NOBLE is Lochinvar\'s current-generation wall-hung condensing combi boiler. One unit provides both space heating and domestic hot water for hydronic-heated homes. NOBLE replaces the older KNIGHT platform for new installs while KNIGHT remains available for compatibility.
The lineup
- NKC110-N — 110 MBH, 4.0 GPM DHW at 70°F rise. For 1-2 bathroom homes
- NKC199-N — 199 MBH, 5.4 GPM DHW at 70°F rise. Volume Lochinvar combi. For 2-3 bathroom homes
Key features
- 95% AFUE seasonal efficiency
- 10:1 turndown — modulates from 10% to 100% fire rate
- Stainless fire-tube heat exchanger — corrosion-resistant for condensing operation
- DHW priority with diverter valve and plate heat exchanger
- Built-in circulator for the heating loop
- Direct vent via 2"/3" PVC sidewall
- Outdoor reset built-in (sensor optional)
- Cascade-capable for multi-boiler installs (commercial / large residential)
NOBLE vs KNIGHT — which to pick
| NOBLE (NKC) | KNIGHT (WHN) | |
|---|---|---|
| Generation | Current (2018+) | Earlier (still current sale) |
| Heat exchanger warranty | 5 years | 10 years |
| AFUE | 95% | 95% |
| Sizing range | 110, 199 MBH | 85, 155, 199 MBH (more sizes) |
| Cost (installed) | $4,500-6,500 | $4,500-6,800 |
| Pick when | Want current platform, OK with 5-yr warranty | Want 10-yr warranty OR need 85 MBH size |
DHW sizing
| Model | DHW GPM at 70°F rise | Concurrent fixtures |
|---|---|---|
| NKC110 | 4.0 GPM | 1 shower + 1 sink |
| NKC199 | 5.4 GPM | 1 shower + 1 sink + 1 dishwasher |
Install requirements
See install guide. Key:
- Wall-mount on structure rated for 95-120 lb
- 2" or 3" PVC direct vent — sidewall or concentric
- ¾" gas line minimum for NKC110; ¾"-1" for NKC199
- Condensate drain to floor or pump
- 120V outlet
- Expansion tank sized to system volume
- Auto-fill valve recommended
Warranty
- 5-year heat exchanger
- 1-year parts
- 1-year labor
- Annual professional service required to keep heat exchanger warranty active
Bottom line
NOBLE is the current Lochinvar combi for new installs. Choose NKC110 for 1-2 bathroom homes, NKC199 for 2-3 bathroom homes. If 10-year heat exchanger warranty matters more than current-platform features, choose KNIGHT instead.