Viessmann Vitodens 200-W F8 148 — Gas Valve Closes Too Late
F8 148
Gas valve closes too late. The gas valve closes too late, so the burner is in fault mode; check the gas valve, check both control wiring and connections, and press reset button R. The table classifies it as Locking (manual reset).
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 Vitotronic control (B2HA) on Vitodens 200-W B2HA models (B2HA-285, B2HA-311, B2HA-352, B2HA-399, B2HA-530), as documented in Vitodens 200-W B2HA Service Instructions, sizes 112–150/399/530, doc 5683 710 - 37 (10/2025) — same fault families documented for sizes 19–35 (5683 702 - 17) and 80–100/285–352 (5685 828 - 23) (5683 710 - 37). Codes can differ between controller generations, so always check the manual that matches your unit.
- Viessmann Vitodens 200-W (B2HA, 285–530 MBH)
- Viessmann Vitodens 200-W B2HA-285
- Viessmann Vitodens 200-W B2HA-311
- Viessmann Vitodens 200-W B2HA-352
- Viessmann Vitodens 200-W B2HA-399
- Viessmann Vitodens 200-W B2HA-530
Controller: Vitotronic control (B2HA). Source manual: 5683 710 - 37 (2025-10).
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 →Burner assembly
The burner assembly is where gas and air meet and burn inside a boiler, and its condition decides whether combustion is clean or makes carbon…
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 Viessmann Vitodens 200-W (B2HA, 285–530 MBH).
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
- Vitodens 200-W B2HA Service Instructions, sizes 112–150/399/530, doc 5683 710 - 37 (10/2025) — same fault families documented for sizes 19–35 (5683 702 - 17) and 80–100/285–352 (5685 828 - 23) · 5683 710 - 37 · accessed September 7, 2026
Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.