UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K/A

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934

Date of Report (date of earliest event reported):  July 28, 2010

Commission File Number:  1-13011

COMFORT SYSTEMS USA, INC.

(Exact name of registrant as specified in its charter)

675 Bering Drive

Suite 400

Houston, Texas 77057

(Address of Principal Executive offices) (Zip Code)

Registrant’s telephone number, including area code:  (713) 830-9600

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

o            Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o            Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o           Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o            Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Explanatory Note:

As previously reported in a Current Report on Form 8-K filed on July 30, 2010 (the “Initial Form 8-K”), Comfort Systems USA, Inc. (the “Company”) entered into a stock purchase agreement (the “Stock Purchase Agreement”), dated July 28, 2010, to purchase all of the issued and outstanding stock of ColonialWebb Contractors Company, a Virginia corporation (“ColonialWebb”). As a result of the acquisition, ColonialWebb is a wholly-owned subsidiary of the Company.  This Amendment No. 1 on Form 8-K/A amends and supplements the Initial Form 8-K to include financial statements and pro forma financial information required pursuant to Item 9.01 of Form 8-K.

Item 9.01        Financial Statements and Exhibits

(a)                                 Financial statements of businesses acquired

The audited financial statements for ColonialWebb as of December 31, 2008, including the related independent auditors’ report, are included as Exhibit 99.2 hereto.

The audited financial statements for ColonialWebb as of December 31, 2009, including the related independent auditors’ report, are included as Exhibit 99.3 hereto.

The unaudited financial statements for ColonialWebb as of June 30, 2010 are included as Exhibit 99.4 hereto.

(b)                                 Pro forma financial information

The following unaudited pro forma condensed combined balance sheet combines the historical consolidated balance sheet of the Company and the historical balance sheet of ColonialWebb, giving effect to the acquisition as if the acquisition had been consummated on June 30, 2010.  The unaudited pro forma condensed combined statements of operations for the year ended December 31, 2009 and the six months ended June 30, 2010 combine the historical consolidated statements of operations of the Company and the historical statements of operations of ColonialWebb, giving effect to the acquisition as if it had occurred on January 1, 2009.  The unaudited pro forma adjustments to reflect the purchase price allocation are based upon preliminary information, which may be revised as additional information becomes available.

The notes to the unaudited pro forma condensed combined financial statements provide a more detailed discussion of how such adjustments were derived and presented in the pro forma financial statements.  The accompanying unaudited pro forma condensed combined financial statements have been compiled from historical financial statements and other information as described herein, but do not purport to represent what the Company’s financial position or results of operations actually would have been had the transactions occurred on the dates indicated herein, or project the Company’s performance for any future periods.  Historically, the construction industry has been highly cyclical and, specifically, the HVAC industry is subject to seasonal variations.

The pro forma financial information should be read in conjunction with the Company’s historical financial statements included in its Form 10-K for the year ended December 31, 2009 and Form 10-Q for the period ended June 30, 2010.

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Comfort Systems USA, Inc.

Pro Forma Condensed Combined Balance Sheet

As of June 30, 2010

(in thousands)

(Unaudited)

The accompanying notes are an integral part of this financial statement.

2

Comfort Systems USA, Inc.

Pro Forma Condensed Combined Statement of Operations

Six Months Ended June 30, 2010

(in thousands, except per share amounts)

(Unaudited)

The accompanying notes are an integral part of this financial statement.

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Comfort Systems USA, Inc.

Pro Forma Condensed Combined Statement of Operations

Year Ended December 31, 2009

(in thousands, except per share amounts)

(Unaudited)

The accompanying notes are an integral part of this financial statement.

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NOTES TO UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL STATEMENTS

1.              Purchase Price Allocation

The allocation of the purchase price to the assets acquired and liabilities assumed is preliminary and, therefore, subject to change.  The allocation of the purchase price was prepared based on the information available as of the acquisition date and, therefore, may be materially impacted by certain adjustments on the finalization of the fair value assessments of ColonialWebb’s assets and liabilities.

