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 NKB150 and NKB199 are the two largest Noble heating boilers: the 199 fires to 199 MBH with 185 MBH of DOE capacity against the 150's 139, holds 2.7 gallons against 2.0, and its 2" vent allowance drops to 50 equivalent feet while 3" stays at 100.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Lochinvar Noble NKB150 | Lochinvar Noble NKB199 |
|---|---|---|
| Heating input, minimum | 15 MBH | 19.9 MBH |
| Heating input, maximum | 150 MBH | 199 MBH |
| DOE heating capacity | 139 MBH | 185 MBH |
| AHRI net water rating | 121 MBH | 161 MBH |
| Efficiency (AFUE) | 95 % | 95 % |
| Water content | 2 gal | 2.7 gal |
| Space-heating water connections | 1" (sweat) | 1" (sweat) |
| Gas connection | 1/2" | 1/2" |
| Max. equivalent vent/air length, 2" | 60 ft | 50 ft |
| Max. equivalent vent/air length, 3" | 100 ft | 100 ft |
| Domestic hot water | Heating-only boiler | Heating-only boiler |
Both are wall-hung, heating-only Noble boilers rated 95.0% AFUE on 1" sweat connections with a 1/2" gas connection, run by the SMART CONTROL, and both take domestic hot water from an indirect tank because neither has DHW plumbing.
The 199 tops the NKB line for large homes and small multi-suite buildings: input reaches 199 MBH, DOE capacity 185 MBH and the AHRI net rating 161 MBH, against 150, 139 and 121 on the 150. Its minimum fire rises from 15 to 19.9 MBH.
The vent table tightens again at the 199 size: 2" pipe is allowed only to 50 equivalent feet while 3" remains at 100. Water content grows to 2.7 gallons, so the near-boiler volume is a little larger on the 199.
Lochinvar
The Noble NKB150 is the 150 MBH Noble heating boiler: 15 to 150 MBH input at 95.0% AFUE with 139 MBH DOE capacity, 1" sweat connections and 2" venting to 60 equivalent feet.
Lochinvar
The Noble NKB199 tops the Noble boiler line at 19.9 to 199 MBH input and 185 MBH DOE capacity, 95.0% AFUE, with 2" venting limited to 50 equivalent feet.
Maximum input rises from 150 to 199 MBH, DOE heating capacity from 139 to 185 MBH and the AHRI net rating from 121 to 161 MBH, all at 95.0% AFUE.
Yes, but only to 50 equivalent feet at the 199 size. The 3" option reaches 100 equivalent feet, so long runs use 3" pipe.
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.