Why Won't My Patio Heater Stay Lit? (The Real Answer)

You hold the knob down. The pilot lights. You release it after 30 seconds and — nothing. The flame dies immediately. You try again. Same thing. If this sounds familiar, you're not alone. It's the single most common patio heater complaint, and the answer is almost always simpler than people think.

Quick Answer

The most common reason a patio heater won't stay lit is a faulty tilt switch, not the thermocouple — even though most guides tell you the opposite. Here's how to tell the difference in 60 seconds.

The Tilt Switch vs. The Thermocouple

Most troubleshooting guides send you straight to the thermocouple. And yes, a bad thermocouple can cause this problem. But after years of handling parts and repairs for Hampton Bay, Master Forge, and Gardensun heaters, we can tell you: the tilt switch fails far more often.

Here's why it matters: if you replace the thermocouple and the heater still won't stay lit, you've wasted money and time on the wrong part. The 60-second test below tells you exactly which one is bad before you order anything.

The Cross-Wire Test 

This is the fastest way to diagnose the problem:

1. Make sure the gas is off and the heater is cool.
2. Open the access panel (two screws on the heater head).
3. Find the tilt switch — it's a small black plastic assembly with two wire connectors.
4. Unplug both wire connectors from the tilt switch.
5. Cross the two loose wires together (touch them to each other).
6. Now try to light the heater normally.

Heater lights and stays lit → Your tilt switch is bad. Replace it.

Heater still won't stay lit → Your thermocouple is bad. Replace it. (Or get the combo pack — both parts together cost less than a service call.)

→ Shop the Thermocouple & Tilt Switch Pack — Genuine OEM · Free Shipping

Why Does the Tilt Switch Fail?

The tilt switch is a safety device — it cuts the gas supply if the heater tips over, preventing fires. It's a simple mechanical switch: when the heater is upright, a small ball or lever completes a circuit and allows gas flow. Over time, that mechanism wears out, corrodes, or gets stuck — and the heater thinks it's tipped over even when it's standing straight.

This is why the heater lights momentarily when you hold the knob down (you're bypassing the safety circuit by holding it), but shuts off the moment you release it.

What About the Thermocouple?

The thermocouple is a heat sensor that tells the gas valve the pilot flame is lit. If it's faulty, dirty, or positioned too far from the flame, the valve closes — and the heater shuts off.

Common signs it's a thermocouple problem:

• The cross-wire test above didn't fix it
• The pilot flame is weak or yellow (instead of a strong blue)
• The heater shuts off after a few minutes, not immediately

Other Reasons Your Heater Won't Stay Lit

Regulator in Safety Lockout

If you opened the tank valve too fast, the regulator may have tripped into safety lockout mode, restricting gas flow to almost nothing. The fix is a simple reset: turn off the tank, disconnect the regulator, wait 30 seconds, reconnect, and open the tank valve slowly. No parts needed.

Low Gas / Near-Empty Tank

When a propane tank gets below about 20% full, especially in cold weather, pressure drops enough to cause ignition problems. Try a fresh tank before replacing any parts.

Dirty Pilot Orifice

Dust, debris, and spider webs love to nest in pilot orifices over winter storage. A can of compressed air usually clears it out.

What Heater Models Does This Apply To?

This applies to virtually all propane-fueled tall, pyramid, and tabletop patio heaters, including:

• Hampton Bay NCZH-G-SS and all NCZH variants (Home Depot)
• Master Forge patio heaters (Lowe's)
• Gardensun patio heaters (direct)
• Fire Sense, Hiland, and most other tall/mushroom-style propane heaters

All of these heaters use the same fundamental gas control system — tilt switch, thermocouple, regulator — which is why the same diagnostic approach works across brands.

Still Not Sure What You Need?

Check our full Patio Heater Troubleshooting Guide — it covers every common issue with step-by-step fixes. Or email us with your heater model and we'll tell you exactly which part to order.