate your cost: Pilot BTU/hour × 24 hours × 30 days ÷ 100,000 BTU/therm × your local $/therm = monthly cost. For a 1,000 BTU/hr pilot: 1,000 × 24 × 30 ÷ 100,000 × $1.05 = $7.56/month.
Multiple Pilot Lights Add Up
Many older homes have 2–3 gas appliances with standing pilot lights. The combined cost is significant:
| Scenario | Pilot Lights | Combined Monthly Cost | Annual Cost |
|---|---|---|---|
| Furnace only | 1 pilot (1,000 BTU/hr) | $7.50 | $90 |
| Furnace + water heater | 2 pilots (1,800 BTU/hr total) | $13.60 | $163 |
| Furnace + water heater + fireplace | 3 pilots (3,400 BTU/hr total) | $25.70 | $308 |
| All gas (furnace + WH + fireplace + stove) | 4 pilots (4,000 BTU/hr total) | $30.25 | $363 |
A home with 3 standing pilot lights could save $200–$300+ per year by upgrading those appliances to electronic ignition models.
Pilot Light vs. Electronic Ignition
Modern gas appliances use electronic ignition (either hot surface ignition or direct spark) instead of standing pilot lights. Electronic ignition uses gas only when the burner actually fires — consuming zero fuel when the appliance is idle.
| Feature | Standing Pilot Light | Electronic Ignition |
|---|---|---|
| Gas use when idle | 600–1,800 BTU/hr (always) | 0 BTU/hr |
| Annual idle cost | $60–$160 per appliance | $0 |
| Reliability | Very reliable (no electrical parts) | Very reliable; igniter lasts 3–7 years |
| Electricity needed | No | Yes (minimal — uses furnace power) |
| Relight after outage | Manual relighting required | Automatic restart |
| Safety | Always burning (small fire risk) | No flame when system is off |
| Found in | Pre-2010 furnaces, some fireplaces | All modern furnaces (post-2010) |
Should You Turn Off Your Pilot Light in Summer?
For gas furnaces, the pilot light only runs during the heating season (if you shut off the furnace in spring). However, for gas fireplaces and older water heaters with standing pilots, the pilot burns year-round — even when you're not using them.
Gas fireplace: Yes, turn off the pilot in summer. A gas fireplace pilot costs $7–$14/month for zero benefit during warm months. That's $28–$56 saved over a 4-month summer. Most gas fireplaces have a clearly labeled pilot switch.
Gas water heater: Generally, leave it on. The pilot also helps dry out the combustion chamber, preventing corrosion. The savings from turning it off ($4–$8/month) are modest, and relighting can be inconvenient.
Gas furnace: If your furnace has a standing pilot (pre-2010 model), turn it off for the summer. Savings: $7–$9/month × 4 months = $28–$36. When fall arrives, follow the relighting instructions on the furnace.
Turning Off a Standing Pilot Light
Standing pilots are still common on older water heaters (pre-2005 Rheem, AO Smith), gas fireplaces, and some legacy gas ranges. To turn off:
Water heater (typical):
- Locate the gas control valve (round black or brass valve near the bottom of the tank).
- Rotate the pilot selector knob from ON to PILOT to OFF. This closes the pilot gas orifice.
- Wait 5 minutes for residual gas to dissipate before any further work.
- To relight later, follow the manufacturer's ignition sequence — usually press the pilot knob down while holding an ignition source (piezo or manual match) to the pilot orifice for 30–60 seconds until the thermocouple heats.
Gas fireplace:
- Locate the wall switch or key valve — pilots on modern fireplaces are usually controlled via wall switch, not the appliance itself.
- Turn the wall switch to OFF, or rotate the gas key valve (usually near the fireplace floor) to the closed position.
- If the pilot has a millivolt-generator thermopile (not a simple thermocouple), it may take 15–30 seconds to fully extinguish after the valve closes.
Do NOT blow out a pilot light or plug the orifice with anything. Both create ignition and asphyxiation hazards.
Pilot Light Maintenance (When Present)
Standing pilots can develop three common problems:
-
Yellow/orange flame instead of blue — indicates incomplete combustion, usually from a dirty pilot orifice or from soot buildup on the burner. A properly-adjusted pilot burns steady blue with a small yellow tip. Clean the orifice by removing the pilot assembly (usually two Phillips screws) and gently blowing out debris with compressed air. Do not use a wire to clean the orifice — the opening is very small, and any metal probe will oversize it, which changes the pilot flame's gas flow and causes further problems.
-
Weak or wavering flame — check the thermocouple. Thermocouples produce a small millivolt signal when heated by the pilot flame, which holds open the gas valve's pilot circuit. If the signal drops below the valve's rated minimum (varies by valve manufacturer), the gas valve closes as a safety cutoff. Test with a multimeter set to millivolts DC across the thermocouple terminals at the valve — compare against the valve's spec-sheet minimum. Replacement thermocouples typically cost $10–25 and take about 15 minutes to swap.
-
Pilot goes out repeatedly — most often a bad thermocouple, but can also indicate a drafty install location (near a window or bathroom exhaust), a partially-clogged main burner orifice, or (rarely) a bad gas valve. Rule out drafts and thermocouple before assuming valve failure.
Modern intermittent-pilot ignition (IPI) systems avoid all of these — no standing flame to maintain. Any appliance with a standing pilot older than 20 years should be evaluated for replacement rather than repeated pilot repair. Modern high-efficiency units eliminate standing pilots for both safety and fuel-consumption reasons.
Key Takeaways
- A single standing pilot light costs $60–$160/year in gas — and most people forget they're running.
- Multiple pilot lights (furnace + water heater + fireplace) can cost $200–$360/year combined.
- Modern electronic ignition uses zero gas when idle — upgrading to new appliances eliminates pilot light costs entirely.
- Turn off gas fireplace pilots in summer — this is the easiest immediate savings ($28–$56).
- Don't leave the furnace pilot running in summer if your furnace has a standing pilot (pre-2010 models).
- Post-2010 furnaces use electronic ignition and don't have standing pilots — there's nothing to turn off.
- When replacing gas appliances, electronic ignition is now standard — but verify if buying budget or older-stock models.
Frequently Asked Questions
A properly burning pilot light produces minimal CO. However, a pilot in a poorly ventilated area, or one that burns with a yellow/orange flame (indicating incomplete combustion), can produce elevated CO levels. Ensure adequate ventilation around gas appliances and install CO detectors on every floor. A healthy pilot flame is small, steady, and primarily blue.
Sources
Sources & References
Related Articles
Related Articles
Best Electric Furnace Brands & Cost (2026 Buyer's Guide)
comparison • 14 min read
Cold Air Return Vents: What They Are & How Many You Need
guide • 9 min read
What Does a Dirty Furnace Filter Look Like? (4 Stages)
guide • 8 min read
Do Furnaces Have Pilot Lights? Which Ones Still Do (and Which Don't)
guide • 17 min read