Due Diligence Checklist · HVAC

HVAC Business Due Diligence Checklist for Buyers

Before you wire a dollar, verify every maintenance contract, technician license, and fleet title. This checklist covers the critical items that separate a great HVAC acquisition from an expensive mistake.

Acquiring an HVAC business in the $1M–$5M revenue range offers genuine upside — recurring maintenance revenue, recession-resistant demand, and strong SBA financing eligibility. But the same features that make HVAC attractive also create specific acquisition risks. Owner-technician dependency, undocumented service agreements, aging fleet liabilities, and licensing transferability issues can quietly destroy deal value after close. This checklist organizes due diligence into seven core categories so buyers — whether ETA searchers, independent owner-operators, or PE-backed roll-up platforms — can systematically verify what they're buying before committing capital. Prioritize the critical items first, and engage an HVAC-specialized M&A advisor or business broker alongside a CPA and attorney experienced in trades business transactions.

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Financial Statements & Revenue Quality

Verify that reported earnings are real, recurring, and transferable — not inflated by one-time events, owner add-backs that don't hold up, or undocumented cash transactions common in owner-operated trades businesses.

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Request 3 years of P&L statements, balance sheets, and tax returns (business and personal if sole proprietor)

Cross-referencing tax returns against internal financials reveals unreported cash revenue, inflated expenses, and discrepancies that affect true SDE or EBITDA calculations.

Red flag: Significant variance between tax returns and internal P&L — particularly if the seller claims large add-backs not visible on the tax filing.

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Reconstruct Seller's Discretionary Earnings (SDE) with itemized owner add-backs supported by documentation

HVAC owner-operators routinely run personal vehicles, cell phones, insurance, and family payroll through the business. Each add-back must be verifiable and non-recurring to be credible to lenders.

Red flag: Add-backs exceeding 20–25% of reported net income without supporting documentation, or add-backs for expenses that will continue post-transition.

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Segment revenue by type: maintenance contracts, installation/replacement, repair/break-fix, and new construction

Maintenance contract revenue is worth more at a higher multiple than break-fix revenue. Understanding the mix determines whether the stated multiple is justified.

Red flag: More than 60–70% of revenue is break-fix with no documented maintenance agreement base — indicating reactive, unpredictable revenue.

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Review monthly revenue by month for the past 3 years to assess seasonality and identify anomalies

HVAC revenue is inherently seasonal (summer cooling, winter heating peaks). Understanding the seasonal curve is essential for working capital planning and SBA lender projections.

Red flag: Revenue spikes in the final 12 months before listing with no clear operational explanation — may indicate pulled-forward demand or unusual pricing.

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Analyze accounts receivable aging report for commercial accounts

Slow-paying commercial customers or uncollected receivables inflating revenue can signal working capital problems that emerge immediately post-close.

Red flag: More than 15% of receivables aged beyond 90 days, or a single commercial customer with a large outstanding balance.

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Confirm whether QuickBooks, ServiceTitan, or other software records reconcile with reported revenue

Field service management software like ServiceTitan or Jobber creates an independent revenue audit trail through job records, invoices, and payment logs.

Red flag: Seller cannot or refuses to provide software export data, or there is material inconsistency between job records and reported invoiced revenue.

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Review any owner loans, related-party transactions, or personal real estate leases tied to the business

Owners sometimes charge above-market rent on company-used real estate they personally own, artificially reducing reported earnings. These must be normalized.

Red flag: Lease payments to owner-related entities at above-market rates, or undisclosed loans from the business to the owner appearing on the balance sheet.

Maintenance Agreements & Recurring Revenue

Maintenance contracts are the crown jewel of an HVAC business acquisition. Verify contract count, renewal rates, monthly recurring revenue, and whether agreements are written, transferable, and enforceable by a new owner.

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Obtain a full roster of active maintenance service agreements with contract start dates, renewal dates, and annual contract value

This is the single most important revenue quality indicator in an HVAC acquisition. A minimum of 50 active contracts is the baseline — serious buyers target 150–300+.

