Fillable checklist

HVAC Maintenance Checklist: Indoor Air Handler and Outdoor Condenser (Free Printable PDF)

Fillable split-system HVAC maintenance form: filter, coils, drain, thermostat, and a dated service log. Print blank or save a filled PDF.

Maintenance Fillable form · 8 sections · 37 checks Download filled or blank PDF and CSV Cross-checked against ENERGY STAR, Carrier, Trane, and DOE · Last verified Sep 1, 2026

Snugage fillable checklist

Fill this on screen, then download a PDF or CSV. Download a blank copy to complete by hand. Answers stay in this tab only. The next visitor sees a blank form. This is owner and technician periodic maintenance for a US home split system (indoor air handler or furnace plus outdoor condenser). It is not a full home inspection and not a licensed HVAC exam. Follow the OEM manual for the equipment on site.

  • 8 sections
  • 37 checks
  • Blank for each visitor

Form details

System and service date

Record the split system that is actually installed. Mark gas-furnace lines N/A when there is no gas burner. Mark heat-pump lines N/A when the outdoor unit is cooling-only. This is a maintenance template, not a substitute for the OEM procedure or a licensed HVAC technician.

13 fields
System and service date

Basement, closet, attic, garage, crawl space, or other.

Air handler or furnace rating plate.

Condenser or heat pump rating plate.

As printed on the frame, for example 16x25x1. Match type and size on replacement (Lennox, Goodman).

Record the thermostat cooling setting. This is not a pass or fail limit.

Record the thermostat heating setting. This is not a pass or fail limit.

Owner, technician name, or company.

Inspection station

Indoor filter and registers

Do these indoor airflow lines first. Skip a line only when it is not due this visit. Mark N/A only if that part is not installed. Outdoor coil and clearance stay in the outdoor section.

5 items
Indoor filter and registers

Filter inspected, cleaned, or replaced

ENERGY STAR and DOE Energy Saver: check the filter every month, especially in winter and summer, and change it when dirty, at a minimum every 3 months. Carrier: typically every 1 to 3 months. Trane: check monthly; 1-inch filters often need a monthly change; thicker media may last longer. Goodman: at least once a month. Never run the system with no filter (Goodman).

Filter inspected, cleaned, or replaced: Done, Skip, or N/A

Replacement matches size and type, door closed

Lennox and Goodman: replace a disposable filter with the same type and size. Seat it fully so air cannot bypass the media. Close the filter door or grille. The filter and all access panels must be in place whenever the unit runs.

Replacement matches size and type, door closed: Done, Skip, or N/A

Airflow arrow toward the blower

Trane: insert the new filter with the arrow pointing toward the furnace or air handler (the direction of airflow). Turn the system off before you pull the old filter so unfiltered air does not enter the cabinet.

Airflow arrow toward the blower: Done, Skip, or N/A

Supply and return registers unobstructed

Trane and Carrier: move furniture, drapes, and rugs off supply registers and return grilles. DOE Energy Saver: keep warm-air registers unblocked. Restricted returns starve the blower and can freeze an indoor coil in cooling.

Supply and return registers unobstructed: Done, Skip, or N/A

Indoor cabinet area kept clear

Trane: do not use the furnace or air handler as storage. Keep combustible materials away from a gas furnace. Leave working space so the filter and drain can be reached.

Indoor cabinet area kept clear: Done, Skip, or N/A

Inspection station

Indoor coil, condensate, and blower

These lines are the indoor evaporator, drain, and blower only. Do not repeat outdoor coil or outdoor clearance here. Mark auxiliary-drain lines N/A when no secondary pan or switch is installed.

7 items
Indoor coil, condensate, and blower

Indoor evaporator coil inspected or cleaned

ENERGY STAR: dirty evaporator coils reduce cooling and make the system run longer. Carrier and Trane treat a deep indoor-coil clean as a technician task; a homeowner visual is for dust, frost, or mold on accessible faces. A frozen indoor coil in summer often traces to a dirty filter or low refrigerant. Call a licensed technician for chemical cleaning or a sealed-system check.

Indoor evaporator coil inspected or cleaned: Done, Skip, or N/A

Primary drain pan clear, no standing water

Lennox: condensate collects in the pan under the indoor coil and should leave through the drain line. Standing water, rust, or overflow is a clog or a failed trap. Clean the pan if you can reach it with power off. ENERGY STAR: a plugged drain can cause water damage and raise indoor humidity.

Primary drain pan clear, no standing water: Done, Skip, or N/A

Primary condensate drain checked or flushed

Lennox: check the indoor drain (and an auxiliary drain, if installed) for obstructions. Their service page: flush every few months; vinegar or an approved PVC cleaner, sit, then rinse. Goodman: on a hot day a working line often shows a steady drip at the outdoor termination. Turn power off before you open a clean-out. Recurring clogs, mold odor, or flooding need a technician.

