PID or digital display shows an over-temperature or over-pressure error, boiler pressure climbs rapidly, safety valve may vent steam.

Safety first: Turn the machine OFF immediately and unplug it. Allow the boiler to cool fully. Do not open any fittings while the boiler is hot or under pressure.

• Observe pressure gauge: If the boiler pressure exceeds normal operating range (around 1.0–1.4 bar for many Rocket models), the pressure control system is not regulating correctly.
• Inspect pressurestat or PID sensor: On non-PID models, locate the pressurestat on top or side of the boiler. Check for loose wires or signs of moisture damage. On PID models, inspect the temperature probe wiring.
• Check vacuum breaker: A stuck vacuum breaker can cause unusual pressure behavior. With the machine cool, inspect the vacuum breaker valve on top of the boiler for scale buildup. Clean or replace if it is heavily scaled or stuck.
• Do not bypass safety devices: Never bridge or bypass the pressurestat, thermostat, or safety valve. If these components are suspected faulty, they must be replaced with correct Rocket-spec parts.
• Persistent overheat errors: If the machine repeatedly overheats or vents from the safety valve, stop using it and arrange service. Overpressure can be dangerous.