Every modern oven runs a feedback loop, and understanding it tells you exactly where to look. The control board energizes the heat source — the bake element on electric, or the igniter and gas valve on gas. The oven warms, and a temperature sensor (an RTD probe near the back of the cavity) reports the rising temperature back to the board. When the target is reached, the board cuts the heat; when the temperature drifts below target by about 10–15°F, it re-energizes. That cycling is why a working oven swings slightly above and below the set point and averages out to the right temperature over time.

Break any link in that loop and you get a specific symptom. A dead heat source means no heat at all. A degraded heat source means the oven heats but never reaches target. A bad sensor means the board is flying blind and either refuses to heat or wildly overshoots. Lost calibration means every part works but the board’s idea of “350°F” is off. Matching your symptom to the link is the whole diagnosis.

On a gas oven the igniter (also called a glow bar) does two jobs: it draws current through the oven’s safety valve to open it, and it glows hot enough to light the gas. As it ages it weakens, and a weak igniter can still glow brightly while no longer pulling enough current to open the valve — so you see it glowing, but no flame ever appears. The field rule is precise: if the igniter glows for more than 90 seconds without lighting the burner, it’s too weak and must be replaced. If it doesn’t glow at all, test it for continuity — no continuity means it’s dead.

A common Frigidaire/Electrolux igniter is part 5303935066, around $30–$50. A healthy igniter reads roughly 75Ω on a multimeter’s 200-ohm setting; a burned-out one shows no reading. This is the most frequent gas-side repair and it restores heat in minutes once the part is in.

On an electric oven the bake element is the U-shaped tube across the bottom. When it fails it usually shows it — a blistered spot, a burn-through hole, or a crack exposing the white insulation. Run a bake cycle and watch through the door: a healthy element glows a uniform bright orange. If only part of it glows, or it glows dim and uneven, the element is partially shorted or degraded — it’ll heat the oven but never get it to temperature because its wattage has dropped.

Confirm with a meter. With power off and one wire disconnected, measure resistance across the element terminals.

The RTD is a thin metal probe at the back of the cavity, held by two screws. It’s a 1K-ohm-class resistor whose resistance climbs predictably as it heats, and the board reads it to regulate temperature. When it fails, the oven either refuses to heat (board sees an open circuit) or overshoots and stalls (board gets bad data). It’s the cheapest of the major parts and a frequent cause of temperature being off without any element or igniter fault.

The sensor follows a known curve, which makes it testable cold:

Measure across the two pins with the probe at room temperature; if it’s not near 1080–1100Ω, or the reading jumps when you wiggle the lead, replace it. The RTD part runs about $20–$60.

If the oven heats fine but everything bakes too dark or too pale, and the meter says the element, igniter, and sensor are all good, the problem is calibration drift. Most ovens let you offset the displayed temperature, usually by 35°F in either direction, through the bake-and-hold or settings menu. The honest way to find the offset is an oven thermometer: set 350°F, let it fully cycle, read the actual temperature, and adjust the offset to close the gap. This is a no-parts fix and explains a surprising share of “my oven runs hot” complaints that aren’t failures at all.

On an electric oven, the heating elements need both 120V legs of the 240V supply, but the clock and controls run on just one. So a half-tripped double breaker leaves the display fully lit while the oven can’t heat at all. This is one of the most common “no heat” service calls, and it’s worth checking before anything else: don’t assume the breaker is on just because the panel glows. Flip the oven’s double breaker fully off and back on. If that restores heat, it cost nothing.

These include our $99 service call applied to the repair.

If your oven won’t reach temperature and you’d rather not run live electrical tests yourself, Neighborville’s technicians measure the element, igniter, and sensor on the first visit and tell you exactly which one failed, across all our service areas. The same crews handle the related cooking problems that show up alongside heat faults — see our guides on a gas burner that won’t light and an oven that won’t heat, both of which can share an igniter or control fault.