Troubleshooting / Steam boiler

Steam Boiler Troubleshooting

The most common steam boiler problems on the plant floor, with the likely causes and the fix for each. Part of the OEE Lab troubleshooting directory.

Not your exact symptom?

Describe it in the symptom finder and search the whole directory.

Open the symptom finder

Problems on this page:

Low steam pressureCarryover or wet steamFrequent low-water lockoutBurner lockoutHigh fuel useWater hammer in the steam linesScale or corrosion from feedwaterSafety valve liftingBlowdown problems

Low steam pressure

Hits OEE: Availability

Symptoms: Cannot hold header pressure, process heating slow.

Burner/firing fault
Check burner operation, fuel supply and combustion controls.
Excess load or steam leaks
Find and fix steam leaks/failed traps; review demand.
Scaled heat surfaces
Descale; correct feedwater treatment.

Prevention: Feedwater treatment, steam-trap surveys, burner maintenance.

Carryover or wet steam

Hits OEE: Quality

Symptoms: Water carried with the steam, water hammer, wet product or equipment downstream.

Water level too high
Check the level control set points.
High dissolved solids or foaming
Control blowdown and the water treatment.
Sudden load swings
Smooth the steam demand where possible.
Separator or steam valve fault
Check the separator and its trap.

Prevention: Boiler water tested on the schedule the water treatment plan sets.

Frequent low-water lockout

Hits OEE: Availability

Symptoms: Repeated low-water trips and resets, unstable level.

Feedwater pump or valve fault
Check the feed pump, valves and feedwater supply.
Level control fouled
Clean and test level controls/probes; blow down the column.
Leaks or excess blowdown
Find and fix steam/water leaks; tune blowdown.

Prevention: Feed-system checks, level-control maintenance, leak surveys.

Burner lockout

Hits OEE: Availability

Symptoms: The burner fails to light or locks out and the boiler stops.

Flame sensor dirty or failed
Clean or replace the sensor.
Ignition fault
Check the igniter and transformer.
Fuel supply pressure low
Check the fuel supply.
Air proving switch fault
Check the switch and the fan.

Prevention: Burner servicing by a qualified technician on the maker's schedule.

High fuel use

Hits OEE: Performance

Symptoms: More fuel per tonne of steam than before.

Scale on the water side
Fix water treatment and descale.
Soot on the fire side
Clean the tubes.
Air to fuel ratio drifted
Have the combustion tuned by a qualified technician.
High blowdown, steam leaks or failed traps
Check blowdown, leaks and traps.

Prevention: Fuel per tonne of steam tracked.

Water hammer in the steam lines

Hits OEE: Availability

Symptoms: Banging in steam lines, damaged fittings and gaskets.

Condensate not drained
Check the traps and drip legs.
Valves opened too fast at start-up
Warm lines slowly.
Carryover from the boiler
Fix the carryover.

Prevention: Start-up procedure written for the steam system.

Scale or corrosion from feedwater

Hits OEE: Availability

Symptoms: Scale on tubes, pitting, tube failures.

Softener exhausted
Regenerate and check the softener.
Deaerator not at temperature
Check the deaerator.
Chemical dosing off
Check the dosing.

Prevention: Water tests on the schedule the treatment plan sets.

Safety valve lifting

Hits OEE: Availability

Symptoms: The safety valve opens or simmers.

Pressure control set too close to the safety valve
Check the control settings.
Pressure switch failure
Test the switches.
Leaking valve seat
Have the valve serviced by a competent person.

Prevention: Never gag or adjust a safety valve; tests by a competent person.

Blowdown problems

Hits OEE: Availability

Symptoms: The blowdown valve leaks, the blowdown vessel discharges hot water or steam, water use rises.

Blowdown valve seat worn
Service or replace the valve.
Automatic blowdown control fault
Check the controller and its conductivity probe.
Blowdown vessel vent blocked
Clear the vent.
Blowdown run longer than needed
Follow the blowdown the treatment plan sets.

Prevention: Blowdown valves checked for passing on the route.

Guidance only. Always follow lockout/tagout and your site's safe-work procedures, and verify against OEM manuals before acting.

Related equipment guides: industrial oven · tunnel pasteuriser · autoclave · induction furnace · retort · reverse osmosis system · water softener · thermal oil heater · steam trap · pellet mill · corrugator · keg washer · jet dyeing machine · steam peeler · paper machine · EPS moulding machine · clean steam generator · smokehouse · brewhouse · deaerator · tyre curing press

Stop the same fault coming back

Recurring steam boiler stops usually trace to a cause you cannot see by hand. The partner we recommend is Fabrico: it tracks OEE and downtime live from PLCs, IoT sensors or AI cameras; where cameras are fitted, the video of a stop sits next to its machine data so the cause can be reviewed; and a technician opens the work order from the stop in the same system. Data is hosted in the AWS EU region, and Fabrico and the company behind it hold ISO/IEC 27001, ISO/IEC 20000-1 and ISO 9001.

Book a Fabrico demo
The directory stays free.

Related tools: full troubleshooting directory · OEE calculator · downtime cost · MTBF / MTTR · glossary

Methods that cut recurring stops: the six big losses · root cause analysis · preventive vs predictive maintenance · TPM · SMED & changeover