Lochinvar · Knight Floor Mount (KHB)
Lochinvar Knight KHB285
The Knight KHB285 tops the floor-standing Knight line at 28.5 to 285 MBH input and 264 MBH DOE capacity, 95% AFUE, with 3" venting to 50 feet or 4" to 100.
Key figures
- Max input
- 285 MBH
- Max CSA output
- —
- AFUE
- 95 %
- Min input
- 28.5 MBH
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Lochinvar Knight KHB285 in practice
The KHB285 is the largest floor-standing Knight, mirroring the wall-hung WHB285's ratings: 28.5 to 285 MBH of input with 264 MBH of DOE heating capacity and a 230 MBH AHRI net rating at 95% AFUE. Its application is genuinely large loads — big houses with radiator systems, shops or light-commercial spaces — because the 28.5 MBH minimum fire is already a large part-load for a typical home.
It connects on 1-1/4" heating fittings with a 1/2" gas connection and holds 4.9 gallons of water. The venting table offers 3" pipe to 50 equivalent feet or 4" to 100, which is the option that lets a long or indirect route work. Domestic hot water comes from an indirect tank, since the Knight is heating-only.
Best suited to
- Very large homes and light-commercial loads above 200 MBH
- Floor-standing plants with long vent routes served by 4" pipe
- Systems pairing the largest Knight with a large indirect tank
Applicability and support
- Model number
- KHB285L
- 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 | 28.5 MBH | Per the I&O ratings table. |
| Heating input, maximum | 285 MBH | Per the I&O ratings table. |
| Output | ||
| DOE heating capacity | 264 MBH | DOE heating capacity per the I&O ratings table. |
| AHRI net water rating | 230 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" | 50 ft | Table 3D (air intake/vent piping sizes), I&O manual. |
| Max. equivalent vent/air length, 4" | 100 ft | Table 3D (air intake/vent piping sizes), I&O manual. |
| Physical and connections | ||
| Water content | 4.9 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 is the firing range of the KHB285?
28.5 to 285 MBH of input per the KHB I&O ratings table, with 264 MBH DOE heating capacity, a 230 MBH AHRI net rating and 95% AFUE.
Can the KHB285 be vented in 4" pipe?
Yes — Table 3D allows 4" venting to 100 equivalent feet for the 285 size, with 3" limited to 50 equivalent feet.
Questions about the Lochinvar Knight KHB285?
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.
Sources and verification
- Lochinvar — Knight Fire Tube Floor Mount (KHB055L) model page · accessed September 7, 2026
- Knight Fire Tube Boiler (KHB055-285) I&O Manual, Rev M · Rev M · accessed September 7, 2026
Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.