Primary condensate drain checked or flushed: Done, Skip, or N/A

Auxiliary drain, secondary pan, or overflow switch

Lennox: many indoor units have a secondary pan and a backup drain that may dump above a door or window, plus a float switch that shuts the system down. Confirm the backup path is open and the switch is not tripped. Mark N/A when no secondary pan or switch is installed.

Auxiliary drain, secondary pan, or overflow switch: Done, Skip, or N/A

Blower wheel, housing, and motor inspected

ENERGY STAR: clean and adjust blower components; airflow problems can cut efficiency by up to 15 percent. Carrier and Trane list blower inspection and cleaning on a professional visit. A homeowner visual is for obvious dust on an accessible wheel. Do not oil a motor the OEM calls permanently lubricated (Goodman).

Blower wheel, housing, and motor inspected: Done, Skip, or N/A

Access panels and filter door in place

Lennox and Goodman: the filter and all access panels must be in place any time the unit operates. A missing panel dumps unfiltered air onto the coil and can change airflow across the heat exchanger or evaporator.

Access panels and filter door in place: Done, Skip, or N/A

No unexplained water at the indoor unit

Trane: puddles at the indoor unit can mean a clogged condensate line, a frozen evaporator, or another fault. Lennox: pooling, rust, or high indoor humidity are clog signs. Stop and call a technician if water has reached electrical parts.

No unexplained water at the indoor unit: Done, Skip, or N/A

Inspection station

Outdoor condenser coil and clearances

These lines are the outdoor cabinet only. Indoor coil, indoor drain flush, and filter stay in the indoor sections. Mark N/A if this property has no outdoor condenser (for example a packaged rooftop you are not servicing here).

8 items
Outdoor condenser coil and clearances

Vegetation and objects kept off the outdoor unit

Carrier: keep at least 2 feet of clearance and rinse gently. Trane: at least 2 feet on all sides and 4 feet above (do not build a deck over the unit); plants at least a 2-foot radius. Goodman and Lennox: trim foliage and remove grass, leaves, and debris. OEM install side clearances can be smaller than those homeowner figures and are model-specific. Use the manual for this unit. This is not a code pass or fail number.

Vegetation and objects kept off the outdoor unit: Done, Skip, or N/A

Leaves, grass, pollen, and papers removed

Lennox: check monthly and pull grass clippings, leaves, or papers off the fins. Trane: clear pollen, twigs, and debris from the top; discharge a mower away from the unit. Carrier: remove leaves at the base. Power off before you reach into the cabinet.

Leaves, grass, pollen, and papers removed: Done, Skip, or N/A

Outdoor coil rinsed or scheduled for a pro clean

Carrier and Trane: with the unit off, a garden hose on a gentle setting can rinse the outdoor coil. Do not use a pressure washer or a jet nozzle. Lennox: professional coil cleaning is preferred at least yearly. Coastal salt may need more frequent washing per the OEM.

Outdoor coil rinsed or scheduled for a pro clean: Done, Skip, or N/A

Fins visually straight, not crushed

Goodman and Trane: bent fins block airflow. Do not comb aluminum fins unless you have the right tool and the OEM allows it. Call a technician for crushed faces or obvious oil stains that may mean a refrigerant leak.

Fins visually straight, not crushed: Done, Skip, or N/A

Outdoor disconnect accessible and on

Lennox preservice check: confirm disconnects are ON and breakers are not tripped before you call for no-cool or no-heat. Know where the outdoor disconnect is before you rinse the coil. Electrical work beyond a visual is a licensed task.

Outdoor disconnect accessible and on: Done, Skip, or N/A

Line-set insulation intact on the suction line

The larger insulated vapor line should still have intact foam from the outdoor unit toward the house. Missing insulation wastes capacity and can sweat. This is a visual only. Refrigerant charging and leak repair need an EPA Section 608 technician.

Line-set insulation intact on the suction line: Done, Skip, or N/A

Unit reasonably level, not buried, snow below louvers

Lennox: keep snow below the louvered panels. Trane: clear heavy snow off a heat pump. Goodman: the outdoor unit should sit on a solid, level base. Do not bury the coil in mulch or soil. Mark Skip if there is no snow and the pad already looks sound.

Unit reasonably level, not buried, snow below louvers: Done, Skip, or N/A

Sprinklers not soaking the outdoor cabinet

Lennox: treated sprinkler or soaker water on the cabinet corrodes steel and aluminum. Redirect spray. Mark N/A if no irrigation reaches the unit.

