Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
Boilers.ca is a brand of ROMA Heating & Cooling · Licensed gas contractor LGA0202903
Comparison
Verdict in brief
The Noble NKC110 and NKC150 are the two smaller wall-hung Noble combis and share the 1" NPT space-heating and 3/4" DHW connections, 95.0% AFUE and on-demand hot water. The 150 fires 15 to 150 MBH against the 110's 11 to 110, adds 37 MBH of DOE capacity, and its 2" vent allowance drops from 100 to 60 equivalent feet.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Lochinvar Noble NKC110 | Lochinvar Noble NKC150 |
|---|---|---|
| Heating input, minimum | 11 MBH | 15 MBH |
| Heating input, maximum | 110 MBH | 150 MBH |
| DOE heating capacity | 102 MBH | 139 MBH |
| AHRI net water rating | 89 MBH | 121 MBH |
| Efficiency (AFUE) | 95 % | 95 % |
| Water content | 1.4 gal | 2 gal |
| Space-heating water connections | 1" NPT | 1" NPT |
| DHW water connections | 3/4" | 3/4" |
| Gas connection | 1/2" | 1/2" |
| Max. equivalent vent/air length, 2" | 100 ft | 60 ft |
| Max. equivalent vent/air length, 3" | 100 ft | 100 ft |
| Domestic hot water | On demand from the combi's DHW circuit | On demand from the combi's DHW circuit |
Both NKC models are wall-hung combis that produce domestic hot water on demand, with 1" NPT space-heating connections, 3/4" DHW connections, a 1/2" gas connection and the SMART CONTROL's diverter logic that Lochinvar's copy credits with eliminating the cold-water "sandwich" during DHW draws.
The 110 product page quotes DHW of up to 2.6 GPM at a 77°F rise; Lochinvar does not print a per-model DHW flow for the 150 in the same spec format, so the 150's extra input should be treated as heating-side headroom first. DOE capacity rises from 102 to 139 MBH between the two.
Venting is the measurable step: 2" pipe reaches 100 equivalent feet on the 110 but only 60 on the 150, with 3" at 100 feet on both. Water content grows from 1.4 to 2.0 gallons.
Lochinvar
The Noble NKC110 is the entry Noble wall-hung combi: 11 to 110 MBH input at 95.0% AFUE, rated for DHW of up to 2.6 GPM at a 77°F rise, with 3/4" DHW connections.
Lochinvar
The Noble NKC150 is the 150 MBH Noble wall-hung combi: 15 to 150 MBH space-heating input at 95.0% AFUE with 139 MBH DOE capacity and a 2-gallon water content.
Yes — both use 1" NPT space-heating connections and 3/4" DHW connections with a 1/2" gas connection, per the Noble ratings table.
When the heat-loss calculation approaches or exceeds 110 MBH. The NKC110 already covers the small-to-mid home and its DHW rating is quoted on the product page; the 150 adds heating headroom.
A consultation includes a heat-loss review so the size is right the first time.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.
Sources and verification
Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.