HVAC acquisitions close when buyers are confident in what they're buying. That confidence comes from a structured diligence process that examines financial quality, operational health, legal exposure, and integration readiness. This checklist reflects what experienced buyers actually check — not a generic M&A framework, but HVAC-specific diligence items that have surfaced real surprises in real deals.
For sellers: Every item on this list is something you'll be asked about. Preparing your answers — and the supporting documentation — before diligence begins is what separates deals that close on time from deals that grind through re-trades.
Financial Due Diligence
Financial Quality
3 years of P&L statements — accrual basis, signed by CPA. Cash basis requires restatement before QoE begins.
3 years of tax returns — Federal and state. Verify that P&L and tax return revenue reconcile (unexplained gaps are a red flag).
3 years of balance sheets — Focus on accounts receivable aging, deferred revenue, and owner distributions vs. retained earnings.
TTM (trailing 12 months) financials — Current period performance; verify consistency with prior year run rate.
EBITDA bridge from reported to adjusted — Full add-back schedule with documentation for each item. Owner's comp, personal vehicles, one-time items.
Revenue breakdown by type — Service/repair vs. replacement vs. new construction vs. maintenance agreements. Monthly detail for 3 years.
Gross margin by revenue category — Blended gross margin and breakout by segment. Flag any category below 40%.
Monthly revenue trend — Seasonality analysis. Verify no unusual spikes that inflate EBITDA in the acquisition period.
Recurring Revenue Analysis
Service agreement count and annual value — Total active agreements, average annual value, renewal rate. Declining renewal rate is a serious flag.
Service agreement cohort retention — What % of Year 1 agreements renew in Year 2? Year 3? Declining cohort retention undermines the recurring revenue story.
Commercial contract list — Every commercial maintenance contract with term, expiration, and annual value. Change-of-control clauses in commercial contracts.
Customer concentration analysis — Top 10 customers by revenue. Flag any customer above 10% of total.
Working Capital and Cash Flow
Accounts receivable aging — Any balance 60+ days past due is a risk item. High DSO relative to peers suggests collection problems.
Deferred revenue — Service agreements collected in advance create deferred revenue liability. Verify proper accounting treatment.
Normalized capex — 3-year capex history by category (fleet, equipment, facilities). Identify deferred capex that will hit post-close.
Working capital peg — Define "normal" working capital for the deal so neither party gets surprised at close by seasonal cash timing.
Operational Due Diligence
People and Workforce
Full employee roster with tenure, title, and compensation — Include all W-2 employees and 1099 contractors. Identify any workers who should be employees.
Technician certification list — EPA 608, NATE certifications, state contractor licenses. Verify current status and expiration dates.
Technician turnover rate (3 years) — Above 30% annual tech turnover is a red flag. Understand root causes before attributing to market conditions.
Key person dependencies — Who else besides the owner knows the customer relationships, commercial accounts, and operational knowledge?
Non-compete and retention plan for key employees — Especially for service managers and master technicians.
Benefits and compensation benchmarking — Are technicians paid at, above, or below market? Below-market comp is a post-close attrition risk.
Fleet and Equipment
Complete fleet inventory — Year, make, model, mileage, owned vs. leased, condition. Identify vehicles needing near-term replacement.
Fleet maintenance records — Systematic maintenance (oil changes, tires, DOT compliance) or reactive? Deferred maintenance is a direct purchase price adjustment.
Equipment inventory and condition — Specialty HVAC tools, manifold gauges, recovery equipment, leak detectors. Replacement cost and timeline.
Parts and inventory valuation — Current parts inventory count and value. Obsolete or slow-moving inventory should be excluded from working capital.
Operations and Technology
Field service management (FSM) system — Platform, version, data quality. Is job history, customer data, and equipment data in the system or in technicians' heads?
Dispatch and scheduling processes — Documented? Average response time. How is emergency dispatch handled after hours?
Customer data quality — Full name, address, phone, email, equipment model/serial, service history. Clean data has direct value; degraded data requires post-close remediation.
Online reputation audit — Google, Yelp, BBB. Star rating, review count, response rate, pattern of complaints. Look for a cluster of negative reviews in any 3-month window.
Marketing spend and ROI — Digital marketing budget by channel. Cost per lead, close rate, customer acquisition cost. Is growth organic or paid?
Legal and Compliance
Licensing and Regulatory
State contractor licenses — All active licenses, holder names, expiration dates. Verify transferability upon ownership change in each state of operation.
EPA 608 compliance — Refrigerant handling certifications for all technicians handling refrigerants. Documentation of refrigerant purchases and disposal.
OSHA compliance history — Any OSHA violations, citations, or active investigations. Workers' comp claim history by year.
Permit pull history — Active permits, permit failure rate, any open violations with local building departments.
Contracts and Agreements
Facility leases — Terms, expiration, renewal options, change-of-control provisions. Is the facility adequate for current headcount and fleet?
Equipment and vehicle leases — Terms, buyout options, transfer mechanics.
Vendor agreements — Equipment supplier pricing arrangements, manufacturer dealer agreements, distributor relationships. Some arrangements have change-of-control clauses.
Insurance policies — GL, workers' comp, auto, E&O. Coverage limits, claims history (3 years), premium trends.
Pending litigation and disputes — Any active or threatened legal claims, warranty disputes, or customer complaints in legal channels.
Tax and Financial Compliance
Tax compliance status — Federal, state, and local taxes current. Any open audits, assessments, or payment plans.
Payroll tax compliance — Quarterly 941s filed and paid. Any payroll tax liens or payment arrangements.
State sales tax compliance — Service agreement revenue tax treatment varies by state. Verify proper collection and remittance.
Integration Planning
Day-One Readiness
Employee communication plan — What will technicians and staff be told on Day 1? Who tells them? What changes? What stays the same?
Customer communication plan — Service agreement customers notified of ownership change? Any commercial accounts that need personal outreach before close?
Founder transition agreement — Scope of role, reporting structure, decision-making authority, and compensation for the 12–24 months post-close.
Bank and vendor account transitions — Identify all accounts, credit cards, and payment arrangements that require ownership transfer notifications.
Software and systems access — Admin access to FSM, email, accounting, marketing platforms transferred to buyer at close.
For operators preparing for sale: Work through this checklist as a seller before you engage buyers. Every item you can answer confidently — with documentation — reduces diligence friction, shortens the timeline, and gives buyers fewer reasons to re-trade the price.
Benchmark Before You Go to Market
Know where your HVAC metrics stand relative to comparable operators before any buyer does. Gross margin, recurring revenue %, EBITDA — graded A–F in 4 minutes.
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