Every October we get handed a lot of other companies’ furnace quotes. Some are excellent. Some are a single line with a big number and a signature block. The homeowner holding them usually asks the same question: is this a fair quote? We cannot answer that from the number alone, and neither can you. What you can do is check whether the estimate contains the things that make a number mean something. This is that list, plus the seven signs a quote deserves another set of eyes before you sign.
1. Somebody came to the house
A furnace replacement cannot be quoted from a phone call or a photo of the data plate. Whoever prices the job needs to see the furnace, the space around it, the duct connections, the flue, the gas line, the electrical, and where the condensate would drain if you go high-efficiency. A quote that arrived without a visit is a quote for an average house, and the average house does not exist.
2. A load calculation, not “same size as the old one”
The most common sizing method in the valley is reading the old furnace’s BTU rating and ordering the same thing. The old furnace was often oversized by the builder, and even when it was right, the house has had new windows, insulation, or a finished basement since. A real estimate includes a heat-loss calculation for your square footage, glass, insulation, and orientation, corrected for elevation. Elevation matters more here than most quotes admit: a gas furnace loses capacity as the air thins, and the difference between a Rose Park bungalow and a bench home in Draper or Bountiful is real. We wrote about why the bench changes the math.
3. The exact equipment, with model numbers
“High-efficiency Trane furnace” is a description, not a quote. The estimate should name the manufacturer, the model number, the BTU input, the AFUE rating, the number of stages, and the blower type. Those five facts tell you whether you are being quoted an 80% single-stage furnace with a fixed-speed blower or a 96% two-stage with a variable-speed motor, and those are very different products at very different prices. The 80% versus 96% question has a real answer for your house, and the estimate should show you which one it is quoting.
4. A venting plan
This is the line that separates estimates written at the furnace from estimates written in the truck. An 80% furnace vents through the existing metal flue, and if a water heater shares that flue, the estimate should say what happens to it. A 96% furnace vents through new PVC to an exterior wall and needs a condensate drain, and the estimate should say where both are going. If the venting path is hard on your house, that changes which furnace is the smarter buy, and a good estimate tells you that instead of hiding it in a change order later.
5. What is included, item by item
Read for these, and ask about any that are missing:
- The permit and the inspection that comes with it.
- Gas line connection, drip leg, and shutoff brought to current code.
- Electrical disconnect and any circuit work.
- Venting and combustion air, including changes to the water-heater flue if the furnace leaves it.
- Condensate drain, trap, and pump if needed.
- Duct transitions to connect the new cabinet to the old plenum.
- A new filter rack if the old one does not fit.
- Thermostat, if the new furnace needs a different one to run its stages.
- Haul-away of the old furnace.
- Start-up and commissioning: gas pressure set, temperature rise measured, combustion tested, safeties checked.
If the quote says “installed” and nothing else, the items above are where the surprises live.
6. The warranty, split in two
Every furnace has two warranties, and the estimate should name both. The parts warranty comes from the manufacturer, usually ten years on parts and twenty years to lifetime on the heat exchanger, and usually only if the unit is registered within a set window. The labor warranty comes from the installer and covers the work if something fails. Most installers give one or two years of labor. Ours is five years, free, on every install, and the terms are on the website for anyone to read. An estimate that says “10-year warranty” without saying which one is quoting the manufacturer’s paperwork as if it were the installer’s promise.
7. Rebates, named honestly
There are real rebates, and there are rebates that do not apply to you. The gas-side ThermWise rebate from Enbridge Gas applies to qualifying high-efficiency furnaces anywhere in its service territory. Rocky Mountain Power’s Wattsmart rebates apply to heat pumps, not to gas furnaces, and they do not apply at all if your city runs its own power, which Murray, Bountiful, and most of Lehi do. The federal 25C tax credit for furnaces has expired. A quote that subtracts a rebate you cannot get is a quote with the wrong bottom line. The current verified amounts are on our rebates page, and we only list what we have checked that month.
8. A total, in writing, that does not change today
The price should be one number for the whole job, on paper, with the payment terms next to it. If financing is part of the conversation, the estimate should say what kind. A soft-pull prequalification does not touch your credit score. A lease-to-own payment plan, like the Snap Finance option for customers with an ITIN, is not a loan and has different terms. We explain the differences on the financing page and in how to finance HVAC in Utah.
The seven red flags
- The price was quoted from the driveway or over the phone. See number one.
- The furnace was sized by the old one’s label. Ask what load calculation was done. “We’ve done a thousand of these” is not a calculation.
- No model numbers. You cannot compare “a Goodman” to “a Trane.”
- Today-only pricing. A price that expires when the salesperson leaves is a pressure tactic, not a price. Real prices survive a night of sleep.
- No permit, or a discount for skipping it. The permit is the only inspection of the gas and venting work by someone who does not work for the contractor.
- “Lifetime warranty” with no terms. Lifetime of what, from whom, and what does it cost to keep it in force? If nobody can show you the document, it is a sentence.
- The quote arrived with a diagnosis of “cracked heat exchanger” and no photo. Cracked heat exchangers are real and they are dangerous. They are also the most common reason a repairable furnace gets condemned on the spot. Ask to see the crack. A technician who found one can show it to you.
What we do with the quote you already have
If you have an estimate from someone else and any of the seven flags sound familiar, send it to us. The second opinion is free, it is in writing, and it goes one of three ways: the quote is fair and we say so; the furnace can be repaired and we quote the repair; or the furnace really is done and we quote the replacement properly, with every item on this list, for you to compare. No pressure in any of the three. It is your house and your money.
Ready for an estimate that includes all of it? Call or text (801) 678-5748, Monday through Friday, 8 AM to 8 PM, in English or Spanish. Estimates are free, every install finishes in one day, and the 5-year labor warranty comes with it.