Due Diligence for HVAC Acquisitions

Due Diligence Is Your Insurance Policy

I ran an HVAC company for twenty-seven years before I sold it. During that time I watched at least a dozen acquisitions happen in my market. Some of those buyers are still thriving. A few of them lost everything. And the single biggest difference between the two groups was not how much they paid or how they financed the deal. It was whether they did real due diligence or just went through the motions.

Due diligence is the phase where you stop trusting what the seller tells you and start verifying it yourself. Every number gets checked. Every contract gets read. Every van gets inspected. Every employee gets talked to. It is tedious, expensive, and absolutely non-negotiable.

Here is what I tell every buyer who asks me for advice: the seller is not your enemy, but the seller is also not your financial advisor. They have every incentive to present their business in the best possible light. They are not lying to you, at least not usually. But they are naturally going to emphasize the good and minimize the bad. Your job during due diligence is to find the bad before you sign on the dotted line.

Think about it this way. You would not buy a house without an inspection. You would not buy a used car without a mechanic looking at it. But people routinely buy million-dollar businesses based on a few tax returns and a handshake. That is how fortunes get lost.

The due diligence period typically runs 30 to 90 days after you sign the letter of intent. During that time, you have the right to examine every aspect of the business. If you find something that materially changes the deal, you can renegotiate the price, restructure the terms, or walk away entirely. That is the whole point. This is your last chance to protect yourself before you are legally and financially committed.

"I once saw a buyer skip the fleet inspection and inherit twelve vans that needed transmissions within six months. That was a $96,000 surprise he never recovered from."

Let me walk you through every area you need to examine, in the order that matters most.

Customer Contracts and Revenue Quality

The single most important thing you are buying when you acquire an HVAC company is not the equipment, not the vans, not even the brand. It is the customer base. And not all customer bases are created equal.

You need to understand exactly what kind of revenue this business generates and how sticky that revenue actually is. There are three basic categories of HVAC revenue, and each one has a very different value:

Recurring Revenue: The Gold Standard

Maintenance contracts, service agreements, planned replacement programs. These are customers who pay a fixed monthly or annual fee for regular service. In a well-run HVAC company, recurring revenue should represent 30 to 50 percent of total revenue. This is the most valuable revenue because it is predictable, it does not depend on the weather, and it comes with built-in customer retention.

When you review maintenance contracts, pay attention to these details:

• Contract terms and renewal rates. Are these auto-renewing? What is the historical renewal rate? Anything above 80 percent is strong. Below 60 percent is a red flag.
• Pricing adequacy. Some sellers lock in low prices to keep customer counts high. If the contracts are priced below market, you will inherit unprofitable work.
• Service scope. What exactly is included? Some contracts promise parts and labor, which means every service call eats into your margin.
• Assignment clauses. Can these contracts be transferred to a new owner? If the contract is between the customer and the seller personally, you may not inherit it at all.

Demand Service: Profitable but Volatile

Break-fix calls, emergency repairs, system troubleshooting. This is the bread and butter of most HVAC companies. It is profitable work, but it is inherently unpredictable. A mild summer or a warm winter can cut demand service revenue by 20 to 30 percent in a single season.

Look at demand service revenue across at least three years to understand the seasonal patterns and year-over-year trends. One great year does not mean the business is growing. It might just mean last summer was brutal.

Installation and Project Revenue: High Margin, Low Predictability

New system installations, commercial buildouts, equipment replacements. This is often the highest-margin work, but it is also the least predictable. A single large commercial project can represent 15 to 20 percent of annual revenue. When that project ends, there is a hole in the numbers.

Request a full customer list with revenue by customer for the past three years. Sort it by revenue. The pattern will tell you everything you need to know about the health and sustainability of this business. If the top ten customers are shrinking while the long tail is growing, that is actually a good sign. It means the business is diversifying. If the top ten are growing but the small customers are disappearing, the company is becoming dangerously dependent on a few accounts.

Also request copies of every active service agreement. Read them. All of them. I know that sounds painful, but you need to understand exactly what obligations you are inheriting. I once reviewed a company that had 180 maintenance contracts, and forty of them included free emergency service calls. That was a ticking time bomb the seller never mentioned.

The Fleet: Your Most Expensive Asset (Or Liability)

After the customer base, the vehicle fleet is probably the most important physical asset in an HVAC company. Your technicians live in those vans. The vans carry the inventory, the tools, and the brand. And a fleet in bad condition will drain your cash flow faster than almost any other problem you can inherit.

