Congratulationns 2020 GRADUATES SELID Mechanical Contractor serving the Williston area for over 65 years. Your local Lennox dealer for all your heating & air conditioning needs! 2219 2ND AVE W. 572-5887 PLUMBING & HEATING INC. Congratulationns 2020 GRADUATES SELID Mechanical Contractor serving the Williston area for over 65 years. Your local Lennox dealer for all your heating & air conditioning needs! 2219 2ND AVE W. 572-5887 PLUMBING & HEATING INC.