About error code E168

If you are a homeowner looking for advice on error code E168 please consult our homeowner information.

Error code E168 could be telling you that a number of things are wrong with the boiler in question. Typically, this error code is reporting on one of four problem areas. The first two problems listed below are the most common.

1) The boiler has been reporting other codes previously

In this case, other error codes have appeared on your boiler before code E168. The boiler will have detected a fault and displayed the relevant error code. The boiler will then have been reset, either automatically or by a user. Once the boiler starts up again it may not be able to detect the original fault as it did before so will display E168 as a replacement for the previous code, telling the user there is an undiagnosed fault.

The codes that can display prior to E168 are:

  • E20 - Boiler temperature sensor fault
  • E28 - Flue gas temperature sensor fault
  • E50 - Domestic Hot Water temperature sensor fault
  • E110 - Overheat (O/H) Thermostat operated - check to circulation and connections to O/H T/stat
  • E119 - Water pressure switch cut out (low water pressure in boiler and system)
  • E125 - Boiler max temperature exceeded - possible circulation fault
  • E130 - Flue gas max temperature exceeded - check connections and flue NTC
  • E131 - Power has been turned off during E125 or E130 faults. Check cause of E125 and E130
  • E133 - Flame not established in time - checks to be made of gas supply, flue system, condensate discharge, spark generator, electrodes, leads and wiring harness connections
  • E156 - Under voltage (lower than 195V) has been supplied to boiler
  • E160 - Fan system fault

If this is the case, fixing the fault referenced by one of these error codes will rectify the issue.

2) The mains supply to the boiler has been interrupted or is irregular

In this case, E168 means that the boiler has been experiencing a voltage either above or below the tolerance (+/- 10%) of the required 230V supply. This can be difficult to identify as irregularities may only occur at certain times. You can either test the mains supply yourself or call in a qualified electrician. If there is a fault, consult the electrical supplier for further advice on the issue.

3) A number of boiler components may not be operational or lack electrical integrity

If neither of the above solutions work, it's recommended that the following components be tested to make sure there are no faults or any signs that they have been affected by water spillage or internal leaks:

  • Gas Valve  
  • Spark Igniter
  • Electrodes (gap & connections)
  • Pump
  • Fan
  • Wiring harness connections
  • Diverter Valve (cartridge sticking or motor issue)

Any of these parts could cause E168 to appear and aren't necessarily reported by an error code. If you find a fault, simply replace the part.

4) The PCB has developed an issue

Once every other problem has been checked, the most likely conclusion is that the PCB is faulty and needs to be replaced. Replace the whole unit and test.

If you need any advice or assistance with this issue or any other, consult Baxi Customer Support who will be happy to help diagnose the issue and find a solution as quickly as possible. Either visit the Baxi Customer Support website or get in touch on 0344 335 2266.

If you need any product literature, please visit the product page on the Main website.

Main Heating is a part of Baxi UK

Main Heating is a part of Baxi UK

Baxi UK have been manufacturing boilers since 1866, and provide support for your Main Heating boilers.

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Opening hours

Baxi Customer Support is open 363 days a year.  Mon-Fri 8am-6pm, Sat and Sun 8.30am-2pm.  Call 0344 871 1545.