I have seen this go wrong more times than I can count. The seller shows you a row of clean, wrapped vans in the parking lot and you think the fleet looks great. What you did not see is that half of those vans have 180,000 miles on them, the transmissions are slipping, the A/C does not work, and the shelving inside is held together with zip ties.

What to Inspect on Every Vehicle

For each vehicle in the fleet, you need the following information:

• Year, make, model, and mileage. Anything over 150,000 miles on a work van is approaching end of life. Budget $45,000 to $55,000 per replacement van, fully upfitted.
• Maintenance records. Regular oil changes? Transmission service? Brake replacements? If there are no records, assume the worst.
• Title status. Are the vehicles owned outright or leased? If leased, are the leases assignable? What are the remaining payments?
• Condition assessment. Have an independent mechanic inspect every vehicle. Yes, every single one. This is not where you cut corners.
• Tool and equipment inventory. What recovery machines, gauges, vacuum pumps, and specialty tools are in each van? Get a complete inventory.

"A fleet of eight vans that all need replacement in the same two-year window is not a fleet. It is a $400,000 capital expenditure that the seller did not tell you about."

Fleet Age Distribution Matters

The ideal fleet has a staggered age distribution. You want some newer vans, some mid-life vans, and maybe one or two that are approaching replacement. This spreads out the capital expenditures over time. What you do not want is a fleet where every vehicle was purchased in the same year, because they will all need replacement at the same time.

Create a spreadsheet with every vehicle, its current condition, and an estimated remaining useful life. Then calculate the total fleet replacement cost you will face in the first three years of ownership. That number needs to be part of your acquisition financial model. If the seller priced the business assuming the fleet was worth book value, but the actual replacement cost is $200,000 more than book value, that difference needs to come off the purchase price.

Licensing, Insurance, and Compliance

This is the section that makes most buyers' eyes glaze over. And that is exactly why it catches people by surprise. Licensing and compliance issues can literally shut down your business on day one if you are not prepared.

HVAC licensing requirements vary dramatically by state, and sometimes by county or city. In some states, the company holds the license. In other states, the license belongs to an individual — the qualifying agent. If the seller is the qualifying agent and they are walking away from the business, you may not have a valid license to operate.

State and Local Licensing

• Who holds the contractor license? The business entity or the individual owner? This is the first question you need answered.
• Is the license transferable? In many states, you will need to apply for a new license. That process can take weeks or months.
• Do you personally qualify? Many states require the qualifying agent to have specific certifications, years of experience, or to pass a trade exam.
• EPA Section 608 certifications. Every technician who handles refrigerants must be EPA certified. Get a list of every employee's certification status and expiration dates.
• Local business licenses and permits. These often need to be reapplied for under new ownership. Check every jurisdiction where the company operates.

Insurance Coverage Gaps

Request complete copies of every insurance policy the company carries. Then have your own insurance agent review them. You are looking for:

• General liability. What are the limits? Are they adequate for the type of work the company performs? Commercial HVAC work typically requires higher limits than residential.
• Workers' compensation. Is it current? What is the experience modification rate (EMR)? A high EMR means a history of workplace injuries, which means higher premiums for you going forward.
• Commercial auto. Does it cover all vehicles? What about personal vehicles used for company business?
• Professional liability (errors and omissions). This covers faulty installations and design errors. Not every HVAC company carries it, but if the company does commercial design-build work, it is essential.
• Umbrella policy. For a company doing commercial work, an umbrella policy of $1 million to $5 million is standard.

Also check for any open insurance claims. An active claim can affect your ability to get coverage or dramatically increase your premiums. Ask the seller directly, and then verify with the insurance carrier.

Environmental and Safety Compliance

HVAC companies handle refrigerants, which are regulated substances. Check for compliance with EPA regulations on refrigerant handling, recovery, and record-keeping. If the company has been sloppy about tracking refrigerant purchases and disposals, you could inherit fines ranging from $37,500 to $97,500 per day per violation under the Clean Air Act.

Also review OSHA compliance. Has the company had any OSHA inspections or citations? Is there a written safety program? Are there fall protection procedures for rooftop work? This is not just about avoiding fines. It is about protecting your employees and your liability exposure.

Employee Retention: Will the Team Stay?

You can buy the customer list, the vans, the brand, and the phone number. But if the technicians walk out the door the week after closing, you have bought an empty shell. In the current labor market, replacing a skilled HVAC technician can take three to six months and cost $8,000 to $15,000 in recruiting, training, and lost productivity. Replacing your entire team would be catastrophic.

