Honeywell TMO720-4 mod.35 08001 centralina di controllo

This Honeywell TMO720-4 mod.35 08001 control box is a burner control (flame safeguard) unit. Parts of this type govern the entire ignition and safety sequence of a gas or oil burner: they initiate pre-purge, start the ignition transformer, open the fuel valve, monitor the flame signal, and lock out the burner if the flame is not established within the programmed safety time. The control also reads inputs from the air pressure switch and, depending on the design, from temperature or modulation controllers. In a typical system, the control box sits between the thermostat/controller, the fan, the ignition transformer, the gas valve or oil solenoid, and the flame detector (ionisation electrode or UV/IR scanner). It drives these components in the correct order and enforces the required safety times. For selection, the key parameters are the exact series and type designation, supply voltage, the duration of safety time and pre-purge time, and the flame detection method. Even within the same brand, a control box of one series is normally not interchangeable with another series; a mismatched safety time is a safety hazard, not a functional nuisance. Always verify the electrical connection pattern (base or plug) and that the control matches the burner’s existing wiring. When replacing a control box of this class, confirm the original part number and any modifications (indicated by a suffix like “mod.35”). Do not assume that a control box with a similar appearance or the same housing is a direct replacement. The TMO720 designation and the specific manufacturer codes (08001, 852.124.128) identify this exact variant. For any further detail, consult the burner’s technical documentation or the control box datasheet.