Sizing method
A calculation takes hours. Matching the old nameplate takes seconds and frequently carries a decades old error forward.
What the contractor owes you
The responsibilities, and the questions that test whether they were met
A mechanical contractor is responsible for considerably more than supplying and fitting equipment. The obligations include sizing the system against the building rather than against what was there before, ensuring the distribution can carry what the equipment produces, complying with the code requirements that apply to venting, gas piping, electrical work and combustion air, obtaining permits where the work requires them, and demonstrating at handover that the finished installation performs as designed. Very little of that is visible in a price.
Start with the verifiable facts. Licensing requirements vary by jurisdiction and usually by trade, and a contractor should be able to state theirs without hesitation. Insurance protects you against property damage caused during the work. Bonding protects you if the work is abandoned incomplete. All three are reasonable to ask about and a reluctance to discuss any of them is itself informative.
Then ask the five questions that reveal whether design work actually happened. Was a room by room load calculation performed, and can you see it. What airflow is each room supposed to receive and how will that be verified. What is the current static pressure and what will it be afterwards. For a heat pump, what is the balance point and what carries the load below it. For a gas appliance, what combustion readings will be recorded at handover. A contractor who has designed the installation answers these directly. One who has not will move the conversation toward brands, efficiency ratings and financing.
The written scope is where those answers become commitments. It should name model numbers for every component including the indoor coil, describe any ductwork or electrical work as separate itemised elements rather than folding them into a single figure, state who pulls the permit, set out the labour warranty term and the equipment warranty term separately, and say who submits the manufacturer registration. A one line quote naming a brand and a price is not a scope of work, and the disputes that follow such quotes are almost always about something that was never written down.
| What to ask | A designed answer sounds like | A warning sign sounds like |
|---|---|---|
| Was a load calculation done? | Yes, here is the summary by room | We matched what you had, it has always worked |
| What airflow should each room get? | A figure per room, verified at handover | The equipment is rated for the square footage |
| What is the static pressure now? | A measured number, and the target afterwards | The ducts look fine |
| Is the indoor coil a tested match? | Yes, here is the pairing | Any coil works with any outdoor unit |
| Who pulls the permit? | We do, and we attend the inspection | A permit is not really needed for this |
| What readings do I get at handover? | Charge, airflow, electrical, combustion | It will be running when we leave |
| Who registers the warranty? | We submit it and send you confirmation | You can do that online |
One more thing worth knowing is how to read a bid that is genuinely hard to fault but still wrong for you. A contractor can do everything correctly and still specify a larger project than you need, because the calculation supports it and nobody asked about your priorities. If your actual complaint is one uncomfortable room, say so plainly and ask whether anything smaller would address it. A good contractor will tell you when a duct correction solves the problem that a full replacement was quoted for, and that conversation only happens if you start it.
At handover you should receive the load calculation summary, the commissioning readings, the permit and inspection record where applicable, the manufacturer registration confirmation, and the warranty terms in writing. Those documents are what let any future technician work on the system with data rather than guesswork, and they are what let you hold anyone to what was promised.
Comparing bids
Six ways two similar prices can hide very different work
Each of these is a legitimate place to save money, and each changes what you are buying.
Coil pairing
A tested indoor and outdoor combination has published performance. A mismatched pair has none, and no technician can later diagnose it.
Ductwork treatment
Quoted as an itemised element, folded invisibly into the equipment price, or simply ignored and blamed afterwards.
Evacuation standard
Measured on a micron gauge, or timed with a stopwatch. The difference surfaces as a compressor failure years later.
Commissioning
Two hours of measurement and documentation, or a thumbs up and a van door closing.
Permit and registration
Handled by the contractor, or quietly left with you to discover when you sell the property or make a claim.
Our commitments
What we hold ourselves to on every job
Stated plainly so you can hold us to them, and compare them against anyone else.
NATE certified techniciansCertification earned by examination and renewed on a cycle, covering service and installation.
Licensed, bonded and insuredAll three, and we expect to be asked about them rather than taken on trust.
EPA Section 608 complianceRefrigerant recovered and documented rather than vented, as federal rules require.
Flat rate pricingFrom a published schedule, approved by you before work begins, so careful work costs no more.
Documentation at handoverReadings, registration, permit record and warranty terms, in writing.
Written workmanship warrantyLabour warranted in writing, with parts covered by the manufacturer.
Customer testimonies
Feedback on how the work is scoped
I asked all seven questions of three contractors. Only one had answers, and the difference in the written scope was obvious once I knew what to look for.
The scope named the indoor coil model as well as the outdoor unit. The other two quotes only named a brand.
They talked me out of the larger job and explained exactly why the smaller one would solve the problem.
Contractor questions
Licensing, bids, permits and what to expect at handover
How many quotes should I get?
Three is the usual advice and it is reasonable, provided you ask all three the same questions. Three prices for work that has not been defined tells you very little, because the cheapest may simply have excluded the ductwork and the commissioning.
What makes comparison possible is a consistent set of questions and a written scope from each. Once you have those, the differences become legible: one has calculated the load and priced a duct correction, another has matched the old size and said nothing about distribution. At that point the price difference usually explains itself.
Is the cheapest bid ever the right choice?
Frequently, when the scopes genuinely match and one contractor simply has lower overheads or wants the work. There is nothing inherently suspicious about being competitive.
It is the wrong choice when the price is lower because something was left out. The usual omissions are the load calculation, any ductwork correction, the permit, the commissioning, and occasionally the indoor coil. None of those absences are visible in a headline figure, which is why the written scope matters more than the number at the bottom of it.
Do I really need a permit for a replacement?
Requirements vary by jurisdiction, but work involving gas piping, venting or electrical modification is commonly permitted and inspected. The contractor should know what applies locally and should be pulling it as part of the job.
The argument for not skipping it is practical rather than moral. An unpermitted installation can complicate a property sale, can give an insurer grounds to question a claim, and removes an independent check on work you cannot see. A contractor who suggests skipping the permit is telling you something about how they work.
How do I check licensing and insurance?
Ask for the license number and the name it is held under, then verify it with the issuing authority rather than accepting a document. Most jurisdictions publish a searchable register, and it takes a couple of minutes. Check that the name on the license matches the business you are contracting with, since those occasionally differ.
For insurance, ask for a certificate issued directly by the insurer rather than a copy supplied by the contractor, and check the policy is current on the dates your work is scheduled. None of this implies suspicion of anyone in particular. It is ordinary diligence on a significant purchase, and a contractor who works properly will be used to being asked.
What if something goes wrong after the work?
Labour should carry a written workmanship warranty and equipment carries the manufacturer warranty, and those two terms should be stated separately in the scope because they usually differ in length. Where a repair falls under either, the return visit should not be a negotiation.
The documentation is what makes that straightforward. Commissioning readings establish how the system performed when it was handed over, so a later dispute about whether something was ever right has evidence behind it rather than two recollections. That is the underrated reason for insisting on the paperwork.
Related services
Where the detail lives
The pages below set out in detail what each type of project should involve.
Thermostat Repair & Replacement
Bathroom Plumbing Repair
#link-bathroom-plumbing-repair#
Drain Cleaning
#link-drain-cleaning#
Frozen Pipe Repair
#link-frozen-pipe-repair#
Backflow Testing
#link-backflow-testing#
Ask us the seven questions
We would rather be measured against them than against a price alone, and across Zeeland, MI they are the fastest way to tell designed work from assembled work.
Annual testing is quoted per assembly, with repair or replacement priced separately.