The following is the unaudited pro forma purchase price and the unaudited pro forma purchase price allocation based on ColonialWebb’s unaudited June 30, 2010 balance sheet (in thousands):

2.              Pro Forma Adjustments

The accompanying pro forma condensed combined financial statements give effect to the following pro forma adjustments necessary to reflect the acquisition outlined in the preceding introduction as if the transaction occurred on January 1, 2009 in the pro forma condensed combined statement of operations and on June 30, 2010 in the pro forma condensed combined balance sheet:

(A)       Purchase price paid from cash, including the cash paid for excess working capital as of June 30, 2010.

(B)       Additional consideration payable in the form of notes issued to the former owners and contingent earn-out payments associated with the achievement of specified milestones.  Contingent earn-out payments are recorded at their estimated fair value determined based on a probability-weighted income approach.  This fair value measurement is based on significant unobservable inputs in the market and thus represents a Level 3 measurement within the fair value hierarchy.  Future changes in the estimated fair value of the contingent payments will be recognized immediately in earnings.

(C)       Fair value adjustments to assets and liabilities acquired, which includes $3.1 million to property and equipment, $49.7 million to goodwill, $28.1 million to intangible assets (see note 3), $0.3 million to accrued self insurance expense, and $0.2 million to other current liabilities.

(D)       Adjustments to reflect the addition of deferred income taxes related to acquired assets and liabilities and the conversion of ColonialWebb from an S-Corp to a C-Corp.

(E)        Adjustment to conform the accounting for deferred compensation with the Company’s accounting policy.

(F)         Elimination of ColonialWebb’s pre-existing stockholders’ equity balances due to change in ownership.

(G)       Amortization of preliminary fair value amounts allocated to definite-lived intangible assets over the preliminary estimated useful lives.  (See note 3 for further details.)

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(H)      Elimination of the Company’s interest income associated with the utilization of cash for the transaction.

(I)           Interest expense incurred on the notes to former owners.

(J)           Depreciation expense incurred on the step-up of the property and equipment to fair value.

3.              Identifiable Intangible Assets

The preliminary components of identifiable intangible assets resulting from the acquisition and their related amortizable lives are as follows (dollars in thousands):

These components are subject to change based upon the results of a third party valuation of the identifiable intangible assets.  The estimated value of the backlog, trade names, and non-compete agreements are being amortized using the straight line method of accounting over their estimated amortization lives.  The estimated value of the customer relationships is being amortized using the expected future cash flows that reflect the expected economic benefit.

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(d)           Exhibits

The following exhibits are included herein:

10.1 Stock Purchase Agreement, dated July 28, 2010 (incorporated by reference to Exhibit 10.1 of the Company’s Current Report on Form 8-K filed on July 30, 2010).

23.1 Consent of Keiter, Stephens, Hurst, Gary & Shreaves, P.C.

99.1 Press release dated July 28, 2010 (i) announcing the Company’s acquisition of ColonialWebb and (ii) discussing the Company’s second quarter earnings (incorporated by reference to Exhibit 99.1 of the Company’s Current Report on Form 8-K filed on July 30, 2010).

99.2 The audited financial statements for ColonialWebb as of December 31, 2008, including the related independent auditors’ report.

99.3 The audited financial statements for ColonialWebb as of December 31, 2009, including the related independent auditors’ report.

99.4 The unaudited financial statements for ColonialWebb as of June 30, 2010.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date:  October 6, 2010

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Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

The Board of Directors
Comfort Systems USA, Inc.

We hereby consent to the incorporation by reference in this Current Report on Form 8-K/A of Comfort Systems USA, Inc. of our reports dated March 8, 2010 and March 17, 2009 relating to the financial statements of ColonialWebb Contractors Company as of December 31, 2009 and 2008, respectively.

