Furnace / Heat Won't Start repair in Orlando, FL

Verified against official sources · Updated 2026-07-06

Thinking about a furnace / heat won't start repair in the Orlando area? Here's what actually matters — permit rules for Orange County and the City of Orlando, plus the mistakes and code requirements that trip up homeowners, sourced from manufacturer manuals and the Florida Building Code.

Do you need a permit?

Permit required. Mechanical permit for ALL permanently installed AC/heating equipment, including like-for-like changeouts; plug-in window/portable units exempt.
Source: https://www.orangecountyfl.net/PermitsLicenses/Permits/MechanicalPermit.aspx

Key facts before you start

Order: thermostat first — mode=HEAT (fan on AUTO not ON), setpoint several degrees above room temp, replace thermostat batteries; then the furnace/air-handler power switch (looks like a light switch on or near the unit) and the breaker — reset fully OFF then ON.
Heat pumps (the FL default): indoor and outdoor units are on SEPARATE breakers (outdoor typically 240V) — check both. If it cools fine but won't heat, suspect a stuck reversing valve = pro. 'Em Heat' just runs electric strips as a bypass for a dead heat pump — OK temporarily, spikes the bill, and means service is needed.
A steam cloud off the outdoor unit plus 'AUX heat' on the thermostat for ~3–15 min is a NORMAL defrost cycle, not a failure. Constant defrost cycling or ice covering the cabinet = call a pro.
Gas furnace totally dead after power checks: reseat the blower door — the door interlock switch cuts all power and gas whenever the panel isn't fully engaged. Then read the status LED through the door window: count the red flash pattern and match it to the fault-code legend printed on the door panel; record it before calling.
Burners light then die in seconds, locking out after 3 retries (e.g., Goodman E0): an invisible insulating coating on the flame sensor is the most common no-heat cause. Fix = gently clean the sensor rod with fine steel wool/emery (power AND gas off first; Goodman rates this qualified-servicer work). Recurs after cleaning = replace sensor/call pro.
90%+ condensing furnace blowing cold: a clogged condensate drain/trap trips a safety that blocks burner ignition — clear/flush the drain before suspecting ignition parts. HARD STOPS: rotten-egg smell = leave the house immediately and call the gas company from outside (touch no switches, no relight attempts); repeated lockouts after a single reset = pro.

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Sources

https://www.carrier.com/us/en/residential/hvac-resources/furnaces/furnace-not-turning-on/
https://www.trane.com/residential/en/resources/troubleshooting/gas-furnaces/furnace-not-turning-on/
https://www.carrier.com/residential/en/us/products/heat-pumps/heat-pump-not-heating/
https://www.trane.com/residential/en/resources/blog/what-is-heat-pump-defrost-cycle/
https://www.trane.com/residential/en/resources/troubleshooting/gas-furnaces/furnace-light-blinking/
https://www.trane.com/residential/en/resources/troubleshooting/gas-furnaces/furnace-not-blowing-not-air/
https://mobile.goodmanmfg.com/mobileapp/stellent/pdf/infoPdf/Lit/RS6621008R2.pdf

This guide is general informational content, not professional or legal advice. Codes and county rules change — confirm permit requirements with your local building department, and use a licensed professional for electrical, gas, structural, or main-line plumbing work.