A pilot light that keeps going out means no hot water, and a cold shower is a rough way to find out. The flame is small, but the reason it keeps dying usually points to a part that needs attention. Most causes are fixable, and a few you can sort out yourself.
Below are the real reasons a water heater pilot light keeps going out on calls across Milton and Halton Region, plus how to fix each one.
How the Pilot Light Works
On a gas water heater, the pilot is a small flame that stays lit at all times. Its job is to light the main burner when your tank needs to heat water. No pilot means no burner, and no burner means no hot water.
A safety part called the thermocouple sits right in the pilot flame. It senses the heat and tells the gas valve the pilot is lit. If that flame goes out, the thermocouple shuts off the gas so it cannot leak into your home. That safety system is also why a weak or failing part often shows up as a pilot that will not stay lit.
Why Your Pilot Light Keeps Going Out
A pilot that dies once might just need a relight. A pilot that keeps going out has a cause worth tracking down. Here are the most common ones.
1. A failing thermocouple
This is the top cause. The thermocouple senses the pilot flame and keeps the gas flowing. When it weakens or gets coated in soot, it misreads the flame and shuts the gas off, so the pilot dies. A new thermocouple is an inexpensive part and a common fix.
2. A dirty pilot tube or orifice
The small opening that feeds the pilot can clog with dust, soot, or debris. A starved flame burns weak and goes out easily. Cleaning the tube often brings the flame back to a strong, steady blue.
3. A draft or venting problem
A strong draft can blow the pilot out. So can a blocked or backdrafting vent. If your pilot dies on windy days or after the furnace kicks on, air movement around the unit may be the culprit. This one is worth a closer look, since a venting fault can be a safety issue.
4. A bad gas valve
If the thermocouple and pilot tube check out, the gas control valve itself may be failing. This is a bigger repair and usually one for a licensed plumber, since it controls gas flow to the whole unit.
5. A nearly empty propane tank or gas supply issue
If you run on propane, a low tank starves the pilot. On natural gas, a supply drop or a partly closed shutoff does the same. Rule this out before chasing parts.
How to Relight the Pilot Safely
If your pilot went out, you can often relight it yourself. Go slow and trust your nose.
- Turn the gas control knob to “Off” and wait at least five minutes. This lets any built-up gas clear.
- If you smell gas at any point, stop. Leave the house and call your gas provider from outside.
- Turn the knob to “Pilot” and hold it down. Press the igniter button, or hold a long lighter to the pilot.
- Keep the knob held down for about a minute after the flame lights. This lets the thermocouple warm up.
- Release the knob. If the flame stays lit, turn the knob to “On.”
If the pilot dies the moment you let go of the knob, the thermocouple is the likely culprit. If it will not light at all, you may have a gas supply or valve problem.
When to Call a Plumber
A one-time relight is fine to do yourself. A pilot that keeps dying, or one that will not light at all, is your sign to call. Gas appliances are not the place to guess.
Call a plumber when:
- The pilot goes out again within hours or days
- It will not stay lit after a proper relight
- You smell gas near the unit
- The flame is yellow or orange instead of blue
- The unit is old and the trouble keeps stacking up
A pilot that keeps dying can also be one of the early signs your unit is wearing out. If yours is aging, read our guide on the signs your water heater is failing to see where it stands.
What a Repair Costs
Most pilot light repairs are quick and affordable. A water heater repair starts at about $149, and a thermocouple swap is often a same-visit fix. Cleaning a clogged pilot tube falls in the same range.
If the gas valve has failed or the tank is near the end of its life, we tell you straight whether a repair or a replacement is the smarter spend, with no pressure to upsell. Our water heater repair and installation page walks through both paths. You get a flat quote before any work starts, so the price you approve is the price you pay.
Repair or Replace?
One cheap part does not mean you need a new water heater. But if your unit is 10 years or older and the pilot trouble comes with other problems, the math can shift.
A failing thermocouple on a younger tank is an easy fix worth making. The same problem on a rusting 12-year-old tank may be the last in a string of repairs. We look at the age, the parts, and the cost, then give you an honest call.
What to Do Next
If your pilot light went out once, try the relight steps above. If it keeps dying, do not keep fighting it, since a steady gas problem is worth a professional eye.
Call us at (289) 367-8218 or request a free estimate and we will track down why your pilot keeps going out and quote the fix flat-rate. We serve Milton, Georgetown, Acton, Oakville, and the rest of Halton Region, with 24/7 help if you lose hot water after hours.
Frequently Asked Questions
Why does my water heater pilot light keep going out?
The most common cause is a failing thermocouple, the safety part that senses the pilot flame and keeps the gas on. When it weakens or gets dirty, it shuts the gas off and the pilot dies. Other causes include a clogged pilot tube, a draft or venting problem, a bad gas valve, or a low gas supply.
Is it safe to relight the pilot light myself?
Usually, yes, if you follow the steps and trust your nose. Turn the gas off and wait at least five minutes first. If you smell gas at any point, stop, leave the house, and call your gas provider from outside. If the pilot will not stay lit after a proper relight, call a plumber instead of trying again and again.
How much does it cost to fix a pilot light that won’t stay lit?
A water heater repair starts at about $149, and a thermocouple replacement is often a same-visit fix in that range. Cleaning a clogged pilot tube is similar. If the gas valve has failed, the repair costs more, and we quote it flat-rate before any work begins.
Why is my pilot flame yellow instead of blue?
A healthy pilot flame is blue and steady. A yellow or orange flame usually means the pilot is not getting enough clean air, often from a dirty tube or a venting issue. It can also signal incomplete combustion, which is worth checking. Have a plumber look at it rather than leaving it.
Should I repair or replace a water heater with pilot problems?
If the unit is under 8 years old and the fix is a cheap part like a thermocouple, repair is the clear call. If the tank is 10 years or older, rusting, or stacking up repairs, replacement is often the smarter spend. We weigh the age and cost and give you a straight answer.