Lochinvar · Knight Floor Mount (KHB)
Lochinvar Knight KHB055
The Knight KHB055 is the floor-standing counterpart of the WHB055: 8.3 to 55 MBH input at 95% AFUE with the same fire-tube ratings, in a 157 lb floor cabinet.
Key figures
- Max input
- 55 MBH
- Max CSA output
- —
- AFUE
- 95 %
- Min input
- 8.3 MBH
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Lochinvar Knight KHB055 in practice
The KHB055 is the entry floor-standing Knight and the same boiler underneath as the WHB055: the I&O ratings tables are identical at this size — 8.3 to 55 MBH input, 51 MBH DOE heating capacity, a 44 MBH AHRI net rating and 95% AFUE. Where it differs is the floor-mounted frame, which suits basements without a wall rated for a hanging boiler.
The product page prints a 10:1 turndown bullet for the KHB055 while the WHB055 page prints 6.6:1 for the same firing range, so Boilers.ca relies on the 8.3 and 55 MBH inputs from the ratings table rather than the ratio. The boiler is heating-only with domestic hot water from an indirect tank, holds 2.3 gallons, connects on 1" fittings and vents in 2" to 80 equivalent feet or 3" to 100.
Best suited to
- Basement mechanical rooms better suited to a floor-standing boiler
- Smaller homes whose heat-loss calculation fits under 55 MBH
- Owners who want the Knight's fire-tube design without wall-mounting
Applicability and support
- Model number
- KHB055L
- 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 | 8.3 MBH | Per the I&O ratings table. |
| Heating input, maximum | 55 MBH | Per the I&O ratings table. |
| Output | ||
| DOE heating capacity | 51 MBH | DOE heating capacity per the I&O ratings table. |
| AHRI net water rating | 44 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, 2" | 80 ft | Table 3D (air intake/vent piping sizes), I&O manual. |
| Max. equivalent vent/air length, 3" | 100 ft | Table 3D (air intake/vent piping sizes), I&O manual. |
| Physical and connections | ||
| Water content | 2.3 gal | Per the I&O ratings table. |
| Space-heating water connections | 1" | Per the I&O ratings table. |
| Gas connection | 1/2" | Per the I&O ratings table. |
| Shipping weight | 157 lb | Shipping weight per the Lochinvar product page. |
| Height | 44.75 in | Floor-standing cabinet, per the Lochinvar product page. |
| Width | 22 in | Floor-standing cabinet, per the Lochinvar product page. |
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
Is the KHB055 the same rating as the WHB055?
Yes. The KHB and WHB I&O ratings tables print the same figures at the 055 size: 8.3 to 55 MBH input, 51 MBH DOE capacity and 95% AFUE.
What turndown does Lochinvar claim for the KHB055?
The KHB055 product page prints 10:1, while the WHB055 page prints 6.6:1 for the identical firing range. Boilers.ca shows the minimum and maximum inputs from the I&O table instead of the conflicting page claims.
Questions about the Lochinvar Knight KHB055?
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.