Lochinvar FTXL FTX725
The FTXL FTX725 fires 103.6 to 725 MBH with 705 MBH gross output and a 613 MBH AHRI net rating at 97.2% submittal thermal efficiency, stepping to 2-1/2" water connections and a 6" vent.
Key figures
- Max input
- 725 MBH
- Max CSA output
- —
- AFUE
- —
- Min input
- 103.6 MBH
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Lochinvar FTXL FTX725 in practice
The FTX725 is the first FTXL size that steps its