Overview
The E130 error on Potterton Promax boilers indicates that the flue overheat protection has been activated because the flue thermostat (flue temperature sensor) has tripped and the control has gone into lockout. In practice this means the boiler has detected an unsafe temperature in the flue path or has received an out-of-range / fault signal from the flue sensor, and it has shut down to protect the appliance and the property. Causes include a genuine flue overheating condition (blocked or restricted flue, poor combustion, fan failure), a faulty or incorrectly reading flue temperature sensor, wiring/connector faults between the sensor and PCB, or related component failures that affect flue temperatures or sensor readings. Severity is moderate to high. A blocked or poorly vented flue can cause unsafe combustion by-products to remain in the appliance or property, so you must not ignore repeated E130 faults. Some simple checks are safe for a homeowner, such as visually inspecting the external flue terminal and performing a controlled reset, but diagnosing and repairing anything involving the combustion chamber, gas supply, fan, internal wiring, PCB or replacing sensors should only be done by a Gas Safe registered engineer. If you suspect a flue blockage, smell of combustion gases, soot, or if the fault persists after simple checks, stop using the boiler and call a professional immediately.
Possible Cause: Flue thermostat sensor tripped (lockout)
Troubleshooting Steps
Safety first 1. If you smell gas or suspect carbon monoxide (exhaustive/sooty smells, headaches, nausea), get everyone out of the building and call the gas emergency number immediately. Do not use the boiler. 2. Before doing any inspection switch the boiler off at the mains and isolate gas if you can safely do so. Do not open sealed combustion areas or try to adjust gas components unless you are a Gas Safe registered engineer.
Initial homeowner checks (safe, do these first) 1. Note the exact model and the displayed fault code and whether any other codes are shown. 2. Check the exterior flue terminal (usually on an outside wall or roof terminal) for obvious blockages: nests, leaves, snow, heavy soot, pigeon wire displaced, or debris. Remove any obvious external blockage if it can be done safely from ground level. 3. Ensure vents and airways near the boiler are not blocked and there is adequate ventilation where the boiler is installed. 4. Power-cycle/reset the boiler: switch off at the mains, wait 2–5 minutes to allow the unit to cool, switch the mains back on and press the boiler reset button as per the manual (hold for 3–5 seconds). Some transient faults clear with a reset — if the code returns immediately, further action is required. 5. Check other basic parameters: system pressure and visible water leaks. Low pressure will not usually cause E130 but low-pressure/poor circulation can cause other faults; top up pressure only if you know how to and the boiler instructions allow it.
Further diagnostic steps (for competent homeowners with basic tools; stop and call an engineer if unsure) 1. Visual inspection inside the boiler outer cover: only do this with the mains power off. Look for loose connectors, signs of overheating (brown or blackened wiring insulation), water ingress, or corrosion at wiring plugs to the PCB and sensors. Do not touch live parts. 2. If you have a multimeter and are competent, you can check continuity of visible sensor wiring and connectors for obvious open circuits. Do not attempt to probe live gas/electrical components while the unit is powered. 3. Do not attempt to remove or replace the flue thermostat sensor itself unless you are qualified. The sensor is usually inside the flue path/heat exchanger area and requires safe isolation and reassembly to maintain appliance safety.
When to call a professional (required in most E130 cases) 1. If the E130 returns after a safe visual clear and a reset. 2. If you find any external or internal blockages you cannot safely clear, visible damage, soot inside the boiler casing, or smell combustion products. 3. If post-reset the boiler shows other related faults or will not restart.
What a Gas Safe engineer will do (for your information) 1. Confirm the fault by reading error history with the service menu. 2. Inspect and test the flue path for blockages and correct discharge, including internal flue liners where applicable. 3. Test the flue thermostat/NTC sensor resistance and behaviour over temperature and replace if out of specification. 4. Check wiring and connectors from the sensor to the PCB and repair any damaged cables. 5. Inspect and test the fan, air pressure switches and combustion to ensure proper flow and no backpressure. 6. Check combustion/gas supply and ignition components if overheating is linked to flame/combustion issues. 7. Clear the fault and perform a safe restart and post-repair checks, including CO/combustion testing if needed.
Important final notes 1. Do not keep resetting and running the boiler repeatedly if the E130 returns — that increases risk. 2. Any work involving gas components, internal sensors, PCB replacement, or dismantling sealed parts must be carried out by a Gas Safe registered engineer. 3. If in any doubt about safety or if you detect soot, staining, or smells associated with combustion, switch the boiler off and call a Gas Safe engineer without delay.
Helpful Resources
Boiler Manual
Download the official PDF manual for the Potterton Promax Combi, System, and Store.