Sprinklers not soaking the outdoor cabinet: Done, Skip, or N/A

Inspection station

Thermostat and system response

Record setpoints in the header. These lines are the control check only. Heat-pump reversing and defrost stay in the heat-pump section.

4 items
Thermostat and system response

Mode and setpoints match the season

ENERGY STAR: confirm settings keep you comfortable when home and save energy when away. Trane: a furnace that will not start is often still in cool. Carrier: avoid large setpoint swings that short-cycle the equipment. Record the numbers in the header. This form does not invent a pass or fail indoor temperature.

Mode and setpoints match the season: Done, Skip, or N/A

Thermostat batteries replaced if it uses them

Goodman: replace batteries as needed; if there is no low-battery alert, replace them about yearly, often with smoke or CO batteries. Hard-wired thermostats with no backup cell: mark N/A.

Thermostat batteries replaced if it uses them: Done, Skip, or N/A

System starts, runs, and shuts off on a call

ENERGY STAR: check that the equipment starts, operates, and shuts off properly. Trane and Lennox: verify the thermostat setting before you assume a failure. Listen for new rattles or grinding (Carrier) and stop if you smell electrical burning.

System starts, runs, and shuts off on a call: Done, Skip, or N/A

Programmable or smart schedule reviewed

ENERGY STAR: a certified smart thermostat can cut heating and cooling cost when the house is empty. Their certified-homes guide: set cooling a few degrees warmer when you are at work, then recover before you return. DOE Energy Saver: a 7 to 10°F setback for about 8 hours can save on a conventional furnace. On a heat pump, use a heat-pump-aware thermostat so setback does not lock in electric-resistance heat. Mark N/A on a manual thermostat with no schedule.

Programmable or smart schedule reviewed: Done, Skip, or N/A

Inspection station

Gas furnace combustion and vent (if gas)

Complete these lines only when a gas or propane furnace is installed. Mark every line N/A on an electric air handler or a heat pump with no burner. Combustion, gas pressure, and heat-exchanger inspection are licensed work. If you smell gas, leave the house and call the gas supplier from outside.

8 items
Gas furnace combustion and vent (if gas)

Combustibles kept away from the furnace

Trane: keep combustible storage off the furnace. If you smell gas or rotten eggs, do not light appliances, do not switch lights, and do not use a phone inside. Call the gas supplier from a neighbor's yard. Flood-damaged furnaces stay off until a qualified agency inspects them.

Combustibles kept away from the furnace: Done, Skip, or N/A

Combustion-air openings unobstructed

Do not block louvered doors or stuff insulation against burner or intake openings. Trane: condensing-furnace PVC intake and exhaust must stay clear of snow and debris. Mark N/A on electric heat with no burner.

Combustion-air openings unobstructed: Done, Skip, or N/A

Vent, flue, chimney, or PVC exhaust checked

Trane professional list: flue pipe, chimney, and vent connector clear, in place, sloping up, without holes or heavy corrosion; condensing intake and exhaust physically sound. ENERGY STAR: a dirty burner or cracked heat exchanger is a safety issue. A homeowner visual is for disconnected pipe, soot, or a bird nest. Repair is licensed work.

Vent, flue, chimney, or PVC exhaust checked: Done, Skip, or N/A

Burner flame looked at (steady, not sooting)

Trane: look for a steady blue flame. Yellow or orange flicker needs a technician. Do not pull burners or adjust a gas valve yourself. ENERGY STAR lists gas connections, gas pressure, burner combustion, and the heat exchanger as contractor items.

Burner flame looked at (steady, not sooting): Done, Skip, or N/A

Heat exchanger inspected by a licensed technician

Trane: the annual visit includes checking the heat exchanger for cracks, holes, or leaks. A cracked exchanger can leak combustion gases, including carbon monoxide, into the supply air. This is not a homeowner disassembly task. Mark Skip if this visit is owner-only and you will schedule the fall tune-up. Mark N/A if there is no gas furnace.

Heat exchanger inspected by a licensed technician: Done, Skip, or N/A

Manual gas shutoff at the furnace identified

Trane: if there is a fuel or mechanical failure, shut the manual gas valve on the gas pipe before you cut electric power, then call a qualified agency. Know where that valve is before heating season. Mark N/A on electric-only heat.

Manual gas shutoff at the furnace identified: Done, Skip, or N/A

Condensing-furnace condensate drain clear

Trane: high-efficiency (roughly 90 percent AFUE and above) furnaces make condensate and need a clear drain and pan. Mid-efficiency furnaces with a metal flue and no condensate: mark N/A. Do not confuse this drain with the air-conditioner evaporator drain in the indoor section.

