Item 1.01 Entry into a Material Definitive Agreement. On February 23, 2026, CECO Environmental Corp., a Delaware corporation (the “ Company”), Longhorn Merger Sub, Inc., a Delaware corporation and direct wholly owned subsidiary of the Company (“ Merger Sub Inc. ”), Longhorn Merger Sub LLC, a Delaware limited liability company and direct wholly owned subsidiary of the Company (“ Merger Sub LLC”), and Thermon Group Holdings, Inc., a Delaware corporation (“ Thermon”), entered into an Agreement and Plan of Merger (the “ Merger Agreement”). Upon the terms and subject to the conditions set forth in the Merger Agreement, (i) Merger Sub Inc. will merge with and into Thermon (the “ First Merger”), with Thermon continuing as the surviving entity (the “ Surviving Corporation”), and (ii) immediately following the First Merger, the Surviving Corporation will merge with and into Merger Sub LLC (the “ Second Merger” and, together with the First Merger, the “ Mergers”), with Merger Sub LLC continuing as the surviving entity and a wholly owned subsidiary of the Company. The First Merger will become effective at a time agreed by the parties to the Merger Agreement in writing and as specified in a certificate of merger filed with the Secretary of State of the State of Delaware (the “ Effective Time”), and the Second Merger will become effective as specified in a subsequent certificate of merger (the “ Second Merger Effective Time”). Upon consummation of the Mergers and the other transactions contemplated by the Merger Agreement (the “ Transactions”), Thermon and Merger Sub Inc. will cease to exist. Under the terms of the Merger Agreement and as more fully described below, at the Effective Time, each share of common stock, par value $0.001 per share, of Thermon (“ Thermon Common Stock”), issued and outstanding immediately prior to the Effective Time (other than those shares of Thermon Common Stock excluded or constituting dissenting shares pursuant to the Merger Agreement), will be automatically converted into the right to receive from the Company, pursuant to a properly made election that has actually been received by the Exchange Agent and not revoked prior to the election deadline to be determined by the Company and Thermon (the “ Election Deadline”), and subject to the proration and allocation procedures set forth in the Merger Agreement, one of the following forms of consideration (i) a combination of 0.6840 shares of common stock, par value $0.01 per share, of the Company (“ Company Common Stock”) and $10.00 in cash (the “ Mixed Consideration”), (ii) $63.89 in cash (the “ Cash Consideration”), or (iii) 0.8110 shares of Company Common Stock (the “ Stock Consideration” and, together with the Mixed Consideration and the Cash Consideration, the “ Merger Consideration”). Under the Merger Agreement, at the Effective Time, each outstanding Thermon restricted stock unit and performance unit (a “ Thermon PU”) will be assumed by the Company and converted into a restricted stock unit award of the Company based on the Stock Consideration exchange ratio. For Thermon PUs, the number of Thermon shares underlying such award will be calculated based on target or actual performance (depending on the status of the applicable performance period), and the converted Company awards will subsequently be subject only to time-based vesting. Each outstanding Thermon stock option with an exercise price less than the Cash Consideration will be cancelled and converted into the right to receive an amount in cash equal to the Cash Consideration less the applicable exercise price, while all other Thermon stock options will be automatically cancelled for no consideration. The board of directors of the Company (the “ Company Board”) unanimously (i) determined that the Mergers and the other transactions contemplated by the Merger Agreement (the “ Transactions”) are in the best interests of, and are advisable to, the Company and its stockholders (the “ Company Stockholders”), (ii) approved and declared advisable the Merger Agreement and the Transactions, (iii) directed that the issuance of the Company Common Stock constituting the Stock Consideration to be issued in the First Merger and other shares of Company Common Stock to be issued in the Mergers or reserved for issuance in connection with the Mergers, in each case, as provided in the Merger Agreement (the “ Stock Issuance”) be submitted to the holders of the Company Common Stock for their approval and (iv) resolved to recommend that the Company Stockholders approve the Stock Issuance. At the Effective Time, the Company Board will be increased from eight to 10 members, and the newly created vacancies on the Company Board will be filled by two directors currently serving as the members of board of directors of Thermon (the “ Thermon Board” and such directors, the “ Thermon Appointees”), one of which will be designated by Thermon, in