Worcester Bosch 1068 Fault Code: Causes, Fixes & Repair Costs
What does the Worcester Bosch 1068 fault code mean?
The 1068 W code appears on Worcester Bosch boilers when the external outdoor temperature sensor — an optional weather compensation accessory — stops communicating with the boiler. The 'W' designation means this is a warning or blocking-type fault rather than a full lockout, so the boiler may continue to run in a limited capacity rather than shutting down completely. Without a valid reading from the outdoor sensor, the boiler loses the ability to apply weather compensation, which can reduce efficiency by roughly 2% ErP. The root cause is almost always a problem with either the sensor itself or the cable connecting it to the boiler.
General guidance only — not a substitute for professional advice. Any gas work must be carried out by a Gas Safe registered engineer. If you smell gas or suspect carbon monoxide, leave the property and call the National Gas Emergency line on 0800 111 999.
Common causes
- Damaged or disconnected sensor cable Common
The lead running from the outdoor sensor to the boiler is exposed to outdoor conditions and can be pinched, cut by garden tools, or simply work its way loose from its terminal over time. This is the most frequent trigger for the 1068 code and the first thing worth inspecting.
- Failed outdoor sensor unit Common
The sensor itself sits outside, exposed to rain, frost, and UV light year-round. Over time the internal electronics or the sensing element can degrade, causing it to report incorrect values or drop off the circuit entirely.
- Corrosion or moisture ingress at the connection points Sometimes
Where the cable meets the sensor housing or enters the boiler casing, condensation and rainwater can creep in and corrode the terminals. This often causes an intermittent fault that comes and goes with the weather before eventually becoming permanent.
- Wiring fault inside the boiler at the sensor terminal Rare
In less common cases the cable is fine but the terminal block or wiring inside the boiler where the sensor lead is connected has become loose or corroded. This requires an engineer to investigate.
How to fix it
- Inspect the sensor cable along its full length DIY safe
Follow the thin cable from where it enters the property back out to the sensor mounted on an outside wall. Look for obvious signs of damage — cuts, crush marks, kinks, or sections that animals may have chewed. Also check both ends: make sure the plug is firmly seated at the sensor head and that the other end has not pulled free from its connection point.
- Reset the boiler once DIY safe
If the cable looks undamaged and fully connected, try a single boiler reset using the reset button or procedure described in your user manual. Occasionally a brief signal dropout can latch the warning code even after the issue has cleared. Only reset once or twice at most — repeated resets on a genuinely faulty boiler can stress the PCB.
- Visually check the outdoor sensor housing for physical damage or water ingress DIY safe
Have a close look at the plastic sensor body fixed to the outside wall. Look for cracks, missing covers, or signs that water has been getting in — staining or residue around the cable entry point are telltale signs. Do not open the boiler casing or tamper with any internal components.
- Contact a Gas Safe registered engineer to test and replace the sensor or cable Gas Safe engineer
If the visual checks do not reveal an obvious fix, or if the fault code returns after a reset, an engineer should carry a multimeter check on the sensor circuit to confirm whether the sensor, the cable, or the internal terminal connection needs replacing. Replacing the outdoor sensor is a straightforward job that does not require working on gas components, but any work inside the boiler casing should still be carried out by a competent registered engineer to protect your warranty and your safety.
Parts you may need
- Worcester Bosch outdoor weather compensation sensor kit · from £55
- Outdoor sensor replacement cable / extension lead · from £18
- Sensor terminal connector block · from £8
The exact spare depends on your boiler's GC number (on the data badge). Check this against the part before buying.
Typical repair cost
Expect to pay roughly £80–£200, depending on the underlying cause.
Frequently asked questions
Will my boiler still work with fault code 1068 showing?
In most cases, yes. Because the 1068 is a 'W' warning or blocking code rather than a hard lockout, Worcester Bosch boilers will typically continue to provide heating and hot water — they simply cannot apply weather compensation while the outdoor sensor is offline. Your boiler may run slightly less efficiently than normal, but you should not lose heat altogether. If the boiler has shut down completely, check whether a separate fault code is also displayed.
Can I fix the 1068 fault myself?
You can safely carry out some basic checks yourself: inspect the sensor cable for visible damage, make sure both ends are firmly plugged in, and try a single reset. What you should not do is open the boiler casing, disturb any internal wiring, or attempt to replace the sensor terminal connections inside the boiler — that work should be left to a Gas Safe registered engineer. The outdoor sensor itself is not a gas component, so the actual sensor swap is a relatively minor job when an engineer visits.
How much does it cost to fix a 1068 fault on a Worcester Bosch boiler?
This is one of the more affordable Worcester Bosch faults to put right. A genuine outdoor weather sensor typically costs £30–£80 for the part, and because the job does not involve major disassembly of the boiler, labour time is usually short. Most homeowners pay somewhere between £80 and £200 all in, covering the callout, an hour or so of labour, and the replacement part. Costs at the higher end of that range usually reflect more rural locations, weekend bookings, or needing both a new sensor and a cable run.
What happens if I just ignore fault code 1068 and carry on?
Because the boiler typically keeps running, some people do leave this fault unresolved for a while. The main downside is a small but real reduction in efficiency — without weather compensation the boiler cannot modulate its flow temperature based on outdoor conditions, so it may run slightly hotter than necessary on mild days. There is no immediate safety risk associated with a faulty outdoor sensor, but it is worth getting it sorted at your next service visit to keep running costs down.