Lochinvar Line

Lochinvar Knight Boiler Water Heater — Specs, Features & Reviews

Earlier-platform Lochinvar combi boilers with 10-year heat exchanger warranty. 85/155/199 MBH sizes.

Updated May 2026 · Lochinvar Water Heaters

The KNIGHT line is Lochinvar\'s earlier-generation wall-hung fire-tube combi boiler — still in current sale alongside the newer NOBLE. Key advantage over NOBLE: 10-year heat exchanger warranty vs NOBLE\'s 5-year.

The lineup

  • WHN85 — 85 MBH, 3.4 GPM DHW. Smallest Knight combi; for smaller homes or replacement of cast-iron boilers
  • WHN155 — 155 MBH, 4.5 GPM DHW. Volume mid-size Knight combi
  • WHN199 — 199 MBH, 5.0 GPM DHW. Largest Knight combi

Why KNIGHT still exists alongside NOBLE

  • 10-year heat exchanger warranty — twice as long as NOBLE\'s 5-year
  • More size options — 85 MBH unit not available in NOBLE
  • Proven service record — older platform with established parts availability and contractor experience
  • Compatible spare-parts inventory for contractors who service older Knights

Specs

ModelBTUDHW GPM at 70°F riseAFUE
WHN8585,0003.495%
WHN155155,0004.595%
WHN199199,0005.095%

Features

  • Stainless fire-tube heat exchanger
  • 10:1 turndown modulation
  • Built-in circulator
  • Direct vent PVC
  • Outdoor reset capable
  • SMART SYSTEM control

Install

Same as NOBLE — see install guide. WHN85 may use ½" gas line if short runs; WHN155 and WHN199 typically ¾"+.

Warranty

  • 10-year heat exchanger
  • 1-year parts
  • 1-year labor
  • Annual professional service required

When to choose KNIGHT over NOBLE

  • Want the longer 10-year heat exchanger warranty
  • Need 85 MBH size (smallest available)
  • Working with a contractor who has more Knight experience
  • Replacing an existing Knight (parts/service familiarity)

Bottom line

KNIGHT is the legacy-but-current Lochinvar combi. Longer heat exchanger warranty than NOBLE, smaller available sizing options, and a proven track record. New installs splitting between NOBLE and KNIGHT — contractor preference and warranty priority drive the choice.