Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Comparison
Verdict in brief
The Noble NKB080 and NKB110 are the two smallest Noble heating boilers and are nearly twins: both fire down near 8.3-11 MBH, vent 2" or 3" to 100 feet, use 1" sweat connections and rate 95.0% AFUE. The 110 lifts the ceiling from 80 to 110 MBH with 102 MBH of DOE capacity.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Lochinvar Noble NKB080 | Lochinvar Noble NKB110 |
|---|---|---|
| Heating input, minimum | 8.3 MBH | 11 MBH |
| Heating input, maximum | 80 MBH | 110 MBH |
| DOE heating capacity | 74 MBH | 102 MBH |
| AHRI net water rating | 64 MBH | 89 MBH |
| Efficiency (AFUE) | 95 % | 95 % |
| Water content | 1.2 gal | 1.4 gal |
| Space-heating water connections | 1" (sweat) | 1" (sweat) |
| Gas connection | 1/2" | 1/2" |
| Max. equivalent vent/air length, 2" | 100 ft | 100 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 at 95.0% AFUE with 1" sweat water connections (the NPT fittings belong to the combis), a 1/2" gas connection and the SMART CONTROL display of text-name faults. Domestic hot water comes from an indirect tank such as the Squire.
The ratings step is small: minimum fire rises from 8.3 to 11 MBH while maximum input goes from 80 to 110 MBH and DOE capacity from 74 to 102 MBH. In a low-load home the NKB080 tracks mild weather a little more closely.
Venting is identical at these sizes — 2" or 3" pipe, each to 100 equivalent feet — and water content stays near 1.2-1.4 gallons, so the decision reduces to whether the heat-loss calculation ever needs more than 80 MBH of input.
Lochinvar
The Noble NKB080 is the smallest Noble heating boiler: 8.3 to 80 MBH input at 95.0% AFUE with a 1.2-gallon water content, 1" sweat connections and 2" or 3" venting to 100 feet.
Lochinvar
The Noble NKB110 is the 110 MBH Noble heating boiler: 11 to 110 MBH input at 95.0% AFUE with 102 MBH DOE capacity, sharing the Noble ratings table with the NKC110 and NCF110 combis.
They share the Noble wall-hung platform, 1" sweat connections and 2"/3" venting to 100 feet; the published differences are the firing range (8.3-80 versus 11-110 MBH) and water content (1.2 versus 1.4 gallons).
When the heat-loss calculation plus indirect-tank recovery demand more than 80 MBH of input. Below that load the NKB080 delivers the same 95.0% AFUE at a lower minimum fire.
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.