its sole discretion, and one of which will be designated by mutual agreement of the Chairman of each of the Company Board and Thermon Board. If the Transactions close prior to the Company’s 2026 annual meeting of stockholders, the Company agreed to nominate the Thermon Appointees for reelection to the Company Board at such 2026 annual meeting. The closing of the Mergers is subject to the satisfaction or waiver of certain closing conditions, including, among others, (i) adoption of the Merger Agreement by the affirmative vote of the holders of a majority of the outstanding shares of Thermon Common Stock entitled to vote thereon (the “ Thermon Stockholder Approval”), (ii) approval of the Stock Issuance by the affirmative vote of a majority of the shares of the Company Common Stock present in person or represented by proxy at a meeting of the Company Stockholders and entitled to vote thereon in accordance with the rules and regulations of the Nasdaq Stock Market LLC (“Nasdaq”), the Delaware General Corporation Law and the Company organizational documents (the “ Company Stockholder Approval”), (iii) the expiration or termination of any applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, as well as any agreement not to close embodied in a “timing agreement” between the parties to the Merger Agreement and the applicable governmental entity, (iv) no temporary restraining order, preliminary or permanent injunction or other judgment, order or decree issued by any court of competent jurisdiction being in effect, and no material law having been enacted or promulgated after the date of the Merger Agreement in any jurisdiction material to the Company and its subsidiaries, taken as a whole, or to Thermon and its subsidiaries, taken as a whole, that, in any such case, prohibits or makes illegal the consummation of the Mergers, (v) approval for listing on the Nasdaq of the shares of the Company Common Stock to be issued in the First Merger, (vi) the effectiveness of the Form S-4, (vii) the accuracy of representations and warranties and compliance with covenants of each party (in each case certain to certain qualifications) and (viii) with respect to the obligations of Thermon, the receipt of (x) a customary tax opinion of counsel to Thermon and (y) the adoption by the Company of resolutions increasing the size of the Company Board and appointing the Thermon Appointees, in each case subject to the standards set forth in the Merger Agreement.

Item 7.01 Regulation FD Disclosure. On February 24, 2026, the Company and Thermon issued a joint press release (the “ Press Release”) announcing the execution of the Merger Agreement and the entry into the foregoing transactions. A copy of the Press Release is attached hereto as Exhibit 99.1 and incorporated into this Item 7.01 by reference. In addition, the Company provided supplemental information regarding the proposed Transactions in connection with presentations to analysts and investors. A copy of the investor presentation is attached hereto as Exhibit 99.2. In accordance with General Instruction B.2 of Form 8-K, the information under this Item 7.01 shall not be deemed “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934, nor shall it be deemed incorporated by reference in any filing. No Offer or Solicitation This communication is for informational purposes only and is not intended to and shall not constitute an offer to buy or sell or the solicitation of an offer to buy or sell any securities, or a solicitation of any vote or approval, nor shall there be any sale of securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. No offering of securities shall be made, except by means of a prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended. Additional Information and Where to Find It This communication is being made in respect of the proposed Transactions involving the Company and Thermon, among other things. The issuance of shares of Company Common Stock in connection with the Transactions will be submitted to the Company Stockholders for their consideration, and the proposed merger transaction will be submitted to the stockholders of Thermon for their consideration. In connection therewith, the Company intends to file with the SEC a registration statement on Form S-4 (the “ Registration Statement”) that will include a joint proxy statement/prospectus. Each of the Company and Thermon may also file other relevant documents with the SEC regarding the proposed transaction. This communication is not a substitute for the joint proxy statement/prospectus or registration statement or any other document that the Company or Thermon, as applicable, may file with the SEC in connection with the proposed transaction. After the Registration Statement has been declared effective by the SEC, a definitive joint proxy statement/prospectus will be mailed to the stockholders of the Company and Thermon. BEFORE