Employee retention is one of the most underestimated risks in any HVAC acquisition. And it is one of the hardest to evaluate because you typically cannot talk to the employees until late in the due diligence process, if at all, before the deal is announced.

Identifying Key Employees

Not all employees carry equal risk. Identify the key people whose departure would materially hurt the business:

• Lead technicians who handle the most complex service calls and have deep relationships with major commercial accounts.
• The office manager or dispatcher who actually runs the day-to-day operations and knows where everything is.
• Sales staff who bring in new installation business and manage key account relationships.
• Any employee with specialized certifications that are hard to replace, such as controls programming, commercial refrigeration, or building automation.

"The dispatcher who has been there for fifteen years knows more about the daily operations than the owner does. Lose her and you lose the institutional memory of the entire company."

Compensation and Benefits Analysis

Request a complete compensation breakdown for every employee. Compare it to market rates in your area. You are looking for two scenarios, both of which are problems:

Also look at benefits. Does the company offer health insurance, retirement matching, paid time off, company vehicles for personal use? If so, those are obligations you are inheriting. If not, you may need to add them to retain talent in a competitive market.

Non-Competes and Employment Agreements

Review every employment agreement and non-compete clause. Key questions:

• Do the non-competes actually survive a change of ownership? In many states, they do not.
• Are the non-competes enforceable in your state? Several states have severely limited or banned non-competes for hourly employees.
• Is there a key employee who could leave, start a competing company, and take major customers with them? If so, you need a retention agreement signed before closing.

The best approach I have seen is for the buyer to meet individually with every key employee within the first week after the deal is announced. Be honest about your plans. Ask them what they need to stay. Listen more than you talk. Most employees are nervous about change, not opposed to it. If you can reduce their uncertainty, most of them will stay.

Online Reputation and Review Health

This is the section that surprises most buyers because they do not think of online reviews as a due diligence item. But in 2026, your Google Business Profile is arguably the most important marketing asset an HVAC company owns. And unlike a van or a piece of equipment, you cannot just replace it if it is damaged.

Here is what you need to examine:

Google Business Profile

• Overall rating. Anything below 4.2 stars is a problem. Below 3.8 and you are fighting an uphill battle for every new customer.
• Review volume. A company with 400 reviews and a 4.5 rating is in a much stronger position than a company with 15 reviews and a 4.8 rating.
• Review recency. Are they still getting reviews regularly? A gap in reviews can signal a decline in customer satisfaction or a loss of review generation processes.
• Response to negative reviews. How does the company handle complaints? Professional responses to negative reviews matter as much as the reviews themselves.
• Profile ownership. Who controls the Google Business Profile? Is it the owner, a marketing agency, or a former employee? You need to ensure transfer of ownership is possible and planned.

Other Review Platforms

Check Yelp, BBB (Better Business Bureau), Angi, HomeAdvisor, and any industry-specific platforms. Look for patterns across all platforms. A company with great Google reviews but terrible BBB complaints may be cherry-picking where they send happy customers while ignoring the rest.

Also search for the company name in local news, forums, and social media. You want to know if there have been any public complaints, legal disputes, or news coverage that could affect the brand. A single viral negative post can take months to overcome.

The transfer of the Google Business Profile should be explicitly addressed in the purchase agreement. It is one of the most valuable digital assets in the deal, and it is often overlooked until after closing when someone realizes the former owner still controls it.

Deferred Maintenance and Hidden Liabilities

Sellers who are planning to exit a business often stop investing in it during the last two or three years before the sale. They defer maintenance on the building. They skip equipment upgrades. They reduce marketing spend. They stretch the useful life of everything because every dollar they do not spend is a dollar that shows up as profit on the financials you are reviewing.

This is not dishonest. It is human nature. But it means you need to look beyond the profit and loss statement and examine the physical condition of everything the business owns and occupies.

Building and Facilities

If the business owns or leases a building, inspect it the same way you would inspect a house you were buying:

• Roof condition. Especially relevant for HVAC companies that often have warehouse space. A roof replacement can cost $100,000 or more.
• HVAC systems in the building itself. The irony of an HVAC company with broken HVAC is not lost on anyone, but it happens more often than you would think.
• Plumbing, electrical, and fire suppression. When was the last inspection? Are there code violations?
• Environmental issues. For older buildings, check for asbestos, lead paint, and underground storage tanks. Environmental remediation can cost hundreds of thousands of dollars.

