Upon arrival unit was on but not running. Turned the temp up on the thermostat and the burner started up but did not finish starting up. Hooked up to the Beckett primary control and found the primary control was losing power from the aquastat intermittently causing the burner to not go through a full run cycle. Also found the aquastat display was malfunctioning. The display was constantly changing numbers when it should only change when the unit temp changes. After getting customer authorization we replaced the aquastat with a new one. Started the unit up and it turned on correctly. Ran hot water and turned the heat on to verify proper operation. Unit is working properly.