Slant/Fin LOW WATER LED (blinking) — Low Water Cut-off Lockout (manual Reset Mode)
LOW WATER LED (blinking)
Low water cut-off lockout (manual reset mode). When the LOW WATER light is blinking, the control has been programmed to provide low water lock-out protection and is currently locked out (manual reset LWCO mode, meets CSD-1). After the low water condition is resolved, press the TEST/SETTINGS button to reset the lock-out. Have the system checked by a qualified heating professional before resuming operation. The table classifies it as lockout.
Applies to
This low-water or pressure protection code is displayed by the HydroStat 3200-Plus (LED diagnostics) on Sentry, Sentinel and Galaxy GG cast-iron models, as documented in HydroStat 3200-Plus control instructions (Sentry / Sentinel / Galaxy GG LED diagnostics). Codes can differ between controller generations, so always check the manual that matches your unit.
- Slant/Fin Sentry (S-34 to S-150)
- Slant/Fin Sentinel (SE-70 to SE-210)
- Slant/Fin Galaxy (GXH/GXHA, GXH-II and GG Series)
Controller: HydroStat 3200-Plus (LED diagnostics). Source manual: see sources.
Why a code is not a diagnosis
A water-pressure or low-water code can mean a genuine leak or empty system, a failed expansion tank, a faulty fill valve, or a sensor problem. The appliance does not distinguish these.
Safe things to observe
- Read the pressure gauge and compare it with the normal cold-system pressure your installer set.
- Look for drips or wet spots near the appliance, pipes and the relief-valve discharge.
Do not
- Do not keep re-pressurizing a system that keeps losing water.
- Do not cap a relief-valve discharge pipe.
How professional service helps
- A technician finds and repairs the leak, checks the expansion tank and fill assembly, and verifies the sensor circuit.
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.
Low-water cutoff
A low-water cutoff is the safety device that stops a boiler from firing when there is not enough water inside it.
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 Slant/Fin Sentry (S-34 to S-150), Slant/Fin Sentinel (SE-70 to SE-210) and Slant/Fin Galaxy (GXH/GXHA, GXH-II and GG Series).
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
- HydroStat 3200-Plus control instructions (Sentry / Sentinel / Galaxy GG LED diagnostics) · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.