Condensing-furnace condensate drain clear: Done, Skip, or N/A

Carbon monoxide alarm present and tested

Trane: install CO detectors per local rules and test them; change batteries when needed. A sounding CO alarm, soot, or a metallic odor with the furnace running is a reason to shut the furnace down and get everyone out until the house is checked. This line does not replace a licensed combustion test.

Carbon monoxide alarm present and tested: Done, Skip, or N/A

Inspection station

Heat pump defrost and reversing (if installed)

Complete these lines on a heat pump or dual-fuel outdoor unit. Mark every line N/A on a cooling-only condenser. Outdoor clearance and a hose rinse stay in the outdoor section so those lines are not duplicated.

5 items
Heat pump defrost and reversing (if installed)

Heating and cooling modes both respond

Carrier: a professional visit checks reversing-valve operation. Homeowner check: set Heat and feel supply air after a few minutes, then Cool when weather allows. Carrier: air that stays cold in heat, after the thermostat is on Heat, can mean a reversing-valve, compressor, or charge problem. Call a technician. Do not force a valve.

Heating and cooling modes both respond: Done, Skip, or N/A

Defrost cycle observed or tested

Carrier: the dealer should test defrost for winter reliability. Lennox: frost on the outdoor coil below about 45°F is expected; a typical defrost lasts 5 to 15 minutes, may show steam, and may bring on auxiliary heat. That is normal. Do not chip ice off the coil. Persistent ice after a completed cycle, or back-to-back defrosts that never clear the coil, need a technician.

Defrost cycle observed or tested: Done, Skip, or N/A

No solid ice left after a completed defrost

Carrier: a unit that stays frozen can point to a failed defrost, low refrigerant, or a blockage, and should not keep running. In summer, a frozen indoor coil is a different problem (filter or charge) and belongs on the indoor-coil line. Light frost that melts on defrost is not a defect.

No solid ice left after a completed defrost: Done, Skip, or N/A

Auxiliary or emergency heat checked

Carrier: check auxiliary heat and heating in defrost. Lennox: the thermostat may call auxiliary heat during defrost, then return to heat-pump heating. DOE Energy Saver: do not set back a heat pump in a way that locks in electric-resistance heat. Confirm Emergency Heat is not left on by accident. Mark N/A if this heat pump has no strip or dual-fuel backup.

Auxiliary or emergency heat checked: Done, Skip, or N/A

Snow and ice kept off the outdoor coil in heating season

Trane and Carrier: keep snow off the top and sides so the outdoor coil can breathe. Lennox: keep snow below the louvers. This is the winter heating check. Year-round plant clearance stays on the outdoor section. Mark Skip in a climate with no snow this season.

Snow and ice kept off the outdoor coil in heating season: Done, Skip, or N/A

Form details

Service log and sign-off

Write what you found and replaced, set the next filter and service dates, then sign. If combustion, refrigerant, or a frozen coil needs a license, pick Licensed technician needed instead of Service complete.

8 fields
Service log and sign-off

ENERGY STAR: check monthly and change at least every 3 months. Shorten the interval with pets, allergies, or heavy seasonal use (Trane).

ENERGY STAR, Carrier, Trane, and Goodman: cooling check in spring, heating check in fall. Heat pumps often need both visits.

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References

  1. Heat and Cool Efficiently - ENERGY STAR / U.S. EPA
  2. Maintenance Checklist for Heating and Cooling Equipment - ENERGY STAR / U.S. EPA
  3. ENERGY STAR Certified Homes Maintenance Guide - ENERGY STAR / U.S. EPA
  4. Energy Saver: Tips on Saving Money and Energy in Your Home (2022) - U.S. Department of Energy
  5. Your Guide To Annual HVAC Maintenance - Carrier Residential
  6. Heat Pump Service and Maintenance Tips - Carrier Residential
  7. HVAC Maintenance Tips and Seasonal Guide - Trane
  8. Central Air Conditioner Maintenance - Trane
  9. Gas Furnace Maintenance Checklist - Trane
  10. Simple Air Conditioner Maintenance Tips - Goodman
  11. Condensing Unit Installation and Service Reference, homeowner routine maintenance - Goodman
  12. What To Do When You Have a Clogged AC Drain Line - Lennox
  13. XP25 Outdoor Heat Pump Homeowner Information and Routine Maintenance - Lennox
  14. ANSI/ACCA 4 QM-2019 (R2024) Maintenance of Residential HVAC Systems - Air Conditioning Contractors of America
  15. ANSI/ASHRAE Standard 62.2-2022 Fact Sheet - ASHRAE

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These checklists are provided for general reference only. Always verify the steps against local codes, a licensed inspector or a qualified contractor before relying on them, especially for safety-critical work.