Will not ignite. You hear the fan and the ignition attempt, but the burner never lights or lights for a moment and goes out. On a Brivis this usually traces back to the ignition system, a fouled flame sensor, a gas supply issue at the heater or a control board fault. We test rather than guess.
Lockout. After a run of failed ignition attempts, or a repeated overheat, the heater locks itself out and stops trying. Turning the controller off and back on once is reasonable; resetting it over and over is not, because the fault that caused the lockout is still there.
Fault codes. When something is wrong, a Brivis controller will often show a fault code or flash a light. The meaning differs between models and controller generations, so we do not decode them over the phone from a generic list. Send us the code, ideally with a photo of the controller screen, and the technician arrives knowing where to start.
Cuts out mid-cycle. Warm air for ten or fifteen minutes, then cold. Most often the heater is overheating because the return air filter or grille is choked, and it shuts the burner down to protect itself. Our short cycling guide explains more.