/s/ Keiter, Stephens, Hurst, Gary & Shreaves, PC

October 4, 2010

Glen Allen, Virginia

Exhibit 99.2

Financial Statements

December 31, 2008

COLONIALWEBB CONTRACTORS COMPANY

Table of Contents

REPORT OF INDEPENDENT ACCOUNTANTS

To the Board of Directors and Stockholders

ColonialWebb Contractors Company

2820 Ackley Avenue

Richmond, VA 23228

We have audited the accompanying balance sheet of ColonialWebb Contractors Company (the “Company”) as of December 31, 2008, and the related statements of income, stockholders’ equity, and cash flows for the year then ended. These financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on these financial statements based on our audit.

We conducted our audit in accordance with auditing standards generally accepted in the United States. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement.  An audit includes examining on a test basis, evidence supporting the amounts and disclosures in the financial statements.  An audit also includes assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall financial statement presentation.  We believe that our audit provides a reasonable basis for our opinion.

In our opinion, the financial statements referred to above present fairly, in all material respects, the financial position of ColonialWebb Contractors Company as of December 31, 2008, and the results of its operations and its cash flows for the year then ended in conformity with

March 17, 2009

COLONIALWEBB CONTRACTORS COMPANY

Balance Sheet

December 31, 2008

See accompanying notes to financial statements.

2

COLONIALWEBB CONTRACTORS COMPANY

Statement of Income

For the Year Ended December 31, 2008

See accompanying notes to financial statements.

3

COLONIALWEBB CONTRACTORS COMPANY

Statement of Stockholders’ Equity

For the Year Ended December 31, 2008

See accompanying notes to financial statements.

4

COLONIALWEBB CONTRACTORS COMPANY

Statement of Cash Flows

For the Year Ended December 31, 2008

See accompanying notes to financial statements.

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COLONIALWEBB CONTRACTORS COMPANY

Notes to Financial Statements

1.                                      Summary of Significant Accounting Policies:

Nature of Business:  ColonialWebb Contractors Company (the “Company”), was incorporated in the Commonwealth of Virginia in 1972.  The Company operates as a comprehensive, single-source construction, service, manufacturing and refrigeration service firm servicing the Mid-Atlantic region.  Headquartered in Richmond, VA with seven other locations, the Company has approximately 1,200 employees and a fleet of over 500 service vehicles.

Revenue and Cost Recognition:  Revenues from fixed-price construction contracts are recognized on the percentage of completion method, measured by total cost incurred to total estimated cost.  Revenues from cost-plus-fee contracts are recognized on the basis of costs incurred during the period plus the fee earned, measured by the cost-to-cost method.

Contracts to service heating, ventilation and air conditioning (HVAC) systems and for building maintenance are generally for a period of one year and are recognized only to the extent earned. The revenue earned in a period is the ratable portion of the contract period and is included as a component of accrued liabilities on the balance sheet.

Contract costs include all direct material, labor, subcontract, and other direct costs and those indirect costs related to contract performance such as insurance, payroll taxes, and employee benefits.  Operating costs are charged to expense as incurred. Provision for estimated losses on uncompleted contracts are made in the period in which such losses are determined.  Changes in job performance, job conditions, and estimated profitability are recognized in the period in which the revisions are determined.

The asset, “Costs and estimated earnings in excess of billings” represents revenues recognized in excess of amounts billed.  The liability, “Billings in excess of costs and estimated earnings,” represents billings in excess of revenues recognized.

Assets and liabilities related to long-term construction contracts are included in current assets and current liabilities in the accompanying balance sheets, as they will be liquidated in the normal course of contract completion, although this may require more than one year.

Cash and Cash Equivalents:  The Company considers all highly liquid debt instruments purchased with a maturity of three months or less to be cash equivalents.

Allowance for Bad Debts:  The Company uses the reserve method of accounting for bad debts.  The allowance for doubtful accounts at December 31, 2008 was $1,348,864.