Red flag: Seller cannot produce written contracts and instead references verbal or handshake maintenance arrangements that are not documented.

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Calculate Monthly Recurring Revenue (MRR) from maintenance agreements and verify against bank deposits

MRR from service agreements provides the predictable revenue base that justifies premium multiples. It must be verifiable against actual cash receipts.

Red flag: MRR calculated by seller significantly exceeds amounts visible in bank statement deposits attributed to recurring billing.

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Review contract renewal rates over the past 2–3 years

A renewal rate below 80% signals customer dissatisfaction, owner-dependent relationships, or poor service delivery — all of which increase post-close revenue risk.

Red flag: Renewal rate below 75%, or a large batch of contracts up for renewal within 90 days of close with no retention plan in place.

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Confirm maintenance agreements are assignable to a new owner without customer consent requirements

Contracts that require customer consent to transfer introduce significant revenue risk at close, particularly if the owner's personal relationship drove the agreement.

Red flag: Agreements contain non-assignment clauses, or the seller admits that most customers have informal rather than signed arrangements.

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Request a breakdown of residential vs. commercial maintenance agreements and average annual contract value

Commercial contracts carry higher average contract value but also more concentration risk. Residential contracts are more diversified but lower value individually.

Red flag: One or two commercial maintenance agreements representing more than 25% of total maintenance MRR — loss of a single account would be material.

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Verify payment collection method and frequency — prepaid annual, monthly auto-pay, or invoiced

Prepaid annual contracts collected upfront create favorable working capital dynamics; invoiced contracts create collection risk and AR aging exposure.

Red flag: Majority of maintenance agreements are invoiced with net-30 or net-60 terms and no auto-pay — indicating elevated collection risk and working capital drag.

Technician Workforce & Licensing

In HVAC, your workforce is your product. Verify that licensed, certified technicians are employed independent of the owner, that certifications are current, and that employment agreements reduce departure risk post-close.

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Confirm all field technicians hold valid EPA Section 608 certification for refrigerant handling

EPA 608 certification is a federal legal requirement for handling refrigerants. A technician without it cannot legally perform core HVAC work, creating compliance and liability exposure.

Red flag: Any technician performing refrigerant work who cannot produce a valid EPA 608 certificate — immediate compliance risk.

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Verify state contractor license status and confirm the license is transferable or that a qualifying licensee will remain post-close

Most states require an HVAC contractor license tied to a qualifying individual. If the owner is the qualifier and departs at close, the business cannot legally operate until a new qualifier is established.

Red flag: Owner is the sole qualifying licensee with no licensed technician on staff capable of assuming the qualifier role post-close.

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Review employment status of all technicians — W-2 employees vs. 1099 contractors

Misclassification of technicians as independent contractors exposes the buyer to IRS back-tax liability, state labor board penalties, and workers' compensation gaps.

Red flag: More than one or two technicians classified as 1099 contractors performing regular, recurring work — a significant misclassification risk that survives asset purchase.

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Obtain copies of NATE (North American Technician Excellence) certifications where applicable

NATE certification is the industry's gold standard for technician competency. It signals a professional, trainable workforce and is often required for manufacturer warranty work.

Red flag: No technicians hold NATE certifications in a business that markets itself on premium service quality or performs manufacturer warranty work.

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Review technician tenure, compensation, and any non-compete or employment agreements

Technician turnover post-close is one of the most common sources of deal value destruction. Long-tenured employees with market-rate compensation are less likely to leave after a transition.

Red flag: No written employment agreements, below-market wages, or multiple technicians with less than 12 months tenure — suggesting high turnover culture.

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Assess owner involvement as a field technician — how many billable hours per week does the owner personally generate?

An owner running 20–40 hours per week of billable field work creates a revenue gap at close that must be filled by hiring or redistributing work among existing staff.

Red flag: Owner generates more than 30% of billable field hours with no identified replacement plan — critical key-person dependency.

