Chris McQuistion came out due to no heat on boiler. Performed diagnostic. Found expansion tank is faulty which more than likely caused the boiler to air lock. Found that the auto feed and back flow preventer has failed. This is the reason why it did not try to fill back up. Found premium auto air vent has been leaking and corrosion around it. This is recommended to be replaced. Found circ pump has rust and corrosion around it which is signs of failure. Found 11/4†isolation valve has corrosion around it and is recommended to be replaced. Gave customer options. Customer would like a bid on replacement with a wall hung high efficiency boiler and a novo water conditioning system with water softening. Scheduling Lance to come out. Will credit trip charge and diagnostic towards either repair or replacement done.