30 Days Free Trial - From $ · Basic - From $/month · Plus - From $/month. WHEREAS the Client wishes to engage the Contractor for repairs or service to their HVAC system as described in this Contract and the Contractor agrees to provide such services. An HVAC service contract is a written, signed document that outlines every detail of the services to be provided by an HVAC contractor, for the customer, as a part of a maintenance plan. It can also be called a service maintenance agreement, prevent