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Confirm workers' compensation and general liability insurance is current and covers all employees

Lapsed or inadequate insurance coverage is an SBA lender red flag and creates immediate liability exposure for an acquiring buyer at close.

Red flag: Insurance certificates showing lapsed coverage, uninsured subcontractors on active jobs, or claims history with multiple incidents in the past 3 years.

Fleet, Equipment & Capital Expenditures

HVAC businesses are capital-intensive. Verify fleet condition, ownership status, deferred maintenance, and identify any capital expenditure requirements in the 12–24 months post-close before they erode acquisition returns.

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Obtain a complete fleet inventory with year, make, model, mileage, and title status for every vehicle

Service vehicles are the operating backbone of an HVAC business. Older, high-mileage fleets with deferred maintenance can require $30K–$80K per unit to replace, materially impacting post-close returns.

Red flag: Fleet averaging 150,000+ miles with no documented maintenance records, or vehicles not titled in the business name — complicating the asset transfer.

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Review vehicle maintenance records, inspection history, and any outstanding repair needs

Deferred vehicle maintenance is a hidden liability that surfaces within 6–12 months of close. A pre-purchase mechanical inspection on all fleet vehicles is strongly advisable.

Red flag: Maintenance records unavailable or inconsistent, multiple vehicles with deferred repairs, or active check-engine issues disclosed during walkthrough.

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Assess diagnostic equipment, vacuum pumps, refrigerant recovery machines, and specialty tools for condition and value

Quality diagnostic and service equipment supports technician productivity and job quality. Aging or incomplete tool inventory requires immediate capital investment.

Red flag: Critical diagnostic or refrigerant handling equipment that is outdated, non-functional, or not included in the asset sale.

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Verify ownership vs. lease status of all equipment included in the sale

Leased equipment may not transfer automatically in an asset sale, and lease assumptions require lender and lessor approval — complicating SBA financing timelines.

Red flag: Key equipment subject to financing or lease agreements with personal guarantees that cannot be assumed by the buyer entity.

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Identify any company-owned warehouse, shop space, or storage facility and confirm lease terms or ownership

The operating location anchors dispatch, parts inventory, and technician reporting. A short-term lease with no renewal option creates post-close operational instability.

Red flag: Shop lease expiring within 18 months of close with no renewal clause, or landlord relationship tied personally to the owner-seller.

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Estimate capital expenditure requirements for fleet replacement over 24–36 months post-close

Buyers must model post-close capex requirements into return projections. Underfunding fleet replacement is a common first-year mistake in HVAC acquisitions.

Red flag: Seller cannot or will not discuss fleet replacement timeline, or attempts to exclude fleet capex from normalized EBITDA without justification.

Customer Base & Concentration Risk

A strong HVAC business has diversified revenue across many residential and commercial customers. Concentration in one account or segment creates fragility — verify the composition before pricing the deal.

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Request a full customer revenue report by customer for the trailing 12 months and prior 2 years

Identifying which customers drive what percentage of revenue is foundational to understanding deal risk. No single customer should represent more than 15–20% of total revenue.

Red flag: Any single customer — residential property management group, commercial building owner, or general contractor — representing more than 20% of annual revenue.

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Verify whether top commercial customers are on written service agreements or verbal arrangements

Commercial accounts without written contracts can walk at transition. Written agreements with defined terms provide protection and transferability assurance.

Red flag: Top 3–5 commercial accounts operating on verbal or handshake arrangements with no executed service contracts.

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Assess customer relationship ownership — are relationships tied to the owner personally or to the company brand?

When the owner is the primary contact for key accounts, customer retention post-close depends entirely on transition quality and introduction effectiveness.

Red flag: Owner is primary or sole contact for accounts representing more than 30% of revenue with no relationship built between those customers and employed staff.

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Review Google reviews, BBB profile, and any Angi or HomeAdvisor ratings for reputation assessment

Online reputation drives inbound residential leads and customer renewal decisions. A damaged reputation requires significant marketing investment to repair.

