he Contractor shall perform all tasks and repairs to HVAC systems in accordance with the contract documents and shall be available on an on-call basis, prepared to perform routine and urgent maintenance, repairs, replacements, and installations at properties owned and managed by the Methuen Housing Authority. The scope of work, without limiting the generality thereof, includes furnishing all labor, materials, tools, equipment, transportation, and supervision required to accomplish the work described herein. All work must be performed in accordance with all local, state, and federal codes, including Massachusetts Building and Mechanical Codes, OSHA regulations, and all applicable industry standards and manufacturer specifications. All preventive maintenance shall be performed in accordance with the original equipment manufacturer's specifications to ensure proper functioning and maintain warranty coverage. All work under this contract must be performed by Massachusetts-licensed HVAC technicians and, where applicable, contractors certified under EPA Section 608 for refrigerant handling.