No Cool or No Heat: What to Check Before You Call
When the house is too hot or too cold, a few safe checks — thermostat settings, breakers, disconnects, and filters — solve a surprising number of emergencies without a service call. Anything involving gas smell, CO alarms, burning odors, water leaks near equipment, or repeated breaker trips is stop-and-call territory immediately. In Indianapolis peak weather, calling early beats waiting until every board is full — but knowing safe owner checks saves unnecessary dispatches too. LCS triages safety first on emergency calls — gas, CO, and electrical hazards before comfort parts — because guessing on combustion or repeated breaker trips is never worth the risk.
Quick answer
When the house is too hot or too cold, a few safe checks — thermostat settings, breakers, disconnects, and filters — solve a surprising number of emergencies without a service call. Anything involving gas smell, CO alarms, burning odors, water leaks near equipment, or repeated breaker trips is stop-and-call territory immediately. In Indianapolis peak weather, calling early beats waiting until every board is full — but knowing safe owner checks saves unnecessary dispatches too. LCS triages safety first on emergency calls — gas, CO, and electrical hazards before comfort parts — because guessing on combustion or repeated breaker trips is never worth the risk.
- Verify thermostat mode, setpoint, and batteries if applicable.
- Check furnace/air-handler breaker and outdoor disconnect.
- Replace a severely clogged filter — then restore power.
- Gas odor, CO alarm, or burning smell → prioritize safety and professional help.
Peak season failures
First heat wave and first hard freeze create the most no-cool and no-heat calls in Central Indiana. A five-minute checklist can save an unnecessary dispatch — or confirm you truly need professional help before the house becomes unsafe or unbearable when wait times stretch to days. Document what you are seeing — photos, thermostat settings, and prior repair dates — so an LCS visit or Free Second Opinion starts with facts about your Central Indiana home, not guesses.
Before resetting breakers repeatedly
One tripped breaker might be a power blip; repeated trips signal a serious electrical or mechanical fault. Know the line between a simple owner fix and a problem that needs diagnosis with proper tools — guessing on repeated trips can damage equipment or create fire risk. Document what you are seeing — photos, thermostat settings, and prior repair dates — so an LCS visit or Free Second Opinion starts with facts about your Central Indiana home, not guesses.
How it works
Cooling quick checks
Verify thermostat COOL mode with setpoint below room temp, fan on AUTO, outdoor disconnect on, breaker energized, filter not plugged, and outdoor unit clear of debris. After power restoration, wait a few minutes — compressors have restart delays. Listen for the outdoor fan after the delay; silence often means controls or capacitor, not magic. Document what you are seeing — photos, thermostat settings, and prior repair dates — so an LCS visit or Free Second Opinion starts with facts about your Central Indiana home, not guesses.
Heating quick checks
Verify thermostat HEAT mode with setpoint above room temp, furnace door switch engaged, filter clean, and vents open on returns. Do not bypass safety switches or jump controls. Gas odor or CO alarm means stop immediately — fresh air and professional help, not another ignition attempt. Document what you are seeing — photos, thermostat settings, and prior repair dates — so an LCS visit or Free Second Opinion starts with facts about your Central Indiana home, not guesses.
When to stop and call
Burning smells that persist, visible ice on refrigerant lines while running, water flooding near the air handler, gas odor, CO detector alarm, or breakers that trip again after one reset. Those are not filter problems — they need trained diagnosis. Safety first, comfort second. Document what you are seeing — photos, thermostat settings, and prior repair dates — so an LCS visit or Free Second Opinion starts with facts about your Central Indiana home, not guesses.
What goes wrong when this is ignored
Resetting breakers repeatedly
If a breaker trips again after one reset, stop. That can indicate a serious electrical fault, locked compressor, or shorted motor — not a task for repeated owner resets. Call for diagnosis before damage spreads to the compressor or control board. Document what you are seeing — photos, thermostat settings, and prior repair dates — so an LCS visit or Free Second Opinion starts with facts about your Central Indiana home, not guesses.
Running a frozen AC
A frozen evaporator coil needs the system off and airflow restored — usually starting with filter change and thaw time. Running frozen can damage the compressor and does not fix the underlying cause. Recurring freeze after thaw means service, not more owner resets. Document what you are seeing — photos, thermostat settings, and prior repair dates — so an LCS visit or Free Second Opinion starts with facts about your Central Indiana home, not guesses.
Using ovens or stoves for heat
Never use cooking appliances as space heaters. Use only electric space heaters with tip-over protection and clearances while waiting for service — and only if safe in your home layout. Carbon monoxide and fire risk from improvised heat kill people every winter. Document what you are seeing — photos, thermostat settings, and prior repair dates — so an LCS visit or Free Second Opinion starts with facts about your Central Indiana home, not guesses.
Proof & local validation
- 4.9★ from 1,500+ reviews
- Family-owned in Indianapolis since 2005
- Daikin Comfort Pro dealer
- LCS emergency calls triage safety first — gas, CO, and electrical hazards before comfort parts.
How we build this guidance
- Written for Central Indiana climate and housing realities — humid summers, cold winters, older Indy stock.
- LCS Heating and Cooling Launch Crew — family-owned Indianapolis HVAC since 2005.
- Daikin Comfort Pro dealer; Free Second Opinion when another quote needs a reality check.
Author: Renee Lucas, Co-Owner & Customer Experience Director (Brand Voice Director)
Technical reviewer: Travis Lucas, Co-Owner & Technical Operations Director
Last updated: 2026-07-16
Frequently asked questions
Outdoor unit silent but air handler runs — what now?+
Could be thermostat wiring, failed capacitor, contactor, or control fault. After breaker and filter checks, it is a service call — not a part to guess from the internet without diagnosis. Note whether the indoor fan runs on AUTO vs ON; that detail helps the technician.
Is a frozen coil an emergency?+
Turn the system to fan-only or off to thaw, change the filter, and call if it recurs. Running frozen can damage the compressor. Recurring freeze often means airflow, refrigerant, or low outdoor temp operation issues — not a one-time glitch after a clogged filter. When a quote or checklist leaves gaps, LCS Free Second Opinion compares scope and assumptions apples-to-apples for Indianapolis homeowners.
Should I use space heaters while I wait?+
Only units with tip-over and overheat protection and proper clearances. Never use ovens or stoves for heat. Keep bedroom doors open so heat circulates if using a portable heater safely — and keep heaters away from bedding and curtains. When a quote or checklist leaves gaps, LCS Free Second Opinion compares scope and assumptions apples-to-apples for Indianapolis homeowners.
Why does my heat pump blow cool air in winter?+
Brief cool air during defrost can be normal. Sustained cold rooms after defrost completes need service — not just a higher thermostat setting that triggers expensive strip heat all day. See our defrost cycles guide for normal timing. When a quote or checklist leaves gaps, LCS Free Second Opinion compares scope and assumptions apples-to-apples for Indianapolis homeowners.
How fast can LCS respond in peak season?+
Priority members and early callers fare better when every Indianapolis home hits the same weather at once. That is why spring and fall prep matter — they reduce the chance you are calling on the worst day of the year. See seasonal maintenance for the cadence that prevents emergencies.
Ready for the next step?
When you’re ready to move forward, get an honest second look at another quote — or call the Launch Crew.
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