Worcester Bosch CE 207 Fault Code: Causes, Fixes & Repair Costs
What does the Worcester Bosch CE 207 fault code mean?
The CE 207 fault code on Worcester Bosch boilers is one of those codes where the underlying cause depends heavily on the specific model displaying it. There are three distinct interpretations seen across the range. First, and most commonly cited, it points to a communication breakdown between the main PCB (printed circuit board) and the boiler's control panel or user interface — sometimes described as a Heat Control Module fault. Second, on certain models the CE prefix indicates low system water pressure, meaning the boiler has detected pressure below the safe minimum (typically under 0.7 bar). Third, on some variants it flags a temperature sensor fault, where one of the flow or return sensors is reading incorrectly. Because all three interpretations carry the same code on different models, checking your specific boiler's manual is essential before proceeding.
General guidance only — not a substitute for professional advice, and not certified by a Gas Safe engineer. Always have your specific appliance assessed by a qualified professional. 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
- Low system water pressure Common
On models where CE signals a pressure fault, the boiler has detected water pressure below its safe operating threshold. This typically happens after radiators have been bled, following a slow drip from a fitting or radiator valve, or because of a weeping pressure relief valve. The pressure gauge will usually confirm this — anything under 1.0 bar at rest is too low. This is the easiest cause to rule out yourself before calling anyone.
- Loose or damaged wiring between PCB and control panel Common
Vibration during normal boiler operation gradually works terminal connections loose over months and years. A broken, corroded, or simply unseated cable between the main circuit board and the user interface is enough to interrupt the digital communication signal and trigger CE 207. This is an internal inspection job for a Gas Safe or qualified heating engineer.
- Faulty main PCB Sometimes
The PCB acts as the boiler's central processor. If the board itself has developed a fault — through age, a power surge, moisture ingress, or a component failure — it may no longer be able to maintain communication with other modules, resulting in this error. PCB faults tend to appear on older appliances or following electrical events in the home.
- Faulty temperature sensor Sometimes
Where CE 207 represents a sensor fault, one of the primary flow or return temperature sensors is likely reading outside expected parameters. This can be caused by a damaged cable, a short circuit within the sensor itself, moisture reaching the sensor body, or the sensor having shifted from its correct mounting position.
- Faulty control panel or user interface Rare
If the user interface board itself has developed an internal fault, it may fail to exchange data correctly with the main PCB, producing the same CE 207 communication error from the other direction. This is less common than a PCB or wiring issue but is seen on older units where the control panel has accumulated wear.
How to fix it
- Check your boiler's pressure gauge DIY safe
Look at the pressure gauge on the front of the boiler. For most Worcester Bosch models the needle should sit between 1.0 and 1.5 bar when the heating is cold. If it reads below 1.0 bar, low pressure is likely the cause and you can address this yourself before calling an engineer.
- Repressurise the system via the filling loop if pressure is low DIY safe
Turn the boiler off and allow it to cool. Locate the filling loop — this is usually a short silver braided hose with one or two valves underneath or beside the boiler, or an internal filling key depending on your model. Open the valve(s) slowly and watch the gauge climb. Stop when the needle reaches 1.0–1.5 bar, then close the valve(s) fully. Turn the boiler back on. If you are unsure which component is the filling loop, refer to your boiler's user guide or call an engineer rather than guessing.
- Reset the boiler DIY safe
Press and hold the reset button (on most Greenstar models this is a dedicated button marked with a flame and cross symbol) for approximately 3 seconds until the boiler attempts to restart. If CE 207 clears and the boiler fires up normally, monitor it over the next few days. If the code returns promptly — or if you need to reset more than two or three times — stop resetting and move to the next step, as repeated resets without resolution can mask a worsening problem.
- Check that your gas supply is functioning DIY safe
Confirm that other gas appliances in your home (cooker, gas hob) are working normally. If there is no gas elsewhere, contact your gas supplier rather than your boiler engineer. If gas is available elsewhere but CE 207 persists after a reset, the fault is internal to the boiler.
- Do not attempt to open the boiler casing or inspect internal wiring yourself Gas Safe engineer
Inspecting or reseating wiring connections between the PCB and control panel requires opening the boiler casing. This must only be carried out by a Gas Safe registered engineer. Beyond the safety risk, working inside the boiler without the correct qualifications will invalidate your warranty and your home insurance cover for boiler-related damage.
- Call a Gas Safe registered engineer to diagnose and repair the fault Gas Safe engineer
If CE 207 persists after checking pressure and performing a reset, a Gas Safe registered engineer needs to attend. They will use diagnostic equipment to determine whether the fault lies with the wiring loom, the main PCB, a temperature sensor, or the control panel interface, and carry out the necessary repair or component replacement safely. Ask for a written quote before any work begins.
Parts you may need
- Main PCB (model-specific) · from £220
- Flow or return temperature sensor (NTC sensor) · from £25
- User interface / control panel board · from £95
- Wiring loom / harness · from £45
- Filling loop assembly (if weeping) · from £20
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 £100–£380, depending on the underlying cause.
Frequently asked questions
CE 207 appeared after I bled my radiators — is that connected?
Very likely yes, if your model uses CE to flag low pressure. Bleeding radiators releases trapped air and also lets a small amount of water out, which drops the system pressure. Check your pressure gauge — if it reads below 1.0 bar, repressurising the system via the filling loop and then resetting the boiler should clear the fault. If pressure was already fine before you bled the radiators, or if the code returns within a day or two of repressurising, the cause is probably something else and an engineer visit is needed.
How much does it cost to fix CE 207 on a Worcester Bosch boiler in the UK?
The cost depends entirely on the root cause. If it's simply low pressure you can repressurise yourself at no cost. A Gas Safe engineer's call-out and diagnostic fee typically runs to £80–£120. A temperature sensor replacement including labour usually comes to around £100–£180. A wiring repair falls in a similar bracket. A control panel board replacement tends to cost £150–£300 including parts and labour. Main PCB replacement is the most expensive outcome — expect £300–£550 for parts and labour combined, with costs at the top of that range in London and the South East. Most people with CE 207 pay somewhere between £100 and £380 once the underlying fault is identified.
Can CE 207 mean different things on different Worcester Bosch boilers?
Yes, and this is genuinely important. Worcester Bosch uses CE as a prefix across multiple fault scenarios depending on the boiler range and software version. On some models CE 207 is a PCB or communication fault; on others it flags low water pressure; and on certain variants it indicates a temperature sensor problem. The number 207 narrows it down within your model's fault table, but without knowing your exact model you cannot be certain which applies. Check the fault code section in your boiler's user guide, or have an engineer read the full diagnostic data, before assuming a particular cause.
If CE 207 is a PCB fault, is it worth repairing or should I replace the boiler?
If your Worcester Bosch boiler is under 8–10 years old and has been serviced annually, a PCB repair or replacement at £300–£550 is usually worth doing — it gives the boiler a new lease of life and is far cheaper than a full replacement. If the boiler is over 12 years old, has a history of repeated faults, or the PCB quote comes in above £500, it's worth getting a new boiler quote at the same time so you can compare. A new Worcester Bosch Greenstar boiler typically starts around £1,800–£2,500 fully installed, but the long-term reliability and warranty (up to 12 years with annual servicing) often make it the better financial decision on an ageing appliance.