Warranty Obligations

This is a big one that many buyers miss. If the company installed equipment over the past five to ten years, there may be active warranties on that equipment. Those warranties come with obligations. If a system the company installed three years ago fails, you may be on the hook for the labor to replace it under the manufacturer's warranty, or under the company's own installation guarantee.

"The seller had installed 200 heat pump systems in the last two years with a five-year parts and labor warranty. That was $300,000 in potential warranty liability sitting on the books as zero."

Request a complete list of all warranty obligations, including:

• Manufacturer warranties on installed equipment (and whether they are properly registered)
• Company-provided labor warranties on installations
• Extended warranty programs sold to customers
• Any warranty claims currently in process

Pending Legal Issues

Ask the seller directly about any pending or threatened litigation, and then verify with a litigation search. Check for:

• Customer lawsuits for faulty installation or property damage
• Employee disputes, wage claims, or workers' compensation cases
• Subcontractor liens or payment disputes
• Tax liens or unpaid obligations
• Regulatory actions or pending fines

The 47-Point HVAC Due Diligence Checklist

After twenty-seven years in this industry and watching more acquisitions than I can count, I have distilled everything into this comprehensive checklist. Print it. Use it. Check off every single item before you close.

Financial and Tax (Items 1 - 10)

• Three years of tax returns (federal, state, and local)
• Monthly profit and loss statements for the trailing 24 months
• Balance sheet as of the most recent month-end
• Accounts receivable aging report (current, 30, 60, 90+ days)
• Accounts payable aging report
• Bank statements for the trailing 12 months
• Credit card statements for the trailing 12 months
• Revenue by customer report (top 50 customers, 3 years)
• Revenue by service type (maintenance, repair, install, commercial, residential)
• Verification that all payroll taxes, sales taxes, and withholdings are current

Customer Contracts (Items 11 - 17)

• Complete list of all active service and maintenance agreements
• Copies of all customer contracts with terms and renewal dates
• Historical contract renewal rates (3 years)
• Assignment clauses reviewed — confirm contracts survive ownership change
• Customer concentration analysis (no single customer over 10 percent of revenue)
• Backlog of signed but uncompleted installation projects
• Pending proposals and estimated close rates

Fleet and Equipment (Items 18 - 25)

• Complete vehicle list with year, make, model, VIN, mileage, and title status
• Vehicle maintenance records for each unit
• Independent mechanical inspection of every vehicle
• Lease agreements for any leased vehicles (terms, assignability, buyout)
• Tool and equipment inventory for each van
• Recovery machine certifications and calibration dates
• Warehouse inventory count and valuation
• Fleet replacement schedule and three-year capital expenditure projection

Licensing and Compliance (Items 26 - 33)

• State HVAC contractor license (holder, transferability, expiration)
• Local business licenses and permits for all operating jurisdictions
• EPA Section 608 certifications for all technicians
• Refrigerant tracking and disposal records (EPA compliance)
• OSHA compliance history and any outstanding citations
• General liability insurance policy (limits, exclusions, claims history)
• Workers' compensation policy and experience modification rate
• Commercial auto insurance covering all vehicles

Employees and HR (Items 34 - 40)

• Complete employee roster with hire dates, roles, certifications, and compensation
• Employment agreements and non-compete clauses reviewed by attorney
• Compensation benchmarked against local market rates
• Benefits summary (health, retirement, PTO, vehicle perks)
• Employee turnover rate for the past three years
• Key employee retention plan and budget (bonuses, agreements)
• Pending HR complaints, disputes, or legal claims

Reputation and Digital Assets (Items 41 - 44)

• Google Business Profile rating, review count, and response quality
• BBB rating, Yelp, Angi, and HomeAdvisor review audit
• Website ownership, domain registration, and hosting access confirmed
• Social media account access and ownership transfer plan

Facilities and Liabilities (Items 45 - 47)

• Building inspection (roof, HVAC, plumbing, electrical, environmental)
• Complete warranty obligation inventory (manufacturer and company-provided)
• Litigation search and seller's written representations on undisclosed liabilities

Due diligence is not glamorous. It is not exciting. But it is the single most important thing you will do during the entire acquisition process. Do it right and you will buy a business with your eyes open, knowing exactly what you are getting and what it is worth. Skip it or rush through it and you are rolling the dice with your life savings.

Take your time. Hire the right professionals. Check every box. Your future self will thank you.