HomiCrew
A white wall-mounted outdoor heat pump unit with a round fan grille, fixed to dark wood siding.

Photo credit

Photo: Piisamson, “Sanyo SAP-KRV-93EHN”, CC BY-SA 3.0, via Wikimedia Commons. Resized and converted to WebP; shown cropped.

Every photo credit
Can be urgent

Heating & cooling

Furnaces, boilers, heat pumps, air conditioners, ductwork, thermostats.

Is it urgent?

CO alarm or a gas smell? Get everyone outside, then call 911 or your gas utility from outside.

Emergency: call now

Within a day or two

Can wait: schedule it

Show the full list

Safety first: If a carbon monoxide alarm is sounding, or you smell gas (a rotten-egg smell), get everyone outside first, then call 911 or your gas utility's emergency line from outside. Do not flip switches or try to fix it yourself.

Emergency: call now

  • A carbon monoxide alarm, a gas or rotten-egg smell, a burning or electrical smell, or sparks or smoke from a unit
  • No heat in freezing weather, or no cooling in dangerous heat, especially with infants, older adults or anyone with medical needs at home
  • Active water leaks from the unit causing property damage, such as through a ceiling or into a basement

Within a day or two

  • A system that runs but is weak or on-and-off: warm air from the AC, weak heat, short cycling
  • A slow drip of water, or unusual noises while the system still works

Can wait: schedule it

  • Maintenance tune-ups, filter changes and thermostat upgrades
  • Quotes for a new system or a replacement, duct cleaning and air-quality add-ons

This is general guidance, not a diagnosis. If anyone is in danger, call 911 first.

What's on an HVAC quote

  • EquipmentAsk: brand, model, size, efficiency

    The furnace, air conditioner, heat pump or air handler, listed by brand, model and size. Two quotes are only comparable when they name the same type, efficiency and size.

  • Labor & installationAsk: which connections are included?

    The crew's time to remove the old system and install the new one, including the connections to ductwork, gas, electrical and drains.

  • Ducts & line changesAsk: which ducts or lines change?

    Repairs to ducts or the refrigerant lines between the indoor and outdoor units, plus pads, supports and thermostat wiring if needed.

  • ControlsAsk: thermostat included or optional?

    The thermostat and any smart controls, and whether they are included or optional.

  • Permit & inspectionAsk: who pulls the permit?

    Often its own line. The contractor normally pulls the permit.

  • Removal & refrigerantAsk: who recovers the old refrigerant?

    Hauling away the old equipment. Old refrigerant must be recovered, not released, so ask who handles it.

  • WarrantyAsk: parts vs labor, registration?

    The manufacturer's parts warranty and any labor warranty from the contractor. Ask which is which and what registration the manufacturer requires.

  • What a good estimate spells out9 things to look for
    • The contractor's legal name, license number if one applies, and contact details, plus your name and address.
    • What work is included, and what is not.
    • The brand, model and size of major equipment and materials, not just standard or builder grade.
    • Who pulls the permit and who pays for it and for inspections.
    • Cleanup, and what happens to the old materials.
    • A start date and a realistic finish date, and what happens if the schedule slips.
    • Warranty terms: what is covered, for how long and who honors it.
    • When and how you pay, tied to finished stages of work rather than just dates.
    • How changes are handled: a written price for any change before the work happens.

Red flags

4 of 11

  • Size not explained

    Ask for a room-by-room load calculation.

  • Told it's cracked, not shown

    Get a written diagnosis you can take elsewhere.

  • Pressure to sign today

    A fair quote is still fair tomorrow.

  • Refrigerant added again and again

    Ask them to find the leak.

7 more red flags

  • Pushing a full replacement only because your system uses the older refrigerant.

    Existing systems that use it can generally still be serviced.

  • No written quote, or a quote that is a single total with no detail about what is included.

  • A large payment up front, or a request for cash only.

    Some states limit how much a contractor can ask for before work starts.

  • A license number that does not check out.

    Where your state licenses this trade, look the number up yourself on the state licensing board's site.

  • No proof of insurance.

    Ask for a certificate sent to you directly by the insurer or the agent.

  • A price far below every other quote, followed by extras once the work has started.

  • Someone who knocks on your door uninvited, or who will not give recent local references.

Where homeowners say it goes wrong

  • The house is uncomfortable now and they want someone today, not next week
  • They got a surprise huge repair quote and don't trust whether they're being upsold
  • Their unit died in extreme weather and they fear an expensive full replacement
  • They're confused by the 2026 refrigerant changes and worried their old system is obsolete
  • Past contractors no-showed or gave vague arrival windows

Questions to ask

  1. How did you size this system (a load calculation, or just matching the old one), and will you check the ductwork?

  2. What are the exact make, model, efficiency rating and refrigerant of what you are quoting?

  3. Is the permit and inspection included, and can I see a written price for the repair option as well as the replacement?

2 more questions

  1. Are you licensed where this work requires it, and insured? Can I see the license number and a certificate of insurance sent to me by your insurer?

  2. What exactly does the warranty cover, for how long, and who honors it (you, the manufacturer, or both)? Will you put it in writing?

More about heating & cooling

Furnace, boiler or heat pump?A drawing, one part at a time

Heats air; a blower pushes it through ducts to the vents. Cooling needs a separate AC coil on the same ducts.

  • Fuel: gas, oil, propane or electric.
  • Ducts must be sealed and the right size.

