The machine matters less than the hands that size and set it, and a Michigan winter grades the difference every January. A well-installed mid-tier heat pump outperforms a badly installed flagship in any climate; in one with single-digit design nights and live rebate programs whose terms a bidder can either know or fake, the buyer gets unusually sharp tools for telling installers apart before signing. This guide is eight tests, each answerable in a first conversation or a first document, each designed so that a contractor who fails it has told you something you needed to know at the cheapest possible moment.
Test One: The Load Calculation, Performed, Not Estimated
The foundation of every defensible bid is a room-by-room heating and cooling load calculation performed on your actual house: measurements, insulation levels, window areas, orientation, infiltration. The failing answers are familiar and fatal: sizing by square footage, sizing by the old unit's nameplate, sizing by a walk-through glance. The metro's stock punishes all three, because a tightened-up brick bungalow in Dearborn and a drafty two-flat off Woodward can share square footage and sit a ton of capacity apart. Ask one question: will you perform a room-by-room load calculation and give me the report? Anything but yes ends the interview.
Test Two: Capacity at Design Temperature, in Writing
Southeast Michigan's design nights sit in the single digits, and the bid must show the proposed machine's published heating output at that condition, printed beside your calculated load, per the discipline in our cold-weather guide. A contractor fluent in this climate produces the capacity table without being asked. One who offers nameplate tonnage and reassurance is selling in a warm-market accent, and the house will translate the difference into strip-heat bills every snap.
Test Three: Rebate Fluency, the Live-Money Tell
This market has real program money, which makes program fluency a checkable credential. DTE pays up to $1,200 for resistance-to-heat-pump conversions; Consumers Energy pays $300 to $350 by tier and requires a participating contractor; Great Lakes Energy's co-op checks carry a 60-day filing clock; the federal 25C and 25D credits ended December 31, 2025. The full map is in our rebates guide. Test the bidder against it. One who cites the expired federal credits as live money has failed on page one. One who promises the DTE headline to a gas-heated house has failed the same way. And one who names the right program for your meter, states its current terms, and notes their participating status where it matters has passed a test that is nearly impossible to fake. Staleness about money travels with staleness about refrigerants, code, and commissioning.
Test Four: The Panel Question
Much of the metro's older stock runs 100 amp service, and a whole-home conversion can force new circuits or a service upgrade with utility coordination and lead time attached. The honest bidder opens the panel at the site visit and prices what they find; the evasive one discovers it after signing, as a change order. Put the question in the first phone call: what will you check on my electrical panel, and will panel work be itemized in the quote? Full cost context sits in our installation cost guide.
Test Five: Ducts Measured, Never Assumed
Postwar Warren, Livonia, and the downriver suburbs mostly carry reusable trunks, but ducts sized for a furnace's hot, fast air can choke a heat pump's steadier flow. The credible contractor measures static pressure and inspects for leakage before sizing anything; corrections priced upfront cost less than comfort complaints diagnosed later. In the prewar stock, where usable ducts often do not exist, the same test changes shape: head placement and line-set routing through plaster and brick, decided by someone who can point to prewar work they have done, not work they believe they could do.
Test Six: Licensing, Permits, and the Refrigerant Line
The baseline is unglamorous and non-negotiable: a licensed Michigan mechanical contractor, insurance certificates on request, permits pulled for the electrical and mechanical work rather than skipped to save a week. The licensing line is also a program line: co-op rebates require a licensed Michigan mechanical contractor by rule, and Consumers Energy requires participating status, so cutting the corner can cost the check as well as the protection. Add one 2026-specific test: current quotes should specify R-454B equipment, and a bid built on outgoing refrigerant platforms is a bid built on someone's warehouse problem.
Test Seven: References That Match Your House
Ask for references from projects like yours, and be literal about it. A ducted changeout in a Livonia ranch says little about a multi-head conversion in a Ferndale prewar, and neither says much about a wind-exposed Grosse Pointe colonial on Lake St. Clair. Then ask each reference two winters' worth of questions: did the sizing hold through the cold snaps, and did the bills match what the contractor projected? The fuel arithmetic they should have projected honestly, including the close gas race, lives in our fuel comparison.
Test Eight: Commissioning, the Quiet Divider
The gap between an installed heat pump and a performing one closes at commissioning: refrigerant charge verified by measurement, airflow set to specification, controls and backup staging configured so the strips wait for the nights they were sized for, defrost behavior explained before the first steamy cycle alarms the household. Ask what the commissioning process includes and what documentation you receive; on rebate projects, that documentation is also the filing packet. Contractors who treat startup as flipping a breaker leave capacity and efficiency you paid for sitting in the equipment, and the strips will quietly bill you for the difference.
How the Eight Tests Behave in a Real Search
Run three bidders through the same document set and the market sorts itself quickly. Expect one bid to arrive fast, low, and paperless, with "rebates available" doing the work a load calculation should; it fails tests one, two, and three at once. Expect one bid to arrive high and thorough; make it justify its scope line by line, which a good contractor does without flinching. The bid worth signing is usually the one that produced documents before being asked, named the right program for your meter with current terms, and answered the panel and duct questions from measurements. Price still matters, but only between bids that passed; a failing bid at any price is the most expensive object in the stack.
The Short Version
Eight tests: a performed load calculation, published capacity at the design night, rebate fluency checked against the real programs, the panel opened and priced, ducts measured or prewar routing proven, Michigan licensing with permits and R-454B, references that match your housing stock, and real commissioning. No single test requires expertise to administer; every one requires the contractor to demonstrate theirs. A Michigan January grades the winner.
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