Lochinvar FTXL FTX500
The FTXL FTX500 fires 50 to 500 MBH with 489 MBH gross output and a 425 MBH AHRI net rating at 97.7% submittal thermal efficiency, keeping 2" water connections and 4" venting.
Key figures
- Max input
- 500 MBH
- Max CSA output
- —
- AFUE
- —
- Min input
- 50 MBH
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Lochinvar FTXL FTX500 in practice
The FTX500 adds 101 MBH of ceiling to the entry FTXL: the I&O ratings table (Series 120) lists 50 to 500 MBH input with 489 MBH gross output and a 425 MBH AHRI net water rating. The submittal prints 97.7% thermal efficiency for this size and 10:1 turndown, with an 11.9-gallon water content.
Connections stay at 2" water and 1" gas with a 4" air intake and 4" vent, vented in PVC, CPVC, polypropylene or AL29-4C stainless steel to 100 equivalent feet per the submittal, and the submittal lists a 504 lb shipping weight. Like the rest of the FTXL family it carries the SMART TOUCH control with CON·X·US, an ASME H stamp and the stainless steel fire-tube heat exchanger suited to variable-primary systems.
Best suited to
- Light commercial loads between the 400 and 500 MBH marks
- Plants that want 10:1 turndown with a 500 MBH ceiling
- Systems keeping 4" venting and 2" water piping at 500 MBH
Applicability and support
- Model number
- FTX500N
- 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 | 50 MBH | Per the I&O ratings table. |
| Heating input, maximum | 500 MBH | Per the I&O ratings table. |
| Output | ||
| Gross output | 489 MBH | Per the I&O ratings table. |
| Net AHRI water rating | 425 MBH | Per the I&O ratings table. |
| Efficiency | ||
| Efficiency (thermal) | 97.7 % | 97.7% thermal efficiency per the FTXL submittal. |
| Venting and air | ||
| Air inlet size | 4" | Per the I&O ratings table. |
| Vent size | 4" | Per the I&O ratings table. |
| Venting | Category IV sealed combustion; room air/direct vent in PVC, CPVC, polypropylene or AL29-4C stainless steel | Direct vent to 100 equivalent feet per the FTXL submittal and the product-page feature list; common vent kit available. |
| Physical and connections | ||
| Water content | 11.9 gal | Per the I&O ratings table. |
| Space-heating water connections | 2" | Per the I&O ratings table. |
| Gas connection | 1" | Per the I&O ratings table. |
| Shipping weight | 504 lb | Shipping weight per the FTXL submittal. |
Manuals
Alerts documented for this model
- Gas Pressure SW
- Flow Switch/LWCO
- Blocked Drain SW
- Anti-cycling
- Flame Fail Ign
- Flame Sequence
- Outlet ARHL
- Outlet MRHL
- Fan Low/High OR Fan Speed Low/High
- Sensor Open
- Sensor Shorted
- Louver Proving Sw
- Inlet Sensor Fault
- Outlet Sensor Fault
- Outlet Temp Diff
- Flue Sensor Fault
- Flue Temp Diff
- Flue Temp Limit
- Fatal Error
- Memory Error
- Flue Temp High
- Delta T High
- Outlet Temp High
- Rem Ctrl Flt
- Parameters Progr
- Service Blk
- Low 24 vac
- Watch Dog Error
- Write EEProm
- CRC Parameters
- No Error Stored
Frequently asked questions
What are the FTX500's ratings?
50 to 500 MBH of input with 489 MBH gross output and a 425 MBH AHRI net water rating, at 97.7% thermal efficiency per the FTXL submittal.
How does the FTX500 differ from the FTX400?
Maximum input rises from 399 to 500 MBH and gross output from 391 to 489 MBH; thermal efficiency per the submittal drops from 98.0% to 97.7%, and water content falls from 13.2 to 11.9 gallons.
Questions about the Lochinvar FTXL FTX500?
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 — FTXL Fire Tube Boiler (FTX400N) model page · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.