NTI Error Code Alert 90: Modulation output type was invalid (Boiler)
NTI error code Alert 90 on a boiler means: Modulation output type was invalid. It is also called NTI diagnostic code Alert 90.
Homeowner? What NTI code Alert 90 means for you
Usually minor Your boiler is reporting: Modulation output type was invalid. This code is usually informational or minor. The safe checks below often clear it; call us if it keeps showing up.
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.
- Look at the pressure gauge on the boiler. If it reads much lower than usual or near zero, or water is leaking, call a technician.
- Outside, make sure the intake and exhaust pipes or vent cap are not blocked by snow, ice, leaves or a nest.
- Check that the boiler gas valve is open (handle in line with the pipe).
- Try one reset: turn the power off for 30 seconds, then back on. If the code comes back, stop resetting and call a technician.
Call (647) 657-2977Book a service call
Licensed technicians serving Vaughan, Toronto and the GTA.
What does NTI error code Alert 90 mean?
Modulation output type was invalid.
Applies to: Trinity Tft60, Tft85, Tft110, Tft155, Tft175, Tft200, Tft250, Tft300, Tft399
NTI models that use code Alert 90
Tft60Tft60Tft85Tft85Tft110Tft110Tft154Tft155Tft175Tft200Tft201Tft250Tft285Tft300Tft340Tft399Tft399
Other NTI Boiler codes
NTI code Alert 90: homeowner questions
What does NTI code Alert 90 mean?
Modulation output type was invalid. Modulation output type was invalid.
Is it safe to keep using my boiler with code Alert 90?
Usually yes. Code Alert 90 is normally minor, but if it keeps coming back have it checked.
Can I reset NTI code Alert 90 myself?
You can try one reset (power off for 30 seconds, then on). If NTI code Alert 90 comes back, the cause is still there and a licensed technician should check it.
Who can fix NTI code Alert 90 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
- Blower not running NTI · Boiler
- Blower not running NTI · Boiler
- Blower runs at high speed with burner off NTI · Boiler
- Blower runs at high speed with burner off NTI · Boiler
- Boiler bangs or hisses; Lockout 81 delta T NTI · Boiler
- Boiler bangs or hisses; Lockout 81 delta T NTI · Boiler
- Burner not running on a call for heat NTI · Boiler
- Burner not running on a call for heat NTI · Boiler
- Checking spark and gas valve voltage during ignition NTI · Boiler
- Checking spark and gas valve voltage during ignition NTI · Boiler
- Circulator (CH or DHW) not running NTI · Boiler
- Circulator (CH or DHW) not running NTI · Boiler
- Clearing the low water cutoff lockout after filling NTI · Boiler
- Clearing the low water cutoff lockout after filling NTI · Boiler
- Combustion check procedure NTI · Boiler
- Combustion check procedure NTI · Boiler
- Display is blank NTI · Boiler
- Display is blank NTI · Boiler
- Display shows System Disconnected! constantly NTI · Boiler
- Display shows System Disconnected! constantly NTI · Boiler
- Dry run of the ignition sequence on new plastic vent NTI · Boiler
- Dry run of the ignition sequence on new plastic vent NTI · Boiler
- Flame failure check at commissioning NTI · Boiler
- Flame failure check at commissioning NTI · Boiler
- Ignition failure - Lockout 109 / Hold 110 NTI · Boiler
- Ignition failure - Lockout 109 / Hold 110 NTI · Boiler
- Lead-lag cascade setup shortcuts NTI · Boiler
- Lockout 138 - flame too low NTI · Boiler
- Lockout 138 - flame too low NTI · Boiler
- Low water cutoff / ILK OFF lockout (67) NTI · Boiler
- Low water cutoff / ILK OFF lockout (67) NTI · Boiler
- Low water cutoff test NTI · Boiler
- Low water cutoff test NTI · Boiler
- No power - checking 120 VAC and 24 VAC at the boiler NTI · Boiler
- No power - checking 120 VAC and 24 VAC at the boiler NTI · Boiler
- Outdoor temperature alert (Alert 248) NTI · Boiler
- Outdoor temperature alert (Alert 248) NTI · Boiler
- Program module restore - login password NTI · Boiler
- Reading the lockout and alert history NTI · Boiler
- Reading the lockout and alert history NTI · Boiler
- Running a pump by hand NTI · Boiler
- Running a pump by hand NTI · Boiler
- Stack limit lockout (Lockout 82) NTI · Boiler
- Stack limit lockout (Lockout 82) NTI · Boiler
- Turning the burner switch back on NTI · Boiler
- Turning the burner switch back on NTI · Boiler
Source: NTI Tft60-399 Installation and Operation Instructions (rev. 2012-04-09), Sec. 15.0 Troubleshooting, Table 15-4. 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.