Weil-Mclain Boilers: Ultra Re: Status & Fault Codes The Ultra Series 1 & Series 2 boilers have a 4-digit display for monitoring operating status & fault codes. OPERATING STATUS After the display shows "Stby" for a brief period, the first character shows boiler status,...

Make: Weil-Mclain Model or Series: Ultra 310 Type: Boiler Problem Description: Low heat; Burners won't stay lit. Observed Symptoms: Low water temperature. Burners ignite normally. Burner runs for several second, makes a vibrating noise then shuts off and shows code 6. Burner retries...