Why won't my water heater pilot light stay lit or spark?
A lack of consistent spark forces people to hold the pilot button down until their fingers hurt while trying to light the unit. Because the pilot light ultimately won't stay lit, the system fails to ignite or operate.
What the numbers show
Counted from the threads quoted below. How we count
- People have been saying this in most months since September 2026.
- This comes up 17.1× more often in r/hvacadvice than across the site as a whole.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1Replacing the thermocouple2 people mentionedDid this help you?
- 2jiggling the wire through the rubber grommetDid this help you?
- 3waiting to find replacement parts locally to change out the igniter tip and pilot assemblyDid this help you?
- 4Calling out a professional plumber or HVAC technicianDid this help you?
- 5Don’t touch it thenDid this help you?
- 6Take the connection apart where the yellow and red wire connect and clean it well.Did this help you?
- 7Holding the starter knob down for several minutes to flush air bubbles from the gas lineDid this help you?
- 8Cleaning dust from the inside of the heaterDid this help you?
- 9Realigning the pilot nozzle/hood to increase voltage outputDid this help you?
- 10Heating the disconnected thermocouple with a lighter to test itDid this help you?
- 11Tapping the side of the gas valve with a wrench to unstick it.Did this help you?
- 12Taking out the pilot tube and blowing through it to check for clogs.Did this help you?
- 13Cleaning the thermocouple with sandpaper or a Scotch-Brite pad.Did this help you?
- 14Holding the pilot button down for around a minute before releasing it to ensure the thermocouple heats up.Did this help you?
- 15Temporarily bypassing the thermal cut-off switch by jumping the two wires togetherDid this help you?
- 16Calling a professional plumber to fix itDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“when we went to light the pilot light on my water heater there was no spark to light the pilot.”source ↗
“I followed all instructions and no spark. Well there was maybe 2 sparks in 200 attempts.”source ↗
“Nothing consistent and my fingers hurt holding the pilot button down.”source ↗
“The pilot lights while I hold the red button but goes out when I release it, even after holding it for 3–4 minutes.”source ↗
“The pilot flame is blue, and the thermocouple tip glows red, but the pilot still goes out when I release the button.”source ↗
“My pilot light turns off randomly as well. I wanted to replace this wire/plug to see if it fixes that issue”source ↗
“Last winter it stopped working and we said we’d deal with it next season. It seems to be an issue with the pilot light.”source ↗
“Now it will turn on briefly, but go out.”source ↗
“Replace the thermo coupler.”source ↗
“Hi, I have an older Lennox furnace that I can't get to start.”source ↗
“It seems like there isn't any gas coming out to manually light the pilot with a lighter.”source ↗
“I had cut the power to the furnace for a couple weeks in the summer at the breaker and haven't been able to get it going since for heat.”source ↗
“I’m alone working reception at a hotel right now and our hot water heater stopped firing.”source ↗
“I hear no clicking or ignition spark at all”source ↗
“Is there anything basic I can safely try, like a reset, power cycle, switch, loose connector, etc.?”source ↗
“Pilot light went out. I heave tried re lighting it but have had no luck.”source ↗
“I found this piece that looks like it's loose. Any idea if this could be the cause?”source ↗
“Trying here before I call in a professional. Trying g to DIY it if possible, but I also don't want to burn down the house.”source ↗
“Pilot light won't stay lit.”source ↗