Inventory:  Inventory is stated at the lower of cost or market, with cost being determined on a first-in, first out (FIFO) basis.  Inventories principally consist of contract related materials, service parts, and supplies.  The Company evaluates inventory levels and expected usage on a periodic basis and records valuation allowances as required.

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COLONIALWEBB CONTRACTORS COMPANY

Notes to Financial Statements, Continued

1.                                      Summary of Significant Accounting Policies, Continued:

Property and Equipment:  Property and equipment is stated at cost.  The costs of major improvements are capitalized, while the costs of maintenance and repairs that do not extend the original estimated economic life are charged to expense as incurred. Depreciation and amortization are provided on the straight-line method over the estimated useful lives of the assets:

Income Taxes:  The Company has elected to have its income taxed under Section 1362 (Subchapter S Corporations) of the Internal Revenue Code, which provides that, in lieu of corporate income taxes, the stockholders are taxed on the Company’s taxable income.  Similar provisions apply for state income tax reporting.  Accordingly, no provision or liability for income taxes is provided in the accompanying financial statements.

Credit Risk:  Financial instruments which potentially subject the Company to concentrations of credit risk consist principally of cash, accounts receivable and costs and estimated earnings in excess of billings on uncompleted contracts.

The Company maintains its cash balances in one financial institution.  The balances are insured by the Federal Deposit Insurance Corporation up to $250,000.  The Company regularly has funds in excess of $250,000 in the financial institution.

Accounts receivable and costs and estimated earnings in excess of billings on uncompleted contracts result from contracts with customers principally in the Mid-Atlantic States.  The Company does not normally require collateral or perfect its lien rights with respect to contract amounts or retainage held.  Credit is extended to customers after an evaluation for credit worthiness.

For the year ended December 31, 2008, work performed for two customers, either directly or through another contractor, represented approximately 22% of total revenues.  One customer represented approximately 18% of accounts receivable.

Use of Estimates:  The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period.  Actual results could differ from those estimates.

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COLONIALWEBB CONTRACTORS COMPANY

Notes to Financial Statements, Continued

1.                                      Summary of Significant Accounting Policies, Continued:

Self-Insured Claims:  The Company insures its automobile, general liability, and workers’ compensation, claim exposures with a large deductible insurance program; and provides a self-funded group health insurance for its employees, as described in notes 11 and 12.  The total expense under these and other insurance programs was approximately $5,500,000 in 2008.

The accrued estimated liability for self-insured claims is revised for changes in the underlying assumptions.

Warranty:  The Company generally warrants labor for varying periods ranging from one year to eighteen months after installation of new HVAC systems.  The Company generally warrants labor for up to three months after the servicing of existing HVAC systems.  The Company also warrants other services offered.  A provision for the estimated warranty cost is made at the time a new system is sold and is accounted for as a component of the cost of the job.  The individual jobs are not considered 100% complete until the expiration of the negotiated warranty period.  Any warranty offered that relates to service work is expensed in the period incurred.

Advertising Costs:  Advertising costs are expensed as incurred and are included in operating expenses in the accompanying statement of income. Advertising costs were $154,479 for the year ended December 31, 2008.

Derivative Financial Instrument Policy — Interest Rate Swap:  The Company uses derivatives to manage risks related to interest rate movements.  Interest rate swap contracts designated to qualify as cash flow hedges are reported at fair value.  The gain or loss on the effective portion of the hedge initially is included as a component of other comprehensive income and is subsequently reclassified into retained earnings when interest on the related debt is paid.  The Company documents its risk management strategy and hedge effectiveness at the inception of and during the term of each hedge.  The Company’s interest rate risk management strategy is to stabilize cash flow requirements by maintaining interest rate swap contracts to convert variable-rate debt to a fixed rate.

Comprehensive income includes net income and other changes in assets and liabilities not reported in net income, but are instead reported as a separate component of stockholders’ equity.  The Company’s interest rate swap loss of ($59,052) is a component of comprehensive income, which was $17,027,839 in 2008.

