[Form 4] Comfort Systems USA, Inc. Insider Trading Activity

Rhea-AI Filing Summary

William J. Sandbrook, a director of Comfort Systems USA, Inc. (FIX), reported sales of Company common stock on September 9-10, 2025. The Form 4 discloses three sale transactions totaling 1,500 shares: 600 shares sold at an average price reported as $708.97, 100 shares sold at $706, and 800 shares sold at $733.5583. After these transactions the reporting person beneficially owned 11,666 shares, which includes 170 shares held indirectly. The filing was signed by an attorney-in-fact on September 10, 2025. The Form 4 indicates the filer is a Company director and was filed by one reporting person. No options, grants, or derivative transactions are reported.

Positive

• None.

Negative

• Insider sales totaling 1,500 shares reduced the reporting person's beneficial ownership to 11,666 shares.
• No stated reason for the sales is provided in the Form 4, limiting context for investors.

Insights

Securities Analyst

TL;DR: Director sold 1,500 shares across three transactions, lowering direct holdings to 11,666 shares; no derivatives reported.

The reported insider activity consists solely of open-market sales executed over two days for a total of 1,500 shares. The sale prices reported in the Form 4 entries range roughly from $706 to $733.56, and the filing shows the director remains a shareholder with 11,666 total shares after the transactions. The disclosure is routine for Section 16 reporting: it records the amounts, prices, and resulting beneficial ownership without indicating any change in role or derivative exposure. Impact for investors is informational rather than transformational because no material corporate event, grants, or changes in control are disclosed.

Corporate Governance Expert

TL;DR: Director-level insider sales occurred; filings appear complete for reported transactions and show continued ownership.

The Form 4 identifies the reporting person as a director and documents the disposition of common stock on 09/09/2025 and 09/10/2025. Post-transaction beneficial ownership is reported and the filing was executed by an attorney-in-fact. The report does not include any amendments, option exercises, or related-party transfers. From a governance perspective, the disclosure meets Section 16 requirements by listing transaction dates, amounts sold, prices, and resulting holdings. There is no indication in the filing of any corporate governance action or event tied to these sales.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

SANDBROOK WILLIAM J

(Last) (First) (Middle)

C/O COMFORT SYSTEMS USA, INC.

675 BERING DRIVE, SUITE 400

(Street)

HOUSTON TX 77057

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
COMFORT SYSTEMS USA INC [ FIX ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
09/09/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	09/09/2025		S		600	D	$708.97(1)	12,566(2)	D
Common Stock	09/09/2025		S		100	D	$706(1)	12,466(2)	D
Common Stock	09/10/2025		S		800	D	$733.5583(1)	11,666(2)	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Represents the average price of shares sold; full information regarding the number of shares sold and specific prices will be made available upon request to the Company's Office of the General Counsel.

2. Shares held directly by the Reporting Person, including 170 shares held indirectly by the Reporting Person.

	/s/ Rachel R. Eslicker, Attorney-in-Fact	09/10/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

How many shares did William J. Sandbrook sell according to the Form 4 for FIX?

The Form 4 reports sales totaling 1,500 shares (600, 100, and 800 shares) on 09/09/2025 and 09/10/2025.

What prices were reported for the insider sales in the FIX Form 4?

The filing lists prices of $708.97 (average for 600 shares), $706 (100 shares), and $733.5583 (800 shares).

How many shares does the reporting director own after the transactions?

After the reported transactions the director beneficially owned 11,666 shares, including 170 shares held indirectly.

What is William J. Sandbrook's relationship to Comfort Systems USA, Inc. (FIX)?

The Form 4 identifies William J. Sandbrook as a director of the issuer.

Did the Form 4 report any derivative transactions or option exercises for FIX?

No. Table II for derivative securities contains no reported transactions; only common stock sales are disclosed.

Does the Form 4 state why the shares were sold?

The filing does not state a reason for the sales.