Red flag: Average Google rating below 4.0 with recurring complaints about service quality, no-shows, or billing disputes — indicating systemic service delivery issues.

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Confirm customer geographic concentration within the licensed service territory

Revenue concentrated in a small geographic area limits growth and increases vulnerability to local economic disruption or a new competitor entering the territory.

Red flag: Majority of revenue concentrated in a single zip code or subdivision with no demonstrated ability to expand service territory.

Licensing, Compliance & Legal

HVAC is a heavily regulated trade. Licensing lapses, refrigerant compliance violations, contractor board complaints, or unresolved liens can block SBA financing, delay close, and create post-close liability.

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Verify current state HVAC contractor license status and confirm no pending complaints, investigations, or disciplinary actions

An active contractor license in good standing is non-negotiable for business operations. Any disciplinary action or complaint triggers SBA lender scrutiny and may delay or kill financing.

Red flag: Any active complaint with the state contractor licensing board, or a license that has lapsed and been reinstated within the past 24 months.

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Confirm EPA Section 608 compliance — refrigerant purchase logs, recovery equipment calibration records, and disposal documentation

EPA refrigerant regulations carry civil penalties of up to $44,000 per violation per day. Undocumented refrigerant handling creates significant environmental liability for the buyer.

Red flag: No refrigerant purchase or recovery logs maintained, missing disposal documentation, or evidence of venting refrigerant rather than proper recovery.

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Review R-22 phase-out compliance and existing R-410A / A2L refrigerant inventory and handling protocols

R-22 is now fully phased out and its handling is tightly regulated. The transition to lower-GWP refrigerants (A2L class) requires updated equipment, training, and safety protocols.

Red flag: Active inventory of R-22 without proper documentation, or technicians untrained on A2L refrigerant handling requirements for next-generation equipment.

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Search for UCC filings, tax liens, judgment liens, or equipment financing obligations against the business

Undisclosed liens attach to business assets and can follow an asset purchase if not properly cleared at close. UCC searches must be conducted in all states of operation.

Red flag: Outstanding federal or state tax liens, judgment liens from prior customers or subcontractors, or undisclosed equipment financing obligations.

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Review any pending litigation, warranty claims, or customer disputes

Active or threatened litigation creates contingent liabilities that can surface post-close as claims against the acquired business or its principals.

Red flag: Any undisclosed litigation, active insurance claims related to property damage or personal injury on job sites, or pattern of unresolved warranty callbacks.

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Confirm business insurance — general liability, workers' compensation, commercial auto, and umbrella policy — is current and adequate

SBA lenders require proof of adequate insurance at close. Gaps in coverage — particularly workers' comp or commercial auto — create immediate lender and operational risk.

Red flag: Lapses in workers' compensation coverage, vehicles used for business without commercial auto coverage, or general liability limits below $1M per occurrence.

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Verify all subcontractor relationships have current certificates of insurance on file

Subcontractors without their own insurance coverage can create general liability and workers' comp exposure for the primary contractor on jobs where incidents occur.

Red flag: Subcontractors regularly used without current COIs on file, or subcontractor work performed without written agreements defining scope and liability allocation.

Operations, Systems & Transition Planning

Operational infrastructure determines whether the business runs without the owner. Evaluate dispatch systems, software data quality, SOPs, and seller transition commitment before finalizing deal terms.

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Assess field service management software in use — ServiceTitan, Jobber, Housecall Pro — and request 12+ months of data export

Software data is an independent operating record covering job history, customer records, revenue by technician, and maintenance agreement tracking. It validates financial claims and supports post-close continuity.

Red flag: Business operating on paper dispatch or basic spreadsheets with no digital job history — creating a data gap that complicates post-close customer management.

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Review dispatch and scheduling process — is it owner-managed or delegated to a dispatcher or office manager?

