What to ask before you sign
Most of what separates a cheap bid from an expensive one is scope, not price. Ask these up front and the quotes you get back are comparable — which is most of the work.
8 questions, in the order they cost you money
This is the exact list our checker produces for a quote that has told you nothing yet. It is generated from the ruleset, not written separately, so it cannot drift from what the tool does.
The refrigerant is not named.
R-410A, R-454B and R-32 are not interchangeable, carry different service costs, and R-454B/R-32 are A2L which changes installation requirements.
Ask them“Which refrigerant does this system use — R-454B, R-32, or R-410A?”
No AHRI reference number for the outdoor + indoor combination.
Efficiency ratings are a property of the MATCHED pair, not of the outdoor unit. Manufacturer warranties also condition eligibility on an AHRI-rated matched system — Trane's base limited warranty states the equipment "must be part of an AHRI rated and matched system". Without the reference number you cannot confirm either the rating or your warranty eligibility.
Ask them“What is the AHRI reference number for this exact outdoor/indoor combination? I want to look it up at ahridirectory.org.”
No permit line.
The model code (IRC R105.2) exempts only minor parts and self-contained appliances — a full equipment replacement is not exempt. Local adoption and enforcement vary, but an unpermitted install can mean retroactive permitting and re-inspection cost, and disclosure obligations at resale in some states.
Ask them“Is the permit included in this price, and who pulls it?”
No removal or disposal of the old equipment.
Refrigerant must be recovered by an EPA-certified technician. If this is not in the quote it is either assumed or it becomes a change order.
Ask them“Does the price include removing and disposing of the old system, including refrigerant recovery?”
No Manual J load calculation.
IRC M1401.3 requires sizing based on a calculated load, though it permits "other approved methodologies" and enforcement varies. Rule-of-thumb sizing (tons per square foot) commonly produces oversized systems, which short-cycle, control humidity poorly and wear faster. Do not expect a large annual energy saving from correct sizing — the evidence for that is weaker than the industry suggests.
Ask them“Did you perform a Manual J load calculation, and can I see it?”
No labor or workmanship warranty term.
The manufacturer parts warranty and the contractor labor warranty are separate. Parts coverage does not pay for the labor to install the part.
Ask them“What is your labor warranty, in years, and what does it cover?”
No start-up or commissioning step.
Refrigerant charge verification and static pressure measurement are what determine whether the system actually delivers its rated performance.
Ask them“Does the install include commissioning — verified refrigerant charge and a static pressure reading?”
No payment schedule or deposit terms.
Deposit size and payment timing are negotiable and vary widely between bids for the same job.
Ask them“What is the deposit, and what triggers each subsequent payment?”
Three questions that work on any trade
“What is deliberately not included?” A line reading NOT INCLUDED: permit is not the same as silence. It is a known cost, priced out on purpose, and a bid that includes it is not more expensive — it is more complete.
“What is the deposit, and what triggers each payment after it?” Deposit size is negotiable and varies wildly between bids for identical work. Check what your state allows.
“What is your labor warranty, in years?” The manufacturer’s parts warranty and the contractor’s labor warranty are separate things. Parts coverage does not pay anyone to install the part.
Other trades
We can already price sheet_metal, plumbing, electrical, roofing, windows, carpentry and more. Trade-specific checklists for those need the compliance rules built first, which is slower work — weeks per trade, per jurisdiction — and we would rather ship nothing than a checklist that sounds authoritative and is not.