Honeywell Gas burner safety control box MMI810.1 mod.43 0622520

Honeywell MMI810.1 mod.43 is a gas burner safety control box for two-stage forced draught and combi oil/gas burners. It supports ionization probe or infrared flicker detector as flame detectors. The device operates on 220–240 V supply voltage, consumes 10 W, and has a waiting time of 9 s, air proving switch reaction time of 6.0 s, pre-purge time of 40 s, pre-ignition time of 3 s, safety time of 3 s, and time delay between terminals 6 and C of 10 s. It has an amplifier sensitivity of 1 µA and requires a minimum current of 5 µA from the flame detector. The control box weighs 0.35 kg net, has IP44 protection, and is housed in a non-flammable plastic casing.

When selecting a replacement control box of this type, ensure the supply voltage, flame detector type, and program sequence match the burner's requirements. Verify the waiting time, pre-purge time, safety time, and other timing parameters align with the burner's specifications. The control box must be compatible with the burner's wiring and mounting configuration. Check the physical dimensions and mounting holes to ensure a proper fit.

Common failures of this kind of control box include failure to start, intermittent lockouts, or no ignition. Symptoms may include the burner not responding to the thermostat, repeated resetting, or the fault indicator lighting up. Check the flame detector signal, wiring connections, and the control box's internal fuses. If the control box is faulty, it may need to be replaced.