Who makes NTI boilers?
NTI stands for NY Thermal Inc., a company once known as the New Yorker Boiler Company. Malcolm Dennison founded it in 1967, and its head office and factory sit on Drury Cove in Saint John, New Brunswick. In 2016 Italy's Ariston Thermo took a controlling interest, and today Ariston Group lists NTI among its regional brands. NTI's safety notices now come from Ariston Canada Inc., but the boilers still carry the NTI name.
For an owner, the useful part is the paper trail. NTI keeps its discontinued models, its recall notices and a serial-number date guide on its website, which makes an older boiler easier to identify and support. Our boiler and radiant heat page covers how we work on hydronic systems in general.
How do you read an NTI boiler model number?
NTI model numbers follow a simple pattern. The letters name the series and the digits track the size: an FTVN085 fires anywhere from 8,500 to 85,000 BTU per hour. A C on the end means a combi that also makes domestic hot water, as in the FTVN150C or TRX199C. TFTN models are the next generation of the TFT, and Compass models start with NC.
The discontinued boilers are worth knowing too. NTI lists the Trinity Ti, the T and Tx series, the TFT, the FTV and the Vmax as discontinued. Knowing which one you have tells us which parts, venting rules and control settings apply before we open the cabinet.
NTI repairs we see in Minnesota
Recalls and notices first. NTI's March 2025 recall covers certain TRX150, TRX199 and TRX199C Series II boilers whose burner door studs can loosen during operation. A 2018 recall covered a grommet seal inside selected Tft boilers. We check your model and serial against NTI's list before we start.
Lockouts in cold snaps. A plugged condensate trap, a frozen condensate line or a sidewall termination frosted over at -20°F can stop any condensing boiler, and the fix is at the drain or the vent, not in the control. Clear a lockout once; if it comes back, find the cause.
Pressure, air and pumps. The FTVN Series II and Compass have an ECM pump built in, and the TFTN runs up to three heating zones on its own. Low system pressure, air at high points and a waterlogged expansion tank show up as cold zones and lockouts. Kettling or rumbling usually means restricted flow or scale; our post on boiler banging and kettling noises explains the sounds.
Propane. NTI publishes propane conversion instructions for the FTVN Series II and Compass. Homes outside the gas lines need that conversion done right and checked with a combustion analyzer, and our post on propane heating costs covers the fuel side.
Which NTI boiler fits your heating system?
NTI's wall-hung boilers, the FTVN, TRX and TFTN, do their best work on systems that can run cooler water for long stretches: radiant slabs, heated garages, lake-home additions and radiators on outdoor reset. Their wide modulation lets them idle along on a mild October day instead of cycling on and off. Our radiant floor vs baseboard guide explains why water temperature matters.
The Compass is NTI's answer for the old basement boiler room. It stands on the floor, pipes out either side and has primary/secondary piping and a pump built in, so it can go where a cast-iron boiler sat in a Minneapolis bungalow without building a wall to hang it on. The old loop still needs flushing, and the house still needs a vent route and a condensate drain. A condensing NTI won't run a steam system; steam needs a steam boiler.
Booking NTI service
Call 612-429-3465 from 7am to 9pm, any day of the week. No-heat calls get priority. A service call is a $79 trip charge, waived when you approve the repair, with a written, flat-rate price before we start and a 1-year parts-and-labor warranty on the repair. If replacement makes more sense, installs carry a 2-year labor warranty on top of the manufacturer's parts warranty and normally need a mechanical permit. A photo of the rating plate helps us bring the right parts.
NTI questions
Is my NTI boiler part of a recall?
Check NTI's safety recalls page against your model and serial number. The March 2025 recall covers certain TRX150, TRX199 and TRX199C Series II boilers whose burner door studs can loosen during operation. A July 2018 recall covered a grommet seal inside selected Tft boilers, and a February 2026 notice calls for an upgrade kit on FTG boilers built before January 8, 2026. The model and serial are on the silver rating plate on the side of the cabinet.
How do I tell how old my NTI boiler is?
Read the serial number on the silver rating plate on the left or right side of the boiler. On pre-2010 models such as the T and Ti, it starts with the two-digit year, so a 09Ti serial is a 2009 boiler. For boilers built in 2019 and later, NTI's date-code guide shows the build date inside the serial, as month, day and year or as year and day of the year. For models in between, NTI's tech support decodes it.
My NTI boiler locked out. Can I reset it?
Once. NTI's support line handles basic steps like resetting a lockout, and NTI posts a video on clearing one on the TRX and FTVN Series II. If it locks out again, something caused it: a plugged condensate trap, a frosted vent termination, low water pressure or a gas supply problem. Resetting it every morning can hide a combustion problem, so call us instead.
Is an NTI combi enough hot water for my house?
It depends on the model. NTI rates the FTVN110C at 2.7 gallons per minute with a 77°F temperature rise, the FTVN150C at 3.6 and the FTVN199C at 4.8. In late winter Minnesota tap water comes in colder, so the rise is bigger and the flow you get drops. Two showers and a dishwasher at once can outrun the smaller models, and a heat-only NTI with an indirect tank handles bigger demand.
Do I need to register an NTI boiler?
Yes. NTI has online product registration and offers extended warranty programs. The Compass carries a limited lifetime heat exchanger warranty per NTI, and other terms vary by model, so read the warranty sheet for yours. NTI says its contractors can look up warranty details by serial number through its partner portal, which helps when you bought a house with the boiler already in it.
Sources
- NTI official site ntiboilers.com