Bosch Thermotechnology · Error codes
Bosch/Buderus SSB255-512 27 — Flame Out Too Late Error
27
Flame Out Too Late Error. Flame still present 10 sec. after closing the gas valve Remedy: Replace the gas valve The table classifies it as lockout.
If you smell gas
- Stop what you are doing. Do not use phones, switches, matches or anything that can spark inside.
- Go outside and leave the door open behind you.
- Call the FortisBC 24-hour emergency line at 1-800-663-9911 or dial 911.
Only after that, call ROMA about the boiler. Official guidance: FortisBC gas leaks and odour.
Applies to
This gas-train fault code is displayed by the SSB control on SSB255, SSB399 and SSB512 models, as documented in SSB255/399/512 Installation Instructions, doc 6720818454 (05.2019), sections 6.1.1–6.1.2 (6720818454). Codes can differ between controller generations, so always check the manual that matches your unit.
- Bosch Thermotechnology Buderus SSB (85-512, discontinued)
- Buderus SSB85
- Buderus SSB120
- Buderus SSB160
- Buderus SSB255
- Buderus SSB399
- Buderus SSB512
Controller: SSB control. Source manual: 6720818454.
Why a code is not a diagnosis
A gas-train code involves the gas valve or its electrical circuit. It does not mean there is a leak; the circuit, coils and wiring must be measured by a licensed technician.
Safe things to observe
- If you smell gas, stop, go outside and call your gas utility's emergency line or 911 before anything else.
- Note the exact code and what the appliance was doing when it appeared.
- Check whether other gas appliances in the building are working.
Do not
- Do not reset or run the appliance while the gas valve circuit is suspect.
- Do not touch the gas valve.
How professional service helps
- A technician verifies harness connections and coil resistances against the manual before replacing parts.
- 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.
Gas valve
The gas valve is the boiler's controlled gateway for gas: it opens only when the control has proven safe conditions, meters the fuel to the burner,…
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…
- Emergency Boiler Repair
Priority gas boiler repair for homes and buildings in Greater Vancouver with no heat, no hot water, a locked-out boiler or a leak.
Every boiler part explained — what it does, how it fails and what a technician checks.
Documented for Bosch Thermotechnology Buderus SSB (85-512, discontinued).
Frequently asked questions
Does this code mean I have a gas leak?
Not by itself. If you smell gas, stop, leave the building and call your gas utility's emergency line or 911 from outside before anything else. Otherwise the code points to a fault a technician confirms on site.
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
- SSB255/399/512 Installation Instructions, doc 6720818454 (05.2019), sections 6.1.1–6.1.2 · 6720818454 · accessed September 7, 2026
Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.