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COLONIALWEBB CONTRACTORS COMPANY

Notes to Financial Statements, Continued

2.                                      Accounts Receivable:

Accounts receivable consisted of the following:

3.                                      Costs and Estimated Earnings on Uncompleted Contracts:

Costs and estimated earnings on uncompleted contracts consisted of the following:

Included in the accompanying balance sheet under the following captions:

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COLONIALWEBB CONTRACTORS COMPANY

Notes to Financial Statements, Continued

4.                                      Property and Equipment:

Property and Equipment consist of the following at December 31:

5.                                      Related Party:

The Company has entered into a two non-cancelable operating lease for office space from a limited liability company affiliated through common ownership.  The rent expense for both leases was $263,653 for 2008.

6.                                      Retirement Plan:

The Company has an employee savings/retirement plan under Section 401(k) of the Internal Revenue Code.  The plan is a salary reduction plan and allows participants to electively defer a percentage of their annual salary.  The Company’s contributions are discretionary and can be matching and/or profit sharing. Employees must also have completed at least one year of service for the Company. The Company accrued contributions of approximately $236,100 for the year ended December 31, 2008.

The Company sponsors a nonqualified, deferred compensation plan for a select group for key employees.  The deferred compensation plan has been organized in accordance with §409(a) of the Internal Revenue Code.  Under this plan, the annual Company contribution shall remain Company property until it is paid to the participant and shall be held with other Company assets. The deferred compensation plan liability was $938,218 at December 31, 2008.

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COLONIALWEBB CONTRACTORS COMPANY

Notes to Financial Statements, Continued

7.                                      Line of Credit:

The Company has a $14,000,000 credit facility which bears interest at LIBOR Market Index Rate plus 1.5% (3.4% at December 31, 2008) for any outstanding indebtedness and is due on demand.  At December 31, 2008, there were no amounts outstanding for operating debt.  The credit facility is subject to a quarterly .15% unused commitment fee.  Fees for letters of credit are determined at the time of issuance. The facility is collateralized by a first lien on accounts receivable subject to priority interest of applicable bonding companies on receivables related to bonded projects, and is guaranteed by the stockholders.

8.                                      Notes Payable:

On August 1, 2000, the Company entered into a loan agreement with the Economic Development Authority of Henrico County, Virginia related to Tax-Exempt Adjustable Mode Industrial Development Revenue bonds (IDA bonds) in the aggregate principal amount of $5,300,000. Proceeds from these bonds were used in connection with the acquisition of land and construction of an office complex and warehouse in Richmond, Virginia. The IDA bonds bear interest based on a tax-exempt variable rate (3.58% at December 31, 2008). Principal and interest installments are due quarterly and the bonds mature in August 2020.  This loan agreement was updated with an Amended and Restated Reimbursement and Security Agreement dated May 1, 2003.  The outstanding balance at December 31, 2008 was $3,400,000.

The IDA bonds are collateralized by an irrevocable letter of credit issued by Wachovia Bank as of May 1, 2003.  The letter of credit will terminate on the expiration date of the related loan agreement or as defined in the agreement.  The land, office complex and warehouse have also been pledged as collateral for amounts outstanding related to the IDA bonds.

Under the terms of the loan agreement and letter of credit, the Company is subject to various affirmative and negative covenants including the maintenance of certain financial ratios.  At December 31, 2008, management believes the Company was in compliance with these covenants.

The Company has promissory notes totaling $5,042,215 at December 31, 2008, bearing interest at rates of the 1-month London Interbank Offered Rate (LIBOR) plus 2.0% (2.43% at December 31, 2008) and LIBOR Market Index Rate plus 2.5% (4.4% at December 31, 2008) payable in monthly principal and interest installments ranging from $7,134 to $48,826 per month.  The notes are collateralized by equipment and vehicles.

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COLONIALWEBB CONTRACTORS COMPANY

Notes to Financial Statements, Continued

8.                                      Notes Payable, Continued:

Estimated principal repayments on long-term debt for future years ending December 31 are as follows: