Brivis fault code h01 57
Pressure switch stuck closed, flue fan off but pressure detected.
What h01 57 actually means
The pressure switch is stuck closed. The flue fan is off, so the heater expects no pressure, and the switch says there is some. Mechanically the opposite of h01 56 and usually a failed switch rather than a flue problem.
What causes it
- Pressure switch contacts welded or stuck
- Wiring fault at the switch
- Very strong wind at the flue terminal holding the switch closed, which is rarer but real on exposed sites
- Control board misreading the input
Most likely first. That order is from what we actually find on site, not from the manual.
Safe to check yourself
No tools, no covers off, nothing to do with gas, refrigerant or wiring.
- Nothing. Turn it off at the controller and book it
What we check on site
So you know what you’re paying for.
- Switch continuity with the fan off
- Wiring and terminal inspection
- Board input verification
- Flue terminal position and exposure check
Can you keep using it?
No. A pressure switch that reads closed when it should be open means the heater cannot verify its own flue, which is the safety this switch exists to provide.
What the fix usually involves
Usually the switch, which is a stocked part and a short job.
Is it worth fixing?
That depends almost entirely on how old the unit is. Past about ten years on hot water and gas heating, and twelve on aircon, a significant repair usually costs more per remaining year than a replacement does — and it’s the same point at which the VEU rebate is worth the most, because old inefficient appliances are exactly what the scheme pays to remove. If yours is young and the fault is a component, we’ll fix it and say so.
Repair or replace? The 10-year rule, and what the rebate is worth →