Patio Heater Won’t Stay Lit? | Quick Fix Guide

Nothing kills a chilly-evening hangout like a flame that keeps cutting out. This guide gives you clear checks in the right order, from easy wins to deeper fixes. You’ll also see safe limits and when to stop and swap parts.

Fast Checks Before You Grab Tools

Start with simple causes. These take minutes and solve many cut-out cases.

• Confirm the cylinder valve is open and the tank has fuel.
• Open the tank valve slowly to avoid tripping the excess-flow feature.
• Shield the base from gusts; wind can blow the pilot off the sensor.
• Hold the control knob in the pilot position long enough for the flame sensor to heat.

Outdoor Heater Won’t Stay Lit — Causes And Fixes

The table below maps the most common failure points to what you’ll see and the first test to try.

Cause	What You See	Quick Test
Thermocouple not sensing	Pilot lights but drops when you release the knob	Hold knob longer; check flame touching probe
Dirty pilot orifice	Weak, tiny, or yellow pilot flame	Blast with compressed air; clean tip gently
Excess-flow in regulator tripped	Pilot lights briefly, main burner starves	Reset regulator; open tank valve slowly
Loose pilot tubing or fittings	Pilot flickers; occasional sputter	Tighten fittings; leak-check with soapy water
Tilt switch opening	Flame cuts when the head is bumped or leaned	Set unit level; inspect the tip-over switch
Low vapor from cold or near-empty tank	Burner fades in cold weather	Warm the cylinder gently; swap for a full tank

How The Safety Chain Keeps Gas Flowing

Most tower units use a simple chain: pilot flame heats a thermocouple, which sends a small current to the gas valve so it stays open. If the flame goes out, the valve shuts. A tilt switch in series adds tip-over protection. When any link opens, the main burner drops out.

Thermocouple Basics In Plain Terms

The probe sits in the pilot flame. Heat creates a tiny millivolt signal across two metals. That signal holds the safety valve open. If the probe is dirty, misaligned, cracked, or too cool, the signal drops and the flame dies.

Troubleshooting Steps That Work

1) Reset The Regulator Bypass

Many propane setups include an excess-flow feature that limits gas after a sudden rush. If you opened the tank fast, it can trip and starve the burner. Close the tank, turn the control knob to OFF, disconnect the regulator for a minute, reconnect, then reopen the tank slowly. This feature relates to the OPD valve on modern cylinders; the OPD FAQ explains the safety device and its role.

2) Clean And Aim The Pilot

Dust, spider webs, and carbon narrow the pilot jet. Remove the emitter screen if needed. Blow the pilot tube with compressed air. Use a soft brush on the tip. Relight and check that the blue pilot wraps the probe tip by 1/4–3/8 inch. Bend the bracket slightly so the flame hits the hottest point of the sensor.

3) Warm Or Swap The Cylinder

On cold nights or when the tank is low, propane boils off slower. Vapor supply drops and the burner fades. Keep the bottle off cold concrete, out of wind, and above the minimum fill. If the flame still sags, swap in a fuller cylinder.

4) Check The Tilt Switch

Look for a small silver or black switch in the control box. It usually has two spade terminals and a rolling bead inside. With the heater upright, the switch should read closed on a meter. If it opens randomly, replace it with the same rating.

5) Test The Thermocouple Output

With the pilot lit, disconnect the probe from the gas valve and read millivolts across the lead and sheath. Many valves need around 20–30 mV to hold. If you see much less and the flame is healthy, the probe may be tired. Replace it with a matched length and thread.

Fuel Supply And Cold Weather Reality

Cylinders deliver less vapor as temperature and fill level drop. A 20-pound bottle that feeds a grill fine at noon can stumble at night when the air and liquid cool down. Keep a spare tank on hand for cold snaps and avoid running bottles to near empty. If frost builds on the regulator, move the tank where it’s sheltered and dry.

Model Manuals And Specs To Check

Many makers include a simple fault table that points right to the culprit. A sample manual lists dirt around the pilot, a loose connection between the valve and pilot, and a weak thermocouple as top causes. Keep the PDF for your unit and match parts by model number. If you need a reference, this owner’s manual fault table shows the typical layout.

