Fourtech Temperature Controller Manual Free !!hot!! < FULL × 2025 >

Blinks when the controller is running an Auto-Tuning cycle. Keypad Operations

| Error Code | Description | Likely Cause & Solution | | :--- | :--- | :--- | | | Ignition failure | No gas supply, defective ignition electrode, or no flame detected. Check gas valve, reset boiler, and call a technician if persists. | | E02 | Overtemperature safety thermostat triggered | Overheating due to circulation pump failure or air in system. Check pump operation. | | E03 | Flue/Draught thermostat/pressure switch error | Flue gas recirculation, blocked flue, or fan issue. Contact technician to inspect flue and fan. | | E04 | Frequent flame loss error | Unstable flame due to gas pressure issues, incorrect burner settings, or flue problems. | | E05 | Faulty heating circuit temperature sensor | NTC sensor (measuring heating circuit water temperature) faulty or damaged. Replace sensor. | | E06 | Faulty DHW temperature sensor | NTC sensor (measuring domestic hot water) faulty or damaged. Replace sensor. | | E10 | Low system water pressure | Heating system water pressure below ~0.5 bar. Open filling loop to repressurize to 1.2-1.5 bar. | | E25/E26 | No water circulation (pump blocked) | Central heating pump seized or blocked. Call technician to check pump. | | E35 | Parasitic flame error (false flame) | Flame detected at wrong time. Check ionization electrode and main PCB. | | E96 | Undervoltage error (power supply) | Mains supply voltage dip below specified minimum. Check house electrical system. | | E98 | General ignition block | Unclear cause, often board-related. Reset boiler; if frequent, technician must investigate. | | E99 | Internal board error or gas valve relay | Internal PCB fault or gas valve relay contact issues. Often requires board replacement. | fourtech temperature controller manual free