IBC Technologies · Error codes
IBC SL G3 “Flame signal / vent block” alert
Error – Flame Signal / Vent Block
The manual lists this alert when the flame current measured by the SIM+ module drops below the minimum for the model. A weak flame signal can mean the flame is unstable, the vent is blocked, gas pressure is poor, or the flame rod is fouled, corroded or poorly grounded. The SL manual's minimum flame currents (fan at or below 3,500 RPM) are 1.4 µA for the SL 10-85 G3 and SL 14-115 G3, 1.8 µA for the SL 20-160 G3 and 3.2 µA for the SL 30-199 G3.
If a carbon-monoxide alarm sounds
- Leave the building immediately and get fresh air.
- Call 911. Do not go back inside until emergency services say it is safe.
- Have every fuel-burning appliance inspected before use.
Only after that, call ROMA about the boiler. Official guidance: Health Canada on carbon monoxide.
Applies to
This alert is shown by the V-10 touchscreen controller on SL Series G3 residential boilers (SL 10-85 G3, SL 14-115 G3, SL 20-160 G3 and SL 30-199 G3), as documented in IBC Installation & Operating Manual — SL 10-85 G3 / SL 14-115 G3 / SL 20-160 G3 / SL 30-199 G3, doc 120-276E13, sections 9.2–9.4.
Controller: V-10 touchscreen controller. Source manual: 120-276E13 (2026-08-11).
Why a code is not a diagnosis
Flame current is an electrical measurement of the flame itself; it does not say which of several causes is responsible. Vent blockage, combustion settings (CO2), gas pressure, flame-rod condition and grounding are all on the manual's check list.
Safe things to observe
- Note the alert text and whether it appears soon after ignition or later in a heating cycle.
- From a safe distance check the vent terminal and combustion-air intake for blockage.
- If a CO alarm sounds, leave the building and call 911 from outside.
- If you smell gas, leave and call FortisBC at 1-800-663-9911 or 911 first.
Do not
- Do not clean, bend or adjust the flame rod yourself.
- Do not keep resetting the boiler while the flame-signal fault is unresolved.
How professional service helps
- A technician checks the vent path, gas pressure and combustion readings (CO2) at low and high fire.
- The flame rod is cleaned or replaced, its ceramic insulator checked, and grounding verified.
- Flame current is re-measured against the manual's minimum for the specific model.
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.
Flame sensor (flame rod)
The flame sensor is the small rod that proves a gas boiler's burner is actually lit before the control will keep the gas valve open.
What a technician checks →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 →Boiler venting (flue and air intake)
A condensing boiler vents cool, wet flue gases through dedicated plastic pipe that must meet ULC S636 in Canada and the boiler manufacturer's own…
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 IBC Technologies SL Series G3.
Frequently asked questions
What is flame current?
The boiler measures a tiny electrical current that passes through the flame to prove the flame exists. When that current drops, the control suspects an unstable flame, a blocked vent or a fouled flame rod.
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
- IBC Installation & Operating Manual — SL 10-85 G3 / SL 14-115 G3 / SL 20-160 G3 / SL 30-199 G3, doc 120-276E13, sections 9.2–9.4 · 120-276E13 · accessed September 7, 2026
Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.