PROMISSORY NOTE

EXHIBIT 10.1

PAYMENT OF THIS PROMISSORY NOTE IS SUBJECT TO THE TERMS AND CONDITIONS OF A SUBORDINATION AGREEMENT DATED ON OR ABOUT THE DATE HEREOF BETWEEN THE LENDER AND BANK OF AMERICA, N.A., AS AGENT. A COPY OF SAID SUBORDINATION AGREEMENT MAY BE OBTAINED, UPON WRITTEN REQUEST OF THE HOLDER OF THIS NOTE FROM BANK OF AMERICA, N.A., 100 FEDERAL STREET, MAIL CODE: MA5-100-08-05, BOSTON, MA 02110.

PROMISSORY NOTE

FOR VALUE RECEIVED, MESTEK, INC ., a Pennsylvania corporation, having a place of business at 260 North Elm St., Westfield, MA, 01085 (hereinafter "Borrower"), does hereby promise to pay to the order of OMEGA FLEX, INC ., a Pennsylvania corporation (hereinafter "Lender"), at its offices in Exton, Pennsylvania, or such other place as the holder hereof may designate, on or before October 20, 2010 (“Maturity Date”), the principal sum of Three Million Two Hundred Forty Nine Thousand Six Hundred Fifteen and 00/100 Dollars ($3,249,615.00), and to pay interest on the unpaid principal balance hereof at six percent (6%) per annum. Interest shall commence on the date of this Note and shall be payable monthly in arrears on the first day of each month, commencing on the first day of the month immediately following the date of this Note, and continuing until all principal amounts due hereunder are paid in full. The Borrower shall have the right to prepay the principal amount of this Note in whole or in part at any time without penalty prior to the Maturity Date. Any partial prepayment shall not relieve the Borrower of the obligation to repay the entire principal amount hereunder as such amount falls due. All interest under this Note shall be computed on the basis of the actual number of days elapsed over an assumed year consisting of three hundred sixty (360) days. All payments hereunder shall be made in lawful money of the United States in immediately available funds.

Borrower, as maker, endorser, surety, guarantor, or in any other capacity, hereby: (i) waives diligence, presentment, demand, protest and notice of presentment, notice of protest and notice of dishonor of the debt evidenced by this Note and each and every other notice of every kind with respect to this Note; and (ii) agrees that the Lender or any other holder of this Note, at any time or times, without notice to or the consent of Borrower, may grant extensions of time without limit as to the number or the aggregate period of such extensions, for the payment of any principal and/or interest due hereunder and consents to any substitution, exchange or release of collateral, and to the addition or release of any other person who may at any time be or become primarily or secondarily liable for the repayment of the indebtedness evidenced by this Note.

It shall be an event of default hereunder ("Event of Default") if: (a) Borrower shall fail to make any payment of principal or interest hereunder when due, and not cured within ten days of the date on which payment becomes due provided that there shall be no such cure period