333 error code
333 — Sensor input BX4 no function
What does Hamworthy Purewell VariHeat mk2 condensing boiler 333 mean?
Hamworthy’s official fault-code system identifies code 333 on the Purewell VariHeat mk2 as “Sensor input BX4 no function”. The code belongs to the Siemens LMS control platform used on this exact commercial boiler range.
The code identifies the condition detected by the product; it does not always identify the failed component on its own. Confirm the full code and exact model before ordering parts or attempting a reset.
The Hamworthy Purewell VariHeat mk2 condensing boiler 333 error code indicates hamworthy’s official fault-code system identifies code 333 on the Purewell VariHeat mk2 as “Sensor input BX4 no function”. The code belongs to the Siemens LMS control platform used on this exact commercial boiler range. This guide explains what the code means, the symptoms and likely causes, the checks that are safe to make, and when to stop and arrange an authorised repair.
Symptoms you may notice
The Purewell VariHeat mk2 displays code 333. Depending on the operating state, the boiler may continue with restricted functionality, prevent a burner start or enter a safety shutdown until the condition is corrected.
Common causes
The manufacturer’s listed potential cause is: Sensor input BX4 no function. The precise component or circuit must be confirmed against the boiler configuration and operating history before any part is replaced.
Before you start troubleshooting
Use the display, rating label or product menu to confirm the exact model. Similar-looking codes can have different meanings across product generations and regions.
- Record the complete code before switching the equipment off.
- Check only user-accessible controls, filters and external connections described in the manual.
- Do not open gas, refrigerant, combustion or electrical compartments.
Troubleshooting steps
Record code 333, the boiler module affected and the conditions present when it appeared. Hamworthy’s listed action is: Sensor not Parameterised. These checks should be completed by a competent commercial-heating engineer using the applicable product manual and test equipment.
Can you fix this error code yourself?
This fault is not intended for user repair. Do not remove covers or test internal components; record the code and contact an authorised technician.
A successful reset is not proof that the underlying issue is fixed. If 333 reappears, note when it happens and give that information to the service engineer.
Reset instructions
Do not reset merely to clear the display. Correct the cause first and use only the reset procedure permitted by the Purewell VariHeat mk2 operating instructions. If the code returns, stop and contact Hamworthy technical support.
Applicable products and models
Purewell VariHeat mk2 condensing boilerPurewell VariHeat mk2Current and supportedWhen to contact a professional
Contact a qualified Hamworthy commercial-heating engineer if code 333 returns, prevents operation, involves a safety circuit, or requires internal testing. Hamworthy technical support can confirm product-specific procedures.
Frequently asked questions
What does Hamworthy Purewell VariHeat mk2 condensing boiler 333 mean?
Hamworthy’s official fault-code system identifies code 333 on the Purewell VariHeat mk2 as “Sensor input BX4 no function”. The code belongs to the Siemens LMS control platform used on this exact commercial boiler range.
Can I fix Hamworthy Purewell VariHeat mk2 condensing boiler 333 myself?
This code is not classed as user-fixable. Record it and arrange authorised diagnosis rather than opening the product.
Should I reset the product after code 333?
Do not reset merely to clear the display. Correct the cause first and use only the reset procedure permitted by the Purewell VariHeat mk2 operating instructions. If the code returns, stop and contact Hamworthy technical support.
When should I arrange a repair?
Contact a qualified Hamworthy commercial-heating engineer if code 333 returns, prevents operation, involves a safety circuit, or requires internal testing. Hamworthy technical support can confirm product-specific procedures.