No hot water and a cold tank usually means the pilot light has gone out. This is one of the most common water heater issues. Fortunately, in most cases you can fix it yourself in a few minutes. Here’s how to do it safely and what to check if the pilot won’t light. We’ll also cover when the problem indicates something more serious.
Before You Start: Safety Check
If you smell gas near the water heater, do not attempt to relight the pilot. Leave the house immediately, don’t flip any electrical switches, and call PG&E from outside at 1-800-743-5000. A gas smell means there’s an active leak, and that has to come first.
No gas smell? A small amount of unburned gas is normal when the pilot has been out. It’s what fuels the initial lighting attempt. The steps below handle this safely.
How to Relight a Gas Tank Water Heater Pilot
The exact steps vary slightly by manufacturer and model, but the process is similar across most standing pilot gas water heaters. Check the label on the unit for manufacturer-specific instructions. Most water heaters have a relighting procedure printed directly on the front.
What you’ll need: A long-reach lighter or fireplace matches. Some units have a built-in piezo igniter (a small button that generates a spark electronically); others require a manual flame.
Step 1: Locate the gas valve and thermostat control
The gas control valve is typically a box-shaped component at the lower front of the unit with a dial or knob. It has three positions: Hot, Pilot, and Off (some models have a separate temperature dial and a mode dial).
Step 2: Turn the dial to “Off.”
Then wait five minutes. This allows any accumulated gas to disperse first. So don’t skip this step.
Step 3: Turn the dial to “Pilot.”
On units with a separate temperature dial, make sure it’s set to a temperature setting rather than off.
Step 4: Access the pilot assembly
The pilot light typically sits at the base of the burner assembly, inside the unit. Many units have a small access panel or opening at the bottom front. Look for the pilot tube leading to the burner area.
Step 5: Press and hold the pilot button (or depress the gas valve knob)
This allows gas to flow to the pilot tube. Otherwise, pressing the gas valve knob in serves the same function on units without a separate pilot button.
Step 6: While holding the button, bring the lighter flame to the pilot tube opening
Hold the lighter at the end of the pilot tube and keep the button pressed. For units with a piezo igniter, press the igniter button repeatedly while holding the pilot button.
Step 7: Continue holding the button for 30–60 seconds after the pilot lights
This is critical. The thermocouple — the safety sensor — needs time to heat up before it will hold the gas valve open on its own. Indeed, releasing the button too early causes the pilot to go out immediately.
Step 8: Release the button slowly and confirm the pilot stays lit
Afterward, look through the access opening to verify the pilot flame is burning. A properly lit pilot should be a steady blue flame, possibly with a small yellow tip.
Step 9: Set the thermostat to your desired temperature
Turn the dial from “Pilot” to your normal setting (120°F is standard). The main burner should ignite within a few minutes. Hot water follows within 30–60 minutes, depending on tank size.
If the Pilot Won’t Light at All
No gas reaching the pilot: Make sure the gas supply valve on the line to the unit is open (parallel to the pipe). Check that other gas appliances in the house are working. If nothing gas-powered works, there may be a service interruption, or the main gas shutoff may be closed.
Pilot tube is blocked: Over time, the small tube carrying gas to the pilot opening can become blocked with debris or mineral deposits. Is gas flowing elsewhere in the house, but the pilot won’t catch? The tube may need inspection and cleaning — a job for a plumber.
Piezo igniter not sparking: If the igniter button clicks but you don’t see a spark at the pilot tube, the igniter may be faulty. You can use a long-reach lighter as a substitute — hold it at the pilot tube while pressing the pilot button.
Wet pilot assembly: In rare cases, condensation inside the unit can dampen the pilot assembly. In that case, allow the area to dry and try again.
If the Pilot Lights But Won’t Stay Lit
This is the more significant situation. Does the pilot light while you hold the button, but go out as soon as you release it? Or stay lit for only a few seconds? Then the thermocouple is the likely culprit.
The thermocouple is a small sensor that sits in the pilot flame. It generates a tiny electrical current that holds the gas valve open while the pilot is burning. A weak, failing, or badly positioned thermocouple doesn’t generate enough current to keep the valve open. So the pilot goes out.
You’ll find full detail in our pilot light troubleshooting guide. It covers thermocouple diagnosis, replacement, and the other causes of a pilot that won’t stay lit.
Why Pilot Lights Go Out in Santa Cruz
Drafts. Coastal wind is a real factor in Santa Cruz. Garages and utility rooms that aren’t tightly sealed can develop enough airflow to occasionally blow out a pilot. Does your pilot go out regularly in an exposed location? Check for gaps or openings where wind can enter.
Thermocouple wear. The most common cause of a pilot that goes out repeatedly. After all, thermocouples have a limited lifespan and wear out over years of normal use.
Gas supply fluctuation. Temporary drops in gas pressure can extinguish a pilot, particularly in older supply lines. If the pilot goes out occasionally without any draft and relights normally, intermittent pressure issues are worth investigating.
Dirty pilot orifice. Mineral deposits or debris partially blocking the pilot orifice produce a weak flame that doesn’t adequately heat the thermocouple. A plumber can clean or replace the orifice.
Electronic Ignition vs. Standing Pilot
Newer gas water heaters use electronic ignition rather than a standing pilot. The burner ignites automatically on demand, without maintaining a continuous pilot flame. Does your unit lack a pilot access panel, with instructions that reference electronic or spark ignition? Then this guide doesn’t apply. Issues with electronic ignition systems typically involve the igniter module, gas valve, or control board. They require a plumber or technician.
Water Heater Service in Santa Cruz
Relighting didn’t resolve the issue, or the pilot keeps going out? Eco-Flow Plumbing Inc. handles water heater repair and service throughout Santa Cruz County. We serve Santa Cruz, Live Oak, Aptos, Capitola, Soquel, Scotts Valley, Seabright, Felton, Boulder Creek, and Watsonville.
Contact Eco-Flow Plumbing to schedule service. Or call directly: (831) 818-6331.
