Potterton E50 fault code explained
If your Potterton boiler shows E50, Baxi’s current fault-code reference describes it as a domestic-hot-water NTC sensor fault on a tank boiler, caused by either a short circuit or an open circuit.
In practical terms, the boiler is not receiving a valid temperature reading from the sensor associated with the stored hot-water system. It may stop or limit operation because it cannot safely control hot-water temperature using an unreliable signal.
What is a DHW NTC sensor?
DHW means domestic hot water: the water used at taps and showers. NTC is the type of temperature sensor used to report how hot the water is. On a compatible boiler-and-cylinder installation, that reading helps the controls decide when heat is needed and when the target temperature has been reached.
E50 does not prove that the sensor itself must be replaced. The manufacturer’s wording covers both an open-circuit and short-circuit condition, so the fault could relate to the sensor signal, its connection or another part of the control path. Only proper checks on the exact system can establish what needs repairing.
Which Potterton boilers can show E50?
Baxi Heating UK, which provides the current technical reference for Potterton products, includes E50 in the error-code table whose appliance group contains Potterton Assure Combi and System boilers. The E50 description specifically refers to a tank boiler, so it is most relevant where the installation uses stored hot water and a cylinder sensor.
Not every Potterton model uses the same codes. A Potterton Titanium heat-only boiler, an older Potterton range and a Potterton Assure installation can have different controls and fault displays. Check the model name and its own user guide before assuming this meaning applies.
What might you notice?
- The E50 code remains on the boiler display.
- Stored hot water does not heat as expected.
- Hot-water operation becomes unreliable or stops.
- Heating may behave differently depending on the system design.
The code is more useful than the symptom alone. Note both the model and the complete display before booking a repair.
Can I fix E50 myself?
No internal repair is suitable for a homeowner. Do not remove the boiler casing, open electrical enclosures, disconnect a cylinder sensor or test wiring. Sensor and circuit checks require the right information and equipment, and gas-appliance work must remain within the competence of a Gas Safe registered engineer.
You can safely confirm that the boiler and external controls have power, record the code and check whether the hot-water cylinder has an accessible external control that has been accidentally switched off. Do not dismantle it. If the exact user guide permits a normal reset, follow that instruction once. If E50 returns, arrange a repair rather than repeatedly resetting the boiler.
What will the engineer check?
The engineer will identify the precise Potterton model and how its hot-water cylinder is controlled. They can then assess the sensor reading, relevant connections and boiler controls using the correct service information. The result determines whether the repair involves the sensor, a connection or another control component.
This model-specific approach matters because E50 is not a universal Potterton code and the display alone cannot name a definite failed part.
Is E50 a gas emergency?
E50 is listed as a hot-water temperature-sensor circuit fault, not as confirmation of a gas leak. Keep the appliance casing closed and arrange a repair.
If you smell gas, suspect carbon monoxide, or a carbon monoxide alarm sounds, treat that separately as an emergency. Call the National Gas Emergency Service on 0800 111 999 and follow its instructions.
Get your Potterton E50 fault fixed
Book Incredaboil’s fixed-price boiler repair to get the hot-water sensor fault assessed safely and the boiler put right.