INDIANAPOLIS GUIDE

What you can check, and what to leave alone

The screwdriver is already in your hand and the furnace door is still on, which is the right order. Some heating and cooling problems really are a filter, a thermostat battery, or a switch that got bumped while someone carried laundry. Some are a gas valve, a heat exchanger, or a sealed refrigerant circuit, and those are not practice. This page draws that line for a house in Indianapolis, whether the equipment is in a basement or in a hall closet. It will not walk you through opening a burner box.

By Mike Maziarz · Sources checked October 6, 2026 · How we write these guides

Jobs that stay on your side of the panel

Replace the filter when you can slide it out without tools and you have the size that matches the slot. Write the date on the frame. If the old filter was collapsed or the wrong size, say so later. A clean filter is maintenance. It is not a diagnosis, and it does not authorize you to run the system with the slot empty.

Replace thermostat batteries if the cover says it uses them. Set the mode and the setpoint so the system is actually being asked to heat or cool. Turn the fan back to auto if it was left on and the house feels strange. Flip a furnace switch that is obviously off, once. Look at a tripped breaker, once. If it trips again, leave it off.

Outside, lift leaves and loose debris off the top of the outdoor unit. Do not stab the fins. Do not spray a pressure washer. In winter, clear snow you can reach from the ground around a heat pump or a sidewall vent. Then stop. The cabinet stays closed.

Jobs that are not homeowner repairs

Do not add refrigerant. Do not buy a can and hook it to a port. The sealed system is restricted work under federal rules for certified technicians. The refrigerant guide is the short version. A low charge is a leak conversation, not a top-off you perform in the side yard.

Do not open the burner compartment, adjust a gas valve, or light a pilot if you smell gas or you are unsure. Do not jump out a rollout switch, a pressure switch, or a door switch, and do not tape one closed so the blower will run. Those switches are why the machine stopped. Bypassing them is how a bad day becomes a fire or a carbon monoxide problem.

Do not take the blower apart, oil a motor that is not built to be oiled, or cut into ducts to look. Do not work inside the electrical panel beyond the single look at the breaker already mentioned. If the repair needs a meter on a live board, it needs a technician.

Fuel and carbon monoxide are not practice

A gas smell ends the project. Leave the building, do not flip switches, and from outside call the emergency number on the gas bill. Many Indianapolis addresses use Citizens Energy Group, and the number is the one printed for your account. You do not air the house out as a first step if the smell is strong, and you do not go back to finish a filter change.

A carbon monoxide alarm, or headache, dizziness, or flu-like symptoms that ease outdoors, ends the project the same way. Everyone goes outside. Emergency services get the call. You do not hunt for the source with the door off the furnace. The carbon monoxide page is the sequence, including why a detector that lives only on the furnace is not enough.

Testing the alarm button on a calm day is yours. Replacing an alarm that is past the date on its back is yours. Investigating why it alarmed is not.

Information you can gather without tools

Before you call, write the sounds, the thermostat readings, and whether the outdoor fan is turning. Photograph the data plate with the panel on. Note ice, water in a pan, or a vent buried in snow. That packet is the useful kind of do-it-yourself. It does not require a single fastener to come out.

The overview of a visit is the longer version of those notes, including how a basement utility closet differs from an attic air handler. Bring the notes. Do not bring a theory you proved by bypassing a control.

If you already replaced the filter and set the thermostat and the system still fails, you have finished the homeowner list. Another hour with a flashlight inside the cabinet rarely adds a fact a technician can trust. It can add a damaged wire.

Saving the visit is not a reason to cross the line

People cross the line because they hope to avoid a service call. The things that change a quote, access, timing, parts, permits, are real, and the cost factors page lists them without prices. None of those factors make a gas valve or a refrigerant port into a homeowner fitting.

A wrong repair is not free. A burned board, a compressor that ran without charge, or a furnace left in a bypassed state costs the next visit its simplicity. Ask for a written finding instead. You can decline the repair. You cannot decline the physics.

If a video shows a person jumping a wire and the comments say it worked, that is not a local rule and not a safe procedure. Your house has the switches it has. Leave them in the circuit.

When the call is the whole job

Call when there is no heat and the house is getting cold, when cooling will not catch up in humid weather, when you see ice on the line after a fresh filter, when water is overflowing a pan, or when a breaker will not stay on. Call when you smell burning. Call when you are simply unsure. Unsure is a complete reason.

Tell the company what you already did: new filter, new batteries, switch checked once. Tell them what you did not do. A technician who knows the door never came off will trust the rest of the story.

Keep the homeowner list short on purpose. Filter, batteries, mode, one switch, debris you can lift, alarm test, notes. Everything past that is the visit. The line is there so a Saturday project does not become the reason the house is unsafe on Saturday night.