MAKING ANY VOTING OR INVESTMENT DECISION, INVESTORS AND SECURITY HOLDERS OF THE COMPANY AND THERMON ARE URGED TO READ THE REGISTRATION STATEMENT, JOINT PROXY STATEMENT/PROSPECTUS AND ANY OTHER RELEVANT DOCUMENTS THAT MAY BE FILED WITH THE SEC, AS WELL AS ANY AMENDMENTS OR SUPPLEMENTS TO THESE DOCUMENTS, CAREFULLY AND IN THEIR ENTIRETY IF AND WHEN THEY BECOME AVAILABLE BECAUSE THEY CONTAIN OR WILL CONTAIN IMPORTANT INFORMATION ABOUT THE COMPANY, Thermon, THE PROPOSED TRANSACTION AND RELATED MATTERS. Investors and security holders will be able to obtain free copies of the registration statement and joint proxy statement/prospectus, as well as other filings containing important information about the Company, Thermon and the proposed transaction, once such documents are filed with the SEC through the website maintained by the SEC at https://www. sec. gov. Copies of the documents filed with the SEC by the Company will be available free of charge on the Company’s website at https://investors. cecoenviro. com/. Copies of the documents filed with the SEC by Thermon will be available free of charge on Thermon’s website at https://ir. thermon. com. The information included on, or accessible through, the Company’s or Thermon’s website is not incorporated by reference into this communication. Participants in the Solicitation The Company, Thermon and certain of their respective directors and executive officers may be deemed to be participants in the solicitation of proxies in respect of the proposed transaction. Information about the directors and executive officers of the Company, including a description of their direct or indirect interests, by security holdings or otherwise, is set forth in (i) the Company’s proxy statement for its 2025 Annual Meeting of Stockholders, which was filed with the SEC on April 10, 2025 (and which is available athttps://www. sec. gov/ix? doc=/Archives/edgar/data/3197/000155837025004649/ceco-20250520xdef14a. htm), (ii) a Form 8-K filed by the Company on July 24, 2025 (and which is available athttps://www. sec. gov/ix? doc=/Archives/edgar/data/0000003197/000095017025098303/ceco-20250718. htm), (iii) a Form 8-K filed by the Company on September 16, 2025 (and which is available athttps://www. sec. gov/ix? doc=/Archives/edgar/data/0000003197/000119312525204657/ceco-20250912. htm) and (iv) to the extent holdings of the Company’s securities by the directors or executive officers of the Company have changed since the amounts set forth in the Company’s proxy statement for its 2025 Annual Meeting of Stockholders, such changes have been or will be reflected on Initial Statement of Beneficial Ownership of Securities on Form 3, Statement of Changes in Beneficial Ownership on Form 4, or Annual Statement of Changes in Beneficial Ownership on Form 5 filed with the SEC, which are available at https://www. sec. gov/cgi-bin/own-disp? action=getissuer& CIK=0000003197. Information about the directors and executive officers of Thermon, including a description of their direct or indirect interests, by security holdings or otherwise, is set forth in (i) Thermon’s proxy statement for its 2025 Annual Meeting of Stockholders, which was filed with the SEC on June 18, 2025 (and which is available athttps://www. sec. gov/Archives/edgar/data/1489096/000148909625000097/thr-20250618. htm), (ii) a Form 8-K filed by Thermon on July 1, 2025 (as amended July 15, 2025) (and which is available athttps://www. sec. gov/ix? doc=/Archives/edgar/data/0001489096/000148909625000115/thr-20250701. htm) and (iii) to the extent holdings of Thermon’s securities by the directors or executive officers of Thermon’s have changed since the amounts set forth in Thermon’s proxy statement for its 2025 Annual Meeting of Stockholders, such changes have been or will be reflected on Initial Statement of Beneficial Ownership of Securities on Form 3, Statement of Changes in Beneficial Ownership on Form 4, or Annual Statement of Changes in Beneficial Ownership on Form 5 filed with the SEC, which are available at https://www. sec. gov/cgi-bin/own-disp? action=getissuer& CIK=0001489096. Other information regarding the participants in the proxy solicitations and a description of their direct and indirect interests, by security holdings or otherwise, will be contained in the joint proxy statement/prospectus and other relevant materials to be filed with the SEC regarding the proposed transaction when such materials become available. Investors should read the joint proxy statement/prospectus carefully when it becomes available before making any voting or investment decisions. You may obtain free copies of these documents from the Company and Thermon using the sources indicated above. Forward Looking Statements This Current Report on Form 8-K contains “forward-looking statements” within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act. All statements, other than statements of historical