Common problems guide

The most common Potterton Titanium Combi problems

The faults most likely to send a Potterton Titanium Combi into lockout — with plain-English causes, what to check first, estimated repair costs and whether you need a Gas Safe engineer.

This model is discontinued. Parts can be harder to source and expensive. If repair costs are mounting, a new A-rated boiler may be the smarter choice.
20 documented codes
6 most common
2 DIY-safe checks
4 engineer needed

The 6 most common faults

01
E119 High DIY-safe

Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.

What to try first

Locate the filling loop, which is usually a silver braided hose under the boiler.Open the valves on the filling loop slowly to let mains water into the heating system.Watch the pressure gauge on the front of the boiler until the needle reaches the green zone (typically 1.0 to 1.5 bar).Close both valves tightly and remove the filling loop if it is a detachable type.

Est. cost
£80-150
Parts
Pressure gauge, Pressure sensor/transducer, Filling loop
Full guide for E119
02
Error 119 High DIY-safe

Your boiler has stopped working because the water pressure inside the heating system has dropped too low.

What to try first

Locate the external filling loop, which is usually a silver braided hose with one or two valves located underneath the boiler.Open the valve(s) slowly to allow water into the system until the pressure gauge on the front of the boiler reads between 1.0 and 1.5 bar.Close the valve(s) tightly and the boiler should automatically reset.

Est. cost
£80-120
Parts
Pressure relief valve (PRV), Pressure sensor
Full guide for Error 119
03
E20 High Engineer

Your boiler has lost the ability to accurately measure the temperature of the water circulating to your radiators, so it has safely shut down to prevent overheating.

Est. cost
£120-220
Parts
Central Heating (CH) NTC Sensor, Wiring harness
Full guide for E20
04
E28 High Engineer

Your boiler has detected an issue with the system that removes waste gases, meaning it has safely shut down to prevent any unsafe conditions.

Est. cost
£150-300
Parts
Flue NTC Sensor, Air Pressure Switch, Condensate Trap
Full guide for E28
05
E50 High Engineer

Your boiler has lost the ability to accurately measure the temperature of the hot water, so it has shut down to prevent overheating.

Est. cost
£120-200
Parts
Domestic Hot Water (DHW) NTC Sensor
Full guide for E50
06
E110 High Engineer

Your boiler has detected that it is dangerously hot and has shut itself down to prevent damage or safety issues.

Est. cost
£120-250
Parts
Safety Thermostat, Pump, Diverter Valve
Full guide for E110
Parts most often replaced

on the Potterton Titanium Combi

Pressure gaugePressure sensor/transducerFilling loopPressure relief valve (PRV)Pressure sensorCentral Heating (CH) NTC Sensor

Based on parts cited in our fault code database. Your engineer will confirm what's actually needed after diagnosis.

Call a Gas Safe engineer if…

  • You can smell gas or see signs of a leak
  • The Potterton shows an Emergency or High severity code
  • The boiler keeps locking out after repeated resets
  • You've tried the DIY checks and the fault hasn't cleared
  • There's visible water leaking from the boiler
  • The flame is yellow or orange instead of blue
See the full 20-code list for the Potterton Titanium Combi

Related guides

Boiler losing pressure → No hot water → When to replace → Symptom checker →