Honeywell Control box 02431

The Honeywell Control box 02431, type designations MZ 770 S, IRD 1010, and UVD 970, is a control box for gas or oil burners. It operates on a supply voltage of 220–240 V and has a safety time of 10 seconds. The pre-purge and pre-ignition times are both 12 seconds, with a post-ignition time of 2–5 seconds. The net weight is 0.25 kg, and it has a protection class of IP44. It can be mounted in any position and fits the Resideo TF832.3.

Control boxes of this type are selected by matching the supply voltage, safety time, and purge/ignition timings to the burner's specifications. The mounting position is flexible, but the wiring base must be compatible with the existing harness. Before ordering, verify the flame detection method (e.g., photoresistor, infrared, or UV) and ensure the control box's protection class meets the installation environment. Physical dimensions and weight should be compared to the original part to ensure a proper fit.

When control boxes of this kind fail, the burner may fail to start, lock out after the safety time, or shut down intermittently. Common issues include faulty flame detection, which can cause repeated lockouts, or internal relay failures leading to no ignition. Check the flame sensor for contamination or damage, and verify the supply voltage and wiring connections. If the control box resets after a lockout but the problem persists, it may need replacement.