fact, included in this Form 8-K that address events, or developments that the Company and Thermon expect, believe, or anticipate will or may occur in the future are forward-looking statements. The words “intend,” “expect,” and similar expressions are intended to identify forward-looking statements. Forward-looking statements in this Current Report on Form 8-K include, but are not limited to, statements regarding the Transactions, pro forma descriptions of the combined company and its operations, integration and transition plans, synergies, opportunities and anticipated future performance. However, the absence of these words or similar expressions does not mean that a statement is not forward-looking. There are a number of risks and uncertainties that could cause actual results to differ materially from the forward-looking statements included in this Current Report on Form 8-K. These include the expected timing and likelihood of completion of the Transaction, including the timing, receipt and terms and conditions of any required governmental and regulatory approvals of the Transaction that could reduce anticipated benefits or cause the parties to abandon the Transaction, the ability to successfully integrate the businesses, the occurrence of any event, change or other circumstances that could give rise to the termination of the Merger Agreement, the possibility that stockholders of the Company or Thermon may not approve the Transaction, the risk that the parties may not be able to satisfy the conditions to the Transaction in a timely manner or at all, risks related to disruption of management time from ongoing business operations due to the Transaction, the risk that any announcements relating to the Transactions could have adverse effects on the market price of the Company’s common stock or Thermon’s common stock, the risk that the Transactions and its announcement could have an adverse effect on the ability of the Company and Thermon to retain customers and retain and hire key personnel and maintain relationships with their suppliers and customers and on their operating results and businesses generally, the risk the pending Transactions could distract management of both entities and they will incur substantial costs, the risk that problems may arise in successfully integrating the businesses of the companies, which may result in the combined company not operating as effectively and efficiently as expected, the risk that the combined company may be unable to achieve synergies or it may take longer than expected to achieve those synergies and other important factors that could cause actual results to differ materially from those projected. All such factors are difficult to predict and are beyond the Company’s or Thermon’s control, including those detailed in the Company’s annual reports on Form 10-K, quarterly reports on Form 10-Q and current reports on Form 8-K that are available on its website at https://investors. cecoenviro. com and on the SEC’s website at https://www. sec. gov, and those detailed in Thermon’s annual reports on Form 10-K, quarterly reports on Form 10-Q and current reports on Form 8-K that are available on Thermon’s website at https://ir. thermon. com and on the SEC’s website at https://www. sec. gov. All forward-looking statements are based on assumptions that the Company or Thermon believe to be reasonable but that may not prove to be accurate. Such forward-looking statements are based on assumptions and analyses made by the Company and Thermon in light of their perceptions of current conditions, expected future developments, and other factors that the Company and Thermon believe are appropriate under the circumstances. These statements are subject to a number of known and unknown risks and uncertainties. Forward-looking statements are not guarantees of future performance and actual events may be materially different from those expressed or implied in the forward-looking statements. The forward-looking statements in this Current Report on Form 8-K speak as of the date of this Current Report on Form 8-K. Neither the Company nor Thermon undertakes, and each of them expressly disclaims, any duty to update any forward-looking statement whether as a result of new information, future events or otherwise, except as required by law. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof.

Item 9.01 Financial Statements and Exhibits. (d) Exhibits: Exhibit Description No. 2.1 Agreement and Plan of Merger, dated as of February 23, 2026, by and among the Company, Merger Sub Inc., Merger Sub LLC and Thermon. ──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── 10.1 Form of Voting Agreement. 99.1 Joint Press Release, dated as of February 24, 2026, announcing the execution of the Merger Agreement. 99.2 Investor Presentation, dated as of February 24, 2026. 104 Cover Page Interactive Data File (formatted as Inline XBRL). SIGNATURE