Worcester Boiler Error Code HH: Meaning, Symptoms, Actions, Costs, Causes, Prevention
Worcester Boiler Error Code HH indicates that your boiler is in commissioning mode, running a setup programme to ensure proper functionality. During this time, you may notice missing digits on the display and temporary inaccessibility of heating modes, though hot water may still be available. When you see this code, it’s best to wait for the commissioning cycle to complete, which typically takes about 20 to 30 minutes. There are no associated repair costs, as this is a standard procedure for new installations or after power interruptions. The primary cause is the initial startup of a new boiler or prolonged power disruptions causing the system to re-enter commissioning mode. Preventative measures include ensuring a stable power supply to avoid unintentional resets. Always consult a Gas Safe engineer if you have concerns or if the boiler doesn’t resume normal operation after the commissioning cycle. The next section will explain the meaning of this fault in more detail.
Meaning of the Worcester Boiler Error Code HH
Worcester Boiler Error Code HH indicates that your boiler is in commissioning mode. This mode runs an automatic setup process after installation or power restoration. During commissioning, the boiler calibrates sensors, checks internal components, and ensures correct operation. The display may show missing digits or appear incomplete while the process runs. Heating functions remain inaccessible, but hot water may still be available. This mode typically lasts 20 to 30 minutes before normal operation resumes. The HH code is not a fault but a temporary system state required for proper boiler function.
How long does the HH error code last?
The HH error code typically lasts between 20 and 30 minutes. The exact duration depends on system conditions and component checks. Once commissioning ends, the boiler switches to normal operation automatically.
Can I speed up the commissioning process?
You cannot manually speed up the HH commissioning process. The boiler follows a preset sequence to ensure all checks are completed correctly. Interrupting the process may cause errors or incomplete setup.
Does the HH code mean my boiler needs repair?
No, the HH code does not mean your boiler needs repair. It is part of the normal commissioning process. If the code persists beyond 30 minutes or the boiler does not resume operation, consult a Gas Safe engineer.
The next section will describe the symptoms of this fault in more detail.
Symptoms of the Worcester Boiler Error Code HH
Worcester Boiler Error Code HH appears when the boiler enters commissioning mode. This mode temporarily disables heating functions while the system runs diagnostic checks. The boiler display may appear incomplete, with missing digits or flickering segments. Some models may show an HH code directly, while others display a blank screen or flashing symbols. Hot water may still function, but radiators remain cold until the process completes. The boiler remains unresponsive to manual adjustments during this time. If commissioning completes successfully, the HH code disappears, and normal operation resumes.
How To Recognise The Worcester Boiler Error Code HH on Different Types of Boilers
Worcester Combi Boilers
Combi boilers typically show the HH error code on their digital display. The screen may flicker or appear partially blank during commissioning. Hot water supply remains available, but the central heating will not function until the process finishes.
Worcester System Boilers
System boilers with a digital display show the HH code or a similar commissioning message. The system pump may activate briefly, but radiators will stay cold. If the boiler is connected to a hot water cylinder, stored hot water remains usable.
Older Non-Digital Boilers
Older Worcester boilers without a digital display do not show an HH code directly. Instead, users may notice the boiler remains unresponsive after a power reset. The boiler does not ignite for heating, and indicator lights may flash or remain off.
The next section suggests actions to take in the event of the Worcester Boiler Error Code HH.
What to Do When Your Worcester Boiler Shows the HH Error Code
When your Worcester boiler displays the HH error code, it is running its commissioning process. The best course of action is to wait for the process to complete. This usually takes 20 to 30 minutes, after which the boiler should resume normal operation. Avoid pressing buttons or adjusting settings, as this can interfere with the commissioning cycle. If the code remains after 30 minutes, restart the boiler by turning it off and on using the main power switch. If the HH code still does not clear, consult your boiler manual for model-specific guidance.
Safety Disclaimer
Always follow the instructions in your Worcester boiler manual. Do not attempt to open the boiler casing or adjust internal components. Only a Gas Safe registered engineer should perform repairs or advanced diagnostics. If you notice a strong gas smell, hear unusual noises, or suspect a leak, turn off the gas supply at the meter and contact a professional immediately.
