Lochinvar · Knight (previous generation WH/KH)
Lochinvar Knight KHN155
The Lochinvar Knight KHN155 is a discontinued floor-standing fire-tube boiler rated 15.5-155 MBH input with 144 MBH gross output and a 125 MBH net AHRI water rating at 95% AFUE.
Key figures
- Max input
- 155 MBH
- Max CSA output
- —
- AFUE
- 95 %
- Min input
- 15.5 MBH
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Lochinvar Knight KHN155 in practice
The KHN155 is the 155 MBH floor-standing (KHN) size of the previous-generation Knight fire-tube boiler. Its archived I&O ratings table prints 15.5-155 MBH input, 144 MBH gross output, a 125 MBH net AHRI water rating, 95% AFUE, 3.2 gallons of boiler water, a 1" water connection, a 1/2" gas connection and a 3" vent size.
Lochinvar keeps the WHN and KHN support pages live under a "Series Discontinued" banner, and the WH 56-400 and KH 55-285 I&O manuals remain publicly hosted so owners can identify the unit and its control. The current Knight fire-tube generations are the WHB wall models and KHB floor models documented separately on Boilers.ca.
Best suited to
- Owners of an installed KHN155 identifying its ratings and manual
- Repair-or-replace decisions comparing a legacy Knight with the current WHB/KHB
- Contractors matching a legacy Knight to its archived I&O before service
Applicability and support
- Model number
- KHN155
- Canadian availability
- historical
- Production status
- discontinued
- ROMA supplies
- Confirmed at consultation
- ROMA services
- Confirmed at consultation
- Warranty
- Not verified
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 | 15.5 MBH | Per the legacy I&O ratings table. |
| Heating input, maximum | 155 MBH | Per the legacy I&O ratings table. |
| Output | ||
| Gross output | 144 MBH | Per the legacy I&O ratings table. |
| Net AHRI water rating | 125 MBH | Net AHRI rating based on a piping and pickup allowance of 1.15. |
| Efficiency | ||
| Efficiency (AFUE) | 95 % | AFUE per the legacy I&O ratings table. |
| Venting and air | ||
| Vent size | 3" | Per the legacy I&O ratings table; Canadian installations follow the manual's venting notes. |
| Physical and connections | ||
| Boiler water content | 3.2 gal | Per the legacy I&O ratings table. |
| Water connection | 1" | Per the legacy I&O ratings table. |
| Gas connection | 1/2" | Per the legacy I&O ratings table. |
Alerts documented for this model
None documented yet.
Frequently asked questions
What are the Knight KHN155 ratings?
The archived I&O ratings table prints 15.5-155 MBH input, 144 MBH gross output, a 125 MBH net AHRI water rating and 95% AFUE.
Is the WHN/KHN still sold?
No. Lochinvar's support pages carry a "Series Discontinued" banner for these Knight generations; the current fire-tube Knights are the WHB wall and KHB floor lines.
Where can I find the manual?
Lochinvar still hosts the WH 56-400 Installation & Operation Manual (Rev Y) and the KH 55-285 Installation & Operation Manual (Rev J) from the WHN and KHN support pages.
Questions about the Lochinvar Knight KHN155?
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
- Lochinvar Knight WHN055Same series
- Lochinvar Knight WHN085Same series
- Lochinvar Knight WHN110Same series
- Lochinvar Knight WHN155Same series
- Lochinvar Knight WHN199Same series
- Lochinvar Knight WHN285Same series
- Lochinvar Knight WHN399Same series
- Lochinvar Knight KHN055Same series
- Lochinvar Knight KHN085Same series
- Lochinvar Knight KHN110Same series
- Lochinvar Knight KHN199Same series
- Lochinvar Knight KHN285Same series
- Knight (previous generation WH/KH) series hub
- Buying guide
Sources and verification
- Lochinvar — Series Discontinued: Knight Fire Tube Boiler, Model KHN085 support page · accessed September 9, 2026
- Knight Fire Tube Boiler (KH 55-285) Installation & Operation Manual, Rev J · Rev J · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.