Owner-managed dispatch creates a critical operational bottleneck at close. A dedicated dispatcher or office manager who can continue post-close is a significant value driver.

Red flag: Owner personally handles all dispatch, customer callbacks, and scheduling with no trained backup — a key-person dependency extending beyond field work.

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Confirm seller availability for a transition period of 60–180 days post-close and negotiate terms in the purchase agreement

A defined transition period with the seller available for technician introductions, customer relationship handoffs, and operational knowledge transfer directly impacts customer and employee retention.

Red flag: Seller unwilling to commit to more than 30 days of post-close transition support, particularly when owner-customer relationships are material to revenue.

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Review any vendor supply agreements, distributor relationships, or preferred pricing arrangements with HVAC equipment suppliers

Established relationships with regional distributors (Wesco, Ferguson, Johnstone Supply) can provide pricing advantages and credit terms that take years to replicate.

Red flag: Supply accounts in the owner's personal name rather than the business entity — potentially non-transferable without supplier approval.

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Evaluate marketing channels — Google Local Services Ads, SEO, Angi, referral programs — and assess lead source attribution

Understanding where new customers originate allows the buyer to protect and scale working marketing channels immediately post-close rather than starting from scratch.

Red flag: All new customer acquisition is driven by the owner's personal network or word-of-mouth with no scalable, documented marketing channel in place.

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Confirm any manufacturer certifications — Carrier Factory Authorized Dealer, Trane Comfort Specialist, etc. — and their transferability

Manufacturer dealer programs provide access to premium equipment pricing, co-op marketing funds, and warranty labor reimbursement. They are revenue-relevant and may require reapplication under new ownership.

Red flag: Manufacturer dealer status is non-transferable or requires new application under buyer ownership — creating a gap in equipment access or warranty work eligibility.

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Deal-Killer Red Flags for HVAC

  • Owner is the sole qualifying HVAC contractor licensee with no licensed technician on staff capable of holding the qualifier role post-close — the business cannot legally operate after the seller departs
  • Fewer than 25 active, written maintenance service agreements for a business claiming 'strong recurring revenue' — indicating the maintenance book is overstated and revenue is predominantly break-fix
  • Any single customer — commercial property management company, HOA, or general contractor — accounting for more than 20% of total annual revenue with no written, transferable service contract
  • Tax returns showing materially lower revenue than internal P&L for 2 or more years, with the seller attributing the difference to uncategorized cash receipts or personal expense pass-throughs
  • Technicians classified as 1099 independent contractors performing regular, scheduled work — creating IRS misclassification exposure and workers' compensation liability that survives an asset purchase
  • Active or pending disciplinary complaint with the state contractor licensing board, or EPA notice of violation related to refrigerant handling or disposal — creating regulatory and financing blockers
  • Fleet averaging 150,000+ miles with no vehicle maintenance records and deferred repairs visible on walkthrough — signaling $150K–$400K in near-term capex not reflected in the deal price
  • Seller unwilling to commit to a meaningful post-close transition period (90+ days) in a business where the owner personally manages dispatch, sales, and key commercial customer relationships

Frequently Asked Questions

How many maintenance agreements should an HVAC business have before I consider it acquisition-worthy?

As a floor, look for at least 50 active, written maintenance service agreements before taking a business seriously. For a business in the $1M–$2M revenue range, 100–200 agreements is a more realistic target. At $3M–$5M revenue, you should see 300–600+ active contracts. The count matters less than the quality — verify renewal rates above 80%, confirm agreements are written and assignable, and reconcile the stated monthly recurring revenue against actual bank deposits before accepting the seller's MRR figure.

What happens to the HVAC contractor license when the business is sold?

It depends on your state. In most states, an HVAC contractor license is held by a qualifying individual — often the owner — and does not automatically transfer to a new owner in an asset sale. You have three options: hire a licensed qualifier who will remain post-close, have the seller retain a consulting role while you obtain your own license, or negotiate a transition period long enough for you to obtain a qualifying license in the state. This is a day-one operational risk — if the seller's license lapses and no qualifier is in place, the business cannot legally operate. Confirm the state's licensing rules with a local attorney before signing a LOI.

