Bosch Thermotechnology · Error codes
Buderus GB142 3F 273 — The Blower is Switched Off during the Safety Test
3F 273
The blower is switched off during the safety test. The blower is switched off during the safety test, so fully switch off the heat request and check that the blower is still operational after 1 minute. The table classifies it as Blocking boiler-fault code.
Applies to
This fault code is displayed by the BC10 control on Buderus GB142 models (24–60), as documented in Buderus GB142 Service Instructions, doc 7214 9400 (chapter 7 fault codes) (7214 9400/07). Codes can differ between controller generations, so always check the manual that matches your unit.
- Bosch Thermotechnology Buderus GB142
- Buderus GB142-24 kW
- Buderus GB142-30 kW
- Buderus GB142-45 kW
- Buderus GB142-60 kW
Controller: BC10 control. Source manual: 7214 9400/07 (2011-12).
Why a code is not a diagnosis
The code reports the condition the control detected; the underlying cause must be confirmed on site by a licensed technician using the manufacturer's procedure.
Safe things to observe
- Note the exact code, when it appears and what the appliance was doing.
- If the appliance has stopped, call a technician rather than repeatedly restarting it.
- If you smell gas, stop, go outside and call your gas utility's emergency line or 911 before anything else.
Do not
- Do not ignore a code that returns after a reset.
How professional service helps
- A licensed technician diagnoses the cause with the manufacturer's test procedure.
- Combustion and safety devices are verified with an analyser and the manufacturer's procedure after any repair.
Where ROMA provides on-site service
On-site service is currently offered in Greater Vancouver, BC, including Vancouver, Burnaby, Richmond, Surrey, Coquitlam, North Vancouver, West Vancouver, New Westminster, Port Coquitlam, Port Moody, Delta, Langley, Maple Ridge, Abbotsford, Chilliwack, White Rock, Pitt Meadows, Tsawwassen, Anmore, Lions Bay, Belcarra, Bowen Island, Mission. Everything else on this site is reference information you can use anywhere in Canada.
Parts and service
Parts commonly involved
These parts appear in the documented text for this alert. A code reports a condition, not a failed part — a technician confirms the cause by testing before anything is replaced.
Combustion fan (blower)
The combustion fan is the sealed boiler's lungs: it draws in combustion air, keeps the burner's gas-air mixture correct, and pushes flue gases out…
What a technician checks →
Service for this alert
- Gas Boiler Repair
Licensed gas technicians from ROMA Heating & Cooling diagnose and repair residential and light-commercial gas boilers across…
Every boiler part explained — what it does, how it fails and what a technician checks.
Documented for Bosch Thermotechnology Buderus GB142.
Frequently asked questions
Can I clear this code myself?
Clearing a code without fixing its cause usually just brings it back. Note the code, check the safe items on this page, then call a licensed technician. If your appliance manual describes a user reset for this exact code and it stays away, no call may be needed.
Boiler locked out? Call with the alert text ready.
The brand, model and this alert are passed along when you request service online, so the technician arrives prepared.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.
Sources and verification
- Buderus GB142 Service Instructions, doc 7214 9400 (chapter 7 fault codes) · 7214 9400/07 · accessed September 7, 2026
Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.