Drawing made for this site · simplified, not to scale

Know what you're looking at2 photos
Permit or not?Who pulls it, and what to check first

Commonly permitted

  • Furnace or AC swap
  • Heat pump
  • Gas or electrical work
  • Refrigerant lines

Usually not

  • Thermostat swap
  • Filter change

Your building department decides. If a contractor asks you to pull the permit in your own name, ask why.

Work like this usually needs a permit.

Replacing a furnace, air conditioner or heat pump, or changing gas, electrical or refrigerant connections, is the kind of work building departments commonly permit and inspect. Swapping a thermostat or a filter usually is not.

  • Your building department decides what applies at your address. Rules differ by city and county, and HOA, condo or historic-district rules can add more.
  • Ask who pulls the permit. Normally the licensed contractor does and the price includes it. If a contractor asks you to pull it in your own name, ask why: it can shift responsibility for the work to you.
  • If you are unsure, call your local building department before you sign. Unpermitted work can cause problems with insurance and when you sell.
Words you'll seeSEER2 · HSPF2 · AFUE

SEER2

A cooling-efficiency score for central air conditioners and heat pumps. A higher number means less electricity for the same cooling. Ask for the score of the exact model quoted, not just the brand.

What this trade covers15 kinds of jobs
  • Central AC repair and recharge
  • Furnace repair and ignition/heat-exchanger service
  • Heat pump installation and replacement
  • AC condenser/compressor replacement
  • Annual maintenance tune-ups (cooling and heating)
  • Ductwork inspection, sealing, and replacement
  • Thermostat installation (smart/programmable)
  • Indoor air quality: filters, UV lights, air purifiers, humidifiers
  • Mini-split / ductless system install and service
  • Refrigerant leak detection and repair (R-454B/R-32 conversions)
  • Emergency no-heat / no-cool service calls
  • Boiler and hydronic heating service
  • Blower motor and capacitor replacement
  • Duct cleaning and airflow balancing
  • System efficiency audits and load calculations

How people describe it when it can't wait

  • “My carbon monoxide detector is going off and the furnace just kicked on”
  • “I smell gas / rotten eggs near the furnace”
  • “It's 95 out and my AC is completely dead, my elderly mother is here”
  • “No heat at all and it's below freezing tonight, I have a newborn”
  • “There's water pouring out of the unit into my ceiling/basement”
  • “I see sparks coming from the outside unit”
  • “There's a burning smell coming from the vents when the heat runs”
  • “The furnace is making a loud banging/booming sound when it lights”
  • “The AC outdoor unit is buzzing loudly and won't shut off”
  • “My pipes are going to freeze, the heat has been out for hours”

When it can be planned

  • “I'd like a quote on replacing my old AC unit”
  • “Can I schedule my annual furnace tune-up before winter?”
  • “My energy bills are high, can someone look at my system?”
  • “I want to switch to a heat pump and ask about the tax credit”
  • “Can you install a smart thermostat for me?”
  • “One room is always hotter than the rest of the house”
  • “My filter needs changing and I want a maintenance plan”
  • “Interested in a ductless mini-split for my finished garage”
Rebates and creditsPrograms for your ZIP, and where to look
Find rebates for your ZIP

Rebates and credits change often and differ by state, utility and sometimes county.

  • Start with your state energy office and the ENERGY STAR rebate finder.ENERGY STAR rebate finder (opens in a new tab)
  • The federal 25C and 25D credits ended for property placed in service after 2025-12-31 (IRS: 25C, 25D). Do not count on them for new work, and ask a tax professional about your situation.25C (opens in a new tab)25D (opens in a new tab)
  • Heat pumps, heat pump water heaters and high-efficiency equipment are the items that most often have state or utility rebates.
  • Programs often have conditions: a specific equipment rating, an approved installer, or approval before you buy. Confirm the rules before you sign, not after.
Paying for itBefore you finance anything

Most home projects can be paid in cash or financed. A few basics before you sign anything:

  • Ask for the cash price and the financed price in writing, for the same scope of work. They can differ, because a financing fee (sometimes called a dealer fee) may be built into the financed price.
  • Compare the total you will pay over the whole loan, not just the monthly payment.
  • Read the fine print on same-as-cash and zero-interest offers, especially what happens if the balance is not paid in full by the end of the promotional period.
  • PACE financing is repaid through your property tax bill and can place a lien on your home. Read the terms closely, and consider asking your mortgage servicer how it is treated, before you agree.
  • Utility and state programs sometimes offer low-rate loans for efficiency work. Check yours before accepting the contractor's offer.
  • Take loan paperwork home and read it. A sign-it-today loan is a reason to slow down.

There is more in the financing guide.financing guide

We are not a lender and do not arrange loans. Financing information here is general education; lenders decide terms.

What an expert knows9 topics, each note linked

Notes from public sources, each linked.

Types, pros, cons and lifespanGas or oil furnace · Furnace efficiency labels
Sizing and choosingRight-size, not rule of thumb · Bigger is not better
Maintenance by seasonMonthly in winter and summer · Spring (cooling tune-up)
Code and permit basicsPermits and inspections · Who may handle refrigerant
What moves the priceEfficiency level · Ductwork condition
Common scamsSign today or lose the price · Door-knockers and leftover materials
Ask for this in writingA written proposal · Itemized estimates
Repair or replaceAge is a prompt, not a verdict · Furnace yardstick
Questions to ask an expertHow did you size this? · How will you prove it was installed right?

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General information, not legal, tax, engineering or insurance advice. Updated October 3, 2026. Photo credits

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