How do I evaluate whether HVAC technicians will stay after I buy the business?

Start by understanding why they joined and why they've stayed. Review tenure, compensation relative to local market rates, and benefits. Have the seller conduct warm introductions before close where possible. Then look for structural retention risks: technicians paid below market, no health insurance or retirement plan, or a strong personal loyalty to the owner that hasn't been extended to the business brand. Consider building retention bonuses into the deal structure — funded from the seller note or earnout — that vest 12–18 months post-close. Losing a licensed lead technician in month three can cost $60K–$100K to replace when you factor in recruiting, training, and lost productivity.

Can I use an SBA 7(a) loan to buy an HVAC business?

Yes — HVAC businesses are among the most SBA-eligible service business acquisitions due to their essential services profile, asset base, and recurring revenue characteristics. SBA 7(a) loans can cover 80–90% of the purchase price, with buyers typically injecting 10% equity and using a seller note for the remainder. The lender will require 3 years of business tax returns, a business valuation, proof of licensing continuity, and evidence of sufficient cash flow to service debt. Businesses with strong maintenance agreement MRR and documented SDE above $300K are typically well-positioned for SBA approval. Work with an SBA lender experienced in trades business acquisitions — not every community bank understands HVAC-specific cash flow dynamics.

What is a fair valuation multiple for an HVAC business with maintenance contracts?

HVAC businesses with a strong recurring maintenance base typically trade at 3x–5.5x SDE or EBITDA in the lower middle market. A business with 200+ active maintenance contracts, renewal rates above 85%, licensed staff independent of the owner, and clean financials can command the upper end of that range. A break-fix-heavy business with minimal maintenance agreements, owner-dependent operations, and an aging fleet will trade at the low end — 2.5x–3.5x — if it sells at all. The maintenance contract book is the single biggest multiple driver: buyers are paying for predictable, recurring cash flow, not just trailing revenue.

What should I look for in the fleet during HVAC due diligence?

Request a complete fleet inventory with year, make, model, mileage, and title for every vehicle. Vehicles should be titled in the business name — personally titled vehicles complicate the asset transfer. For any vehicle over 100,000 miles, request maintenance records and consider a pre-purchase mechanical inspection. Build a 36-month fleet replacement budget into your post-close financial model: assume $45K–$75K per replacement service van depending on upfit requirements. A fleet of 8 vans averaging 130,000 miles isn't a deal-killer, but it is a known capital requirement that should be reflected in your offer price or seller note terms.

How does seasonal cash flow affect working capital needs at close?

HVAC revenue peaks in summer (cooling) and winter (heating) with shoulder-season slowdowns in spring and fall. If you close the acquisition in September or October, you may be buying into 60–90 days of lower revenue before the heating season ramps. Work with your SBA lender to model monthly cash flow projections, not just annual averages. Negotiate for adequate working capital at close — ideally 60–90 days of operating expenses in the account — and consider a working capital peg in the purchase agreement so you're not buying a business that has already drawn down its cash ahead of close. Maintenance agreement prepayments collected in advance are a partial buffer but don't eliminate the seasonal cash flow challenge.

What due diligence should I do on the seller's add-backs before accepting the stated SDE?

Every add-back must be supported by documentation and tested for recurrence. Common legitimate add-backs in HVAC include: owner salary above what a replacement manager would cost, personal vehicle expenses run through the business, owner health insurance, personal cell phones, and one-time legal or accounting fees. Common illegitimate or inflated add-backs include: vehicles the new owner will still need to lease, below-market rent to an owner-affiliated LLC that will continue, and revenue from one-time equipment sales unlikely to repeat. Request the actual line items from QuickBooks or the accounting software for each add-back and verify them against bank statements. If the seller cannot produce line-level support for an add-back, exclude it from your valuation calculation.

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