NTI Error Code 01 01: Overheat (CH circuit) (Boiler)
NTI error code 01 01 on a boiler means: Overheat (CH circuit). It is also called NTI diagnostic code 01 01.
Critical severityBoilerTRX
Homeowner? What NTI code 01 01 means for you
Stop and call Your boiler is reporting: Overheat (CH circuit). This code is a safety shutdown. Turn the boiler off and call a licensed technician. Do not keep resetting it. If you smell gas, leave the house and call your gas utility or 911 from outside.
Safe things you can check yourself
- Check the thermostat: right mode (Heat or Cool), set a few degrees past room temperature, and fresh batteries if it uses them.
- Make sure the unit has power: its on/off switch (often looks like a light switch near the unit) is ON and the breaker in the electrical panel is not tripped.
Call (647) 657-2977Book a service call
Licensed technicians serving Vaughan, Toronto and the GTA.
What does NTI error code 01 01 mean?
Central heating circuit overheat. Clears with a manual reset.
Applies to: TRX150
Safety: Gas, electrical and refrigerant work must be done by a licensed technician. Turn off power and gas before servicing, never bypass a safety control, and always follow the manufacturer's manual for your exact model.
NTI models that use code 01 01
TRX085TRX110CTRX150TRX199TRX199C
Other NTI Boiler codes
NTI code 01 01: homeowner questions
What does NTI code 01 01 mean?
Overheat (CH circuit). Central heating circuit overheat. Clears with a manual reset.
Is it safe to keep using my boiler with code 01 01?
No. Code 01 01 is a safety shutdown, so keep the boiler off until a licensed technician has checked it.
Can I reset NTI code 01 01 myself?
Do not keep resetting it. Repeated resets can hide a safety problem; a licensed technician needs to find the cause.
Who can fix NTI code 01 01 near me?
Aurora Star Tech Inc. repairs NTI boilers in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.
Homeowner help: Boiler Not Heating: What to Check
Troubleshooting guides
- Condensing/corrosion of conventional boiler All brands · Boiler
- No heat or some zones cold All brands · Boiler
- Noise All brands · Boiler
- Poor heat / circulation All brands · Boiler
- Relief valve weeps every cycle / pressure climbs All brands · Boiler
- Short cycling / wasted fuel All brands · Boiler
- Symptoms of air in system All brands · Boiler
- Uneven heating All brands · Boiler
- Won't fire All brands · Boiler
- 3-way valve motor must be disconnected for heating-only use on TRX150 / TRX199 NTI · Boiler
- Access installer parameters in the boiler menu NTI · Boiler
- Access the low voltage wiring connections NTI · Boiler
- Access the technical menu NTI · Boiler
- Adjust parallel shift from home screen NTI · Boiler
- Antifreeze selection NTI · Boiler
- Auto Boost behaviour NTI · Boiler
- Blocking errors versus lockout errors NTI · Boiler
- Blower not running NTI · Boiler
- Blower runs at high speed with burner off NTI · Boiler
- Boiler bangs or hisses; Lockout 81 delta T NTI · Boiler
- Burner not running on a call for heat NTI · Boiler
- Canada vent installation requirements NTI · Boiler
- Canadian vent installation requirements NTI · Boiler
- Carbon monoxide detector placement NTI · Boiler
- Central heating (CH) setpoint adjustment NTI · Boiler
- Ceramic fiber dust in the combustion chamber NTI · Boiler
- Check inlet gas pressure at the boiler NTI · Boiler
- Check the burner NTI · Boiler
- Check the condensate drain NTI · Boiler
- Check water and gas piping NTI · Boiler
- Checking spark and gas valve voltage during ignition NTI · Boiler
- Circulator (CH or DHW) not running NTI · Boiler
- Clean the condensate trap NTI · Boiler
- Clean the DHW filter (combi models only) NTI · Boiler
- Clean the heat exchanger and combustion chamber NTI · Boiler
- Clean the heat exchanger combustion chamber NTI · Boiler
- Clear an ignition lockout NTI · Boiler
- Clearing the low water cutoff lockout after filling NTI · Boiler
- Combustion check at elevation above 2000 ft NTI · Boiler
- Combustion check procedure NTI · Boiler
- Condensate drain setup NTI · Boiler
- Condensate float switch NTI · Boiler
- Condensate line blocked (display error) NTI · Boiler
- Connect 120 V power for CH and DHW circulators NTI · Boiler
- Control panel buttons and display layout NTI · Boiler
- Day and night room setpoints NTI · Boiler
- Display icons and what they mean NTI · Boiler
- Display is blank NTI · Boiler
- Display shows System Disconnected! constantly NTI · Boiler
