When a gas oven will not heat but the cooktop burners light normally, the problem is almost always inside the oven's own ignition system. In our experience across Rochester, the bake igniter is the culprit more often than every other part combined. What confuses most people is that the igniter still glows. It looks like it is working, yet the oven never lights.
This guide explains why that happens, the signs of a weak igniter, the other parts that can stop a gas oven from heating and what a repair visit involves.
Quick answer: why won't my gas oven heat?
Most gas ovens use a hot surface glow bar igniter wired in series with the gas safety valve. The valve only opens when the igniter draws enough current. Aging igniters glow but draw too little current, so the valve stays shut and no gas flows. Replacing the igniter fixes most no heat calls. Less often, the gas safety valve, temperature sensor, control relay or a closed gas supply is the cause.
How a glow bar igniter controls the gas
When you set the oven to bake, the control sends power through the igniter and the safety valve in the same circuit. The igniter heats up and its resistance drops, letting more current flow. The safety valve contains a small bimetal element that opens only when current reaches a set level, typically around 3 amps on many models. Once open, gas flows past the red hot igniter and lights. This design is a safety feature: gas cannot flow unless the igniter is hot enough to light it.
As igniters age, their resistance rises. They still glow orange, sometimes brightly, but the current never reaches the level the valve needs. The oven sits there with a glowing igniter and no flame, or the valve opens late and the oven lights with a small whoosh.
Signs of a weak igniter
- The igniter glows but there is no flame after 90 seconds
- Preheating takes much longer than it used to
- The oven lights with a noticeable whoosh or pop
- A brief gas smell before the flame appears
- Bake does not work but broil does, or the reverse, on ovens with two igniters
- The oven heats sometimes and not others
Other causes of a gas oven not heating
| Part | Symptom | How it is confirmed |
|---|---|---|
| Gas safety valve | Igniter tests strong but no gas flows | Current draw and valve continuity test |
| Temperature sensor | Oven heats wrong, overshoots or shows an error code | Resistance test at room temperature |
| Control board relay | No glow at the igniter at all | Voltage test at the igniter circuit |
| Closed gas shutoff | Cooktop burners also will not light | Check the valve behind the range |
| Propane setup issue | Weak, yellow or lifting flames | Check orifices and regulator for propane |
| Wiring or terminal | Intermittent heating | Inspect for burned connectors |
What you can check safely
- 1
Confirm the gas supply
If the cooktop burners light, gas is reaching the range.
- 2
Check the power
The clock and display should be on. Gas ranges still need electricity for the igniter.
- 3
Watch the igniter
Remove the oven floor panel if your model allows and watch through the opening. Note how long it glows before any flame.
- 4
Try broil
If broil lights but bake does not on a two igniter oven, the bake igniter is the likely failure.
- 5
Check for error codes
Write down any code on the display for the technician.
Do not remove gas lines, bypass the safety valve or replace parts on a gas appliance unless you are trained to. A misconnected gas part is a fire and carbon monoxide risk.
What happens on a repair visit
We measure the igniter's current draw with an ammeter while the oven calls for heat and compare it with the valve's requirement. If it is low, the igniter is replaced. We then check for gas leaks with a detector, run a full bake cycle, verify the oven reaches and holds temperature with a separate thermometer and check the broil burner too. Igniters for common brands like Whirlpool, GE, Frigidaire, Samsung and LG are usually on the truck, so most of these repairs finish in one visit.
How long igniters last
Glow bar igniters typically last three to five years of regular use. Heavy use, frequent self clean cycles and power surges shorten that. If your oven is older and the igniter has been replaced before, expect to replace it again eventually; it is a wear part, not a sign the oven is failing.
Electric oven instead?
Electric ovens use a bake element and a temperature sensor instead of an igniter and valve. A failed element or sensor is more likely, as in our GE Spectra oven repair in Kutzky Park. For burner problems on the cooktop, see cooktop and range repair.
Bake and broil igniters, and propane ranges
Many gas ranges have two igniters: one for the bake burner under the oven floor and one for the broil burner at the top. They wear independently, so it is common for broil to work while bake does not. Some brands use a single burner for both. Your model number, on a label behind the storage drawer or on the oven frame, tells the technician which igniter to bring.
Homes around Oronoco, Kasson and other rural areas often cook on propane. A propane range must have the correct orifices and regulator setting. If it was never converted, or was converted incorrectly, the oven may light poorly, burn with yellow flames or take very long to heat, which can look like an igniter problem. We check the fuel setup on every propane range visit.
Oven heats but temperature is wrong
If the oven does light but bakes unevenly or runs 25°F or more off the set temperature, the temperature sensor or the control calibration is the more likely cause than the igniter. Test it with an oven thermometer on the center rack after a 20 minute preheat.
Book same day oven repair in Rochester if your oven will not heat.
Common questions
How long does an oven igniter last?
Typically three to five years of regular use, sometimes longer.
Can I use the cooktop if the oven will not light?
Yes, if the cooktop burners light normally and there is no gas smell. The oven igniter is a separate circuit.
Why does my oven igniter glow but not light?
The igniter is too weak to draw the current the safety valve needs to open. It needs replacing.
Does self clean damage the igniter?
The very high heat of self clean can shorten igniter life and expose weak parts. Run it well before you need the oven for something important.
Why does broil work but bake does not?
On ovens with separate bake and broil burners, each has its own igniter. The bake igniter has likely weakened.