How to reset a Worcester boiler with an HH error code?
You can reset your Worcester boiler by turning it off at the power switch, waiting 30 seconds, and then turning it back on. If the HH code remains, leave the boiler for 30 minutes to complete commissioning.
Should I turn off my Worcester boiler when it shows HH?
No, you should not turn off the boiler immediately. The HH code indicates an automatic commissioning process. Interrupting this cycle may cause further delays. Only turn the boiler off if the code persists beyond 30 minutes.
Where is the power switch on a Worcester boiler?
The power switch is usually located on the front panel or side of the boiler casing. If you cannot find it, check your user manual for specific instructions.
Should I shut off the gas supply when the HH code appears?
No, you do not need to shut off the gas supply. The HH code is not related to a gas leak or safety issue. However, if you smell gas or hear hissing noises, turn off the gas at the meter and call a Gas Safe engineer.
How to check if my boiler is still working during the HH error?
Check if your hot water is running, as some models allow hot water use during commissioning. The heating will not function until the process completes. If the display remains blank after 30 minutes, a reset may be needed.
Should I call an engineer if the HH error code does not clear?
Yes, if the HH code stays on the display for more than 30 minutes after a reset, contact a Gas Safe registered engineer. There may be an underlying issue requiring professional diagnosis.
The next section will describe the costs to repair this fault.
Cost to Repair Worcester Boiler Error Code HH
The Worcester Boiler Error Code HH does not usually require repairs. This code indicates the commissioning process, which completes automatically. If the code persists beyond 30 minutes, you may need a professional inspection.
A Gas Safe engineer visit for diagnostics costs between £60 and £120. If a reset does not fix the issue, further investigation may be needed. Minor fixes, such as a software reset or minor sensor calibration, typically cost between £80 and £150.
If a faulty component causes the issue, repair costs increase. A new temperature sensor or control board can cost between £150 and £350, including parts and labour. In rare cases, a full boiler replacement costs £1,500 to £3,000, depending on the model.
The most common cost is the engineer’s call-out fee. Many cases require no part replacements, meaning the total cost remains below £150. If your boiler is under warranty, repairs may be free if a fault is confirmed.
The next section will describe the major causes of the fault in more detail.
The 2 Major Causes of the Worcester Boiler Error Code HH
The Worcester Boiler Error Code HH primarily arises due to two main causes: the boiler entering commissioning mode and prolonged power disruptions.
1. Boiler Entering Commissioning Mode
When a new Worcester Bosch boiler is installed and powered on, it initiates a commissioning mode. During this phase, the boiler runs a setup program to ensure all components function correctly. The display may show an ‘HH’ or ‘hh’ symbol, sometimes accompanied by missing digits. This is a standard procedure and not an error. The boiler will automatically complete this process, typically within 20 to 30 minutes, after which normal operation resumes.
2. Prolonged Power Disruptions
Extended power outages or significant fluctuations can cause the boiler to re-enter commissioning mode upon restoration of power. This re-initiation is a safety feature designed to recalibrate the system, ensuring optimal performance. While this is a normal response, frequent occurrences may indicate underlying electrical issues that need addressing to prevent repeated disruptions to your boiler’s operation.
Understanding these causes helps in identifying that the HH code is not a fault but a standard operational feature of Worcester Bosch boilers.
Preventing Future Worcester Boiler Error Code HH
Regular boiler maintenance helps prevent unexpected issues, including repeated commissioning cycles. An annual boiler service ensures that all components function correctly and minimises the risk of power-related resets. Keeping your boiler under a service contract provides routine checks and early detection of potential faults.
A stable power supply prevents unnecessary re-commissioning. Using a surge protector or an uninterrupted power supply (UPS) helps protect the boiler from electrical disruptions. Following the manufacturer’s user manual ensures the system runs smoothly without unnecessary resets.
Disclaimer
Only perform actions described in the Worcester boiler user manual. Do not attempt to open or repair internal components yourself. Any servicing, repairs, or diagnostic work should be carried out by a Gas Safe registered engineer to ensure safety and compliance with UK regulations.