- Do not add cold make-up water to a hot boiler NTI · Boiler
- Do not adjust excess flow valve screws without analyzer NTI · Boiler
- Do not fire the boiler before filling NTI · Boiler
- Do not use solvents or operate with missing parts NTI · Boiler
- Domestic hot water (DHW) setpoint adjustment NTI · Boiler
- Drain the domestic hot water system and indirect tank NTI · Boiler
- Drain the heating system NTI · Boiler
- Dry run of the ignition sequence on new plastic vent NTI · Boiler
- Excess flow valve (EFV) in the gas line NTI · Boiler
- Exhaust vent and intake pipe installation rules NTI · Boiler
- Exhaust vent slope, support and terminations NTI · Boiler
- Flame failure check at commissioning NTI · Boiler
- Flame signal too low or flame loss NTI · Boiler
- Freeze protection is off when the boiler has no power NTI · Boiler
- Functional test after maintenance NTI · Boiler
- Gas leak check before startup NTI · Boiler
- Gas line installation requirements NTI · Boiler
- Glycol limits for DHW and IWH loops NTI · Boiler
- Heating-only use on TRX150 / TRX199: disconnect the 3-way valve motor NTI · Boiler
- Ignition failure - Lockout 109 / Hold 110 NTI · Boiler
- Inform the user after service NTI · Boiler
- Install exhaust vent or intake pipe into the boiler collar NTI · Boiler
- Installation checklist sign-off (commissioning) NTI · Boiler
- Key installation checks before start-up NTI · Boiler
- Lead-lag cascade setup shortcuts NTI · Boiler
- Limit CO when adjusting high fire, low fire or the gas valve NTI · Boiler
- Lockout 138 - flame too low NTI · Boiler
- Lockout reset limit NTI · Boiler
- Low water cutoff / ILK OFF lockout (67) NTI · Boiler
- Low water cutoff test NTI · Boiler
- Massachusetts venting requirements NTI · Boiler
- Navigate the user menu NTI · Boiler
- No power - checking 120 VAC and 24 VAC at the boiler NTI · Boiler
- Open the complete technical menu NTI · Boiler
- Operate the primary pressure relief valve (test) NTI · Boiler
- Outdoor temperature alert (Alert 248) NTI · Boiler
- Overheat cutoff and lockout at 212°F NTI · Boiler
- Piping without an external central heating circulator (TRX150 / TRX199 and TRX199C) NTI · Boiler
- Power-on and operating modes NTI · Boiler
- Pre-start water chemistry and freeze protection NTI · Boiler
- Prepare the boiler before replacing components NTI · Boiler
- Pressure test the gas supply NTI · Boiler
- Primary/secondary piping for TRX150 / TRX199 with separate central heating circulator NTI · Boiler
- Program module restore - login password NTI · Boiler
- Purge function access NTI · Boiler
- Reading the lockout and alert history NTI · Boiler
- Reducing vent to 2 in on 150 models NTI · Boiler
- Remove the cabinet cover and control panel housing NTI · Boiler
- Replace the burner NTI · Boiler
- Replace the fan and mixer NTI · Boiler
- Replace the gas valve NTI · Boiler
- Replace the main heat exchanger NTI · Boiler
- Replace the main PCB NTI · Boiler
- Reset after a lockout NTI · Boiler
- Running a pump by hand NTI · Boiler
- Scald risk at DHW temperatures NTI · Boiler
- Scalding water when draining NTI · Boiler
- Service clearances and combustible spacing NTI · Boiler
- Set date and time manually NTI · Boiler
- Sidewall concentric or low profile exhaust location NTI · Boiler
- Solvent cement cure and cleanup before start-up NTI · Boiler
- Stack limit lockout (Lockout 82) NTI · Boiler
- Start test mode for manual firing NTI · Boiler
- Summer/winter changeover operation NTI · Boiler
- System water fill, purge and test NTI · Boiler
- Test mode and test function buttons NTI · Boiler
- Thermostat circuit check (no voltage allowed) NTI · Boiler
- Turning the burner switch back on NTI · Boiler
- Use the correct gas diaphragm and mixer for the fuel NTI · Boiler
- User maintenance checks NTI · Boiler
- Vent connection with PVC NTI · Boiler
- Vent diameter by model NTI · Boiler
- Vent insulation and material rules near the boiler NTI · Boiler
- Venting below an overhang (sidewall snorkel) NTI · Boiler
- Venting below grade and outdoor vent piping NTI · Boiler
- Venting material and adapter rules NTI · Boiler
- View the error history NTI · Boiler
- View the last 10 boiler errors NTI · Boiler
- Wire a room thermostat NTI · Boiler
- Wiring safety: label wires and keep 120 V away from control wiring NTI · Boiler
- Zone valve wiring for valve-based systems NTI · Boiler
Source: NTI TRX150 manual, p. 90. Written in our own words as a summary; always check the original manual.
General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.