Safe Lighting Routine That Avoids Trips

1. Place the unit on level ground with clear space above.
2. Attach the regulator snugly; do not use tools on hand-tight fittings.
3. Close the control knob and the tank valve. Wait one minute.
4. Open the tank valve slowly.
5. Press and hold the knob to the pilot position and spark the igniter.
6. Keep holding the knob for 30–60 seconds so the probe heats.
7. Release and turn to ON. If the flame drops, repeat and aim the pilot.

When The Main Burner Won’t Join The Party

If the pilot stays on yet the top never roars, the issue sits past the safety chain. Check the orifice and the screen under the emitter head. Spiders love that space. Soak the tiny brass orifice in alcohol, then blow it dry. Confirm the control knob is turned to ON, not stuck in a detent between pilot and full flow. If the head glows dull red but never lifts off, suspect low vapor from the tank or a regulator that needs a reset.

Care And Maintenance That Prevents Dropouts

• Vacuum the base and burner head each season.
• Check all joints with soapy water after service.
• Replace igniter batteries before cold weather.
• Keep spare parts on hand: probe, igniter, and a tilt switch.
• Store cylinders upright, valve caps on, away from heat.

Rules, Safety, And When To Stop

These heaters are for outdoor use with clear airflow. Never pull one into a tent, garage, or enclosed patio. If anyone feels dizzy or sick, shut the valve and move to fresh air. Use a CO alarm indoors near sleeping areas so you catch trouble early. The CO detector guidance explains placement and UL 2034 labeling.

Cold Weather Myths And Facts

Frost on the outside of a bottle does not always mean the tank is empty. It often marks the liquid level and heavy draw. If the heater cycles off and the regulator looks iced, water inside the regulator can also freeze. Dry fuel and a sheltered spot cut that risk. Do not blast the regulator with a flame; move air across it and let it thaw on its own.

Another winter hiccup comes from long, thin hoses. A narrow line adds drop in pressure, which can make the burner lazy in a cold draw. Keep the hose run as short as the manual allows and avoid tight loops.

Model Differences That Affect Flame Hold

Some units ship set for one gas only. A head or valve made for natural gas will not behave the same on propane. If your heater came second-hand, check the rating plate and the orifice size. A mismatch can lead to a weak pilot and a burner that never reaches a steady roar.

Close Variations Of The Core Problem — And Fix Paths

Searches vary from “outdoor heater keeps shutting off” to “pilot light drops out” and “tower burner won’t stay on.” The root causes stay the same. Use the table below to match your wording to a fix plan.

Symptom Phrase	Likely Cause	First Fix To Try
Outdoor heater keeps shutting off	Pilot not heating the sensor	Clean and aim pilot; hold knob longer
Patio flame cuts out in wind	Pilot blown off the probe	Wind shield at base; re-aim pilot
Pilot steady, top never roars	Orifice clogged or flow limited	Clean orifice; reset regulator
Works for 10 minutes, then fades	Low vapor from cold or low tank	Swap for a fuller cylinder
Dies when bumped	Tilt switch sensitive or loose	Secure or replace switch

Parts You May Replace

Thermocouple

Pick a probe with the same length and thread. If the bracket is slotted, you can fine-tune the tip so the blue pilot wraps it. Do not over-tighten the compression nut; snug is plenty.

Pilot Assembly

If the jet is damaged or the flame stays weak after cleaning, swap the whole assembly. Take a photo before you pull tubing so you match routing later.

Igniter

Many units use a push-button spark module. If it clicks but never lights, check the ground wire and the gap first. Replace the module only after the pilot jet is clean.

Regulator And Hose

Cracked hoses or a regulator that freezes and dumps pressure need replacement. Choose a unit with the same outlet pressure rating as the original.

Smart Usage Tips For Fewer Callbacks

• Open the tank valve slowly every time.
• Keep a spare cylinder so you never run into low-vapor stalls.
• Sweep for webs before the season starts.
• Level the base; a lean can upset the tilt switch.
• Log a quick start-up checklist and hand it to guests who use the deck heater.

When Professional Service Makes Sense

If leak tests fail, if you smell gas you can’t locate, or if the gas valve body is damaged, stop and call a licensed tech. That step protects the house and the people on the patio. Keep the manual for your exact model, since wiring and parts layouts vary.