NTI TRX Series II Combi Boiler | Gas Heating & On-Demand Hot Water
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Made-in-Canada Combi Boiler: Home Heating and On-Demand Hot Water in One Wall-Hung Unit
Tired of running out of hot water, or replacing both an old boiler and a water heater? The NTI TRX Series II combi boiler heats your home and supplies on-demand domestic hot water from a single wall-hung, high-efficiency condensing gas boiler. No separate water heater or storage tank to buy, power or make room for.
It's home-grown: the TRX Series II is made in Canada by NTI, which has built hydronic heating equipment in New Brunswick since the 1960s and is headquartered in Saint John, NB. The combination boiler comes in 3 sizes, runs on natural gas or propane, and works with in-floor radiant, baseboard, radiator and hydronic air handler heating.
Not sure which size fits your home? Contact us for a sizing recommendation.
Key features of the NTI TRX Series II combi boiler
- Made in Canada – built by NTI in New Brunswick, with technical support from Saint John, NB
- Available in 3 sizes:
- 106,000 BTU/hr heating, 114,000 BTU/hr hot water (TRX110C)
- 120,000 BTU/hr heating, 150,000 BTU/hr hot water (TRX150C)
- 197,000 BTU/hr heating (TRX199C)
- Heating and on-demand hot water in one unit, with a built-in hot water diverter valve
- High-efficiency condensing combi boiler – 95% AFUE on all three sizes
- Modulating burner with up to 11:1 modulation, so it runs only as hard as needed
- XTRATECH® stainless steel heat exchanger with large-diameter tubing
- Integrated ECM circulator pump
- NTI NET Wi-Fi – remote monitoring, error alerts and settings changes for you and your installer
- Natural gas or propane – propane conversion kits are available for every model
- Flexible venting – 2" vent up to 100 ft or 3" vent up to 150 ft
- ASME "H" stamped and certified to CSA 4.9
Safety warning: this is a gas appliance, and as such, requires certified, professional installation. Failure to properly install & commission a gas appliance can lead to serious damage, injury, or death.
How much hot water does an NTI TRX combi boiler make?
Hot water flow depends on how much the boiler has to heat the incoming water. In a Canadian winter, incoming water is cold, so use the 77°F rise column; in summer, the 35–45°F columns are closer.
| Model | 35°F rise | 45°F rise | 77°F rise |
|---|---|---|---|
| TRX110C | 5.9 GPM | 4.6 GPM | 2.7 GPM |
| TRX150C | 7.8 GPM | 6.1 GPM | 3.5 GPM |
| TRX199C | 10.5 GPM | 8.2 GPM | 4.8 GPM |
As a rough guide, a standard shower uses about 2 GPM. A home that runs two showers at once in winter will generally need the TRX150C or TRX199C.
NTI TRX combi boiler specifications
On a combi boiler, the model number follows the hot water input, not the heating input. The TRX150C heats like the 120,000 BTU/hr TRX120 and adds a 150,000 BTU/hr hot water side. Size the heating side to your home's heat loss.
| Model | Heating input (BTU/hr) | Hot water input (BTU/hr) | Net AHRI output, water (BTU/hr) | AFUE | Shipping weight |
|---|---|---|---|---|---|
| TRX110C | 11,200–106,000 | 11,200–114,000 | 85,000 | 95% | 83 lbs |
| TRX150C | 13,200–120,000 | 13,200–150,000 | 97,000 | 95% | 84 lbs |
| TRX199C | 19,700–197,000 | – | 160,000 | 95% | 135 lbs |
Hot water connections: 3/4" sweat / 3/4" male NPT. Gas connection: 3/4" male NPT. Gas supply: natural gas 3.5–10.5" W.C.; propane 8–13" W.C.
Combination boiler vs. boiler and water heater
A combination boiler saves space, removes standby losses from a storage tank, and gives endless hot water at its rated flow. A heat-only boiler with an indirect water heater is the better fit for homes with several bathrooms in use at once, or a large soaker tub. Compare the NTI TRX Series II heat-only boiler, or browse all combi boilers and gas boilers.
Need a complete system? Our custom pre-built boiler boards come piped and wired for multi-zone heating.
NTI TRX combi boiler FAQ
Where are NTI combi boilers made?
In Canada. The TRX Series II is manufactured in Canada by NTI, which has designed and built boilers in New Brunswick since the 1960s and is headquartered in Saint John, NB. NTI has been part of the Ariston Group since 2016.
How many showers can an NTI combi boiler run at once?
In winter (77°F rise), the TRX110C supports about one shower, the TRX150C one shower plus a tap, and the TRX199C about two showers at roughly 2 GPM each. In summer, flow rates are higher.
Can the NTI TRX combi boiler run on propane?
Yes. Every TRX Series II model ships for natural gas and can be converted to propane with NTI's propane conversion kit. The conversion must be done by a licensed gas fitter.
Can one combi boiler run in-floor heat and hot water?
Yes. The TRX combi supplies space heating to in-floor radiant, baseboard or radiators, and gives priority to domestic hot water when a tap opens.
What does an NTI combi boiler cost in Canada?
TRX Series II combi boilers start at $4,448 CAD for the TRX110C, with $95 terminal shipping across Canada. Installation, venting and controls are extra.
More information about the NTI TRX Series II
NTI TRX Series II product page
NTI TRX Series II submittal sheet (PDF)
Browse all NTI boilers, or shop more Canadian-made heating equipment.
