Lochinvar · Knight Wall Mount (WHB)
Lochinvar Knight WHB199
The Knight WHB199 is the 199 MBH wall-hung Knight: 19.9 to 199 MBH input at 95% AFUE, stepping up to 1 1/4" water connections and 3" venting to 100 equivalent feet.
Key figures
- Max input
- 199 MBH
- Max CSA output
- —
- AFUE
- 95 %
- Min input
- 19.9 MBH
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Lochinvar Knight WHB199 in practice
The WHB199 lifts the wall-hung Knight to a nominal 199,000 BTU/h ceiling: input spans 19.9 to 199 MBH with 183 MBH of DOE heating capacity and a 159 MBH AHRI net rating at 95% AFUE. Its minimum fire of 19.9 MBH is the highest in the smaller half of the line, so the heat-loss calculation should genuinely need the ceiling before this size is chosen.
The larger input brings the first connection step: water fittings move from 1" to 1-1/4" and water content rises to 5.2 gallons, while the gas connection stays 1/2". Venting is 3" to 100 equivalent feet, and as a heating-only boiler it pairs with the Squire indirect tank for domestic hot water.
Best suited to
- Large homes and small multi-suite buildings whose load approaches 199 MBH
- Systems with an indirect tank sized for high hot-water recovery
- Projects where 1-1/4" near-boiler piping is already planned
Applicability and support
- Model number
- WHB199L
- Canadian availability
- available
- Production status
- current
- ROMA supplies
- Confirmed at consultation
- ROMA services
- Confirmed at consultation
- Warranty
- Series terms
Where ROMA provides on-site service
On-site service is currently offered in Greater Vancouver, BC, including Vancouver, Burnaby, Richmond, Surrey, Coquitlam, North Vancouver, West Vancouver, New Westminster, Port Coquitlam, Port Moody, Delta, Langley, Maple Ridge, Abbotsford, Chilliwack, White Rock, Pitt Meadows, Tsawwassen, Anmore, Lions Bay, Belcarra, Bowen Island, Mission. Everything else on this site is reference information you can use anywhere in Canada.
Specifications
Published specifications
Values as published by Lochinvar. Units are shown with every value; notes flag conflicting sources or missing figures.
| Specification | Value | Note |
|---|---|---|
| Input | ||
| Heating input, minimum | 19.9 MBH | Per the I&O ratings table. |
| Heating input, maximum | 199 MBH | Per the I&O ratings table. |
| Output | ||
| DOE heating capacity | 183 MBH | DOE heating capacity per the I&O ratings table. |
| AHRI net water rating | 159 MBH | Net AHRI rating based on a piping and pickup allowance of 1.15. |
| Efficiency | ||
| Efficiency (AFUE) | 95 % | 95% AFUE per the I&O ratings table. |
| Domestic hot water | ||
| Domestic hot water | Heating-only boiler | Pairs with the Squire indirect water heater or another indirect tank; the Knight is heating-only. |
| Venting and air | ||
| Venting | Category IV sealed combustion; PVC, CPVC, polypropylene or stainless steel | In Canada, plastic venting must be a ULC S636-certified system. |
| Max. equivalent vent/air length, 3" | 100 ft | Table 3D (air intake/vent piping sizes), I&O manual. |
| Physical and connections | ||
| Water content | 5.2 gal | Per the I&O ratings table. |
| Space-heating water connections | 1-1/4" | Per the I&O ratings table. |
| Gas connection | 1/2" | Per the I&O ratings table. |
Manuals
Alerts documented for this model
- Gas Pressure SW
- Flow Switch/LWCO
- Air Pressure SW
- Too Many Recyclings
- Anti-cycling
- Flame Fail Ign
- Flame Sequence
- Outlet ARHL
- Outlet MRHL
- Fan Speed
- Inlet, Outlet, or Flue Sensor Fault
- AUX Contact Sw
- Outlet Temp Diff
- Fatal Error
- Memory Error
- Flue Temp High / Flue Temp Limit
- Delta T High / Delta T Limit
- Outlet Temp High / Outlet Temp Limit
- Low 24 vac
- Watch Dog Error
- Write EEProm
- CRC Parameters
- No Error Stored
Frequently asked questions
What connections does the WHB199 use?
1-1/4" heating water connections with a 1/2" gas connection, and a 5.2-gallon water content, per the I&O ratings table.
Is the WHB199's minimum fire a concern?
At 19.9 MBH it is the highest minimum among the 055-199 sizes, so in a home whose load is well under the boiler's ceiling the unit will cycle more in mild weather. Sizing should follow a heat-loss calculation.
Questions about the Lochinvar Knight WHB199?
Describe what the boiler is doing and get a straight answer about the next step.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.
Compare and explore
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- Lochinvar Knight WHB155Same series
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- Knight Wall Mount (WHB) series hub
- Buying guide
Sources and verification
- Lochinvar — Knight Fire Tube Wall Mount (WHB055L) model page · accessed September 7, 2026
- Knight Wall Hung Fire Tube (WHB055-399) I&O Manual, Rev T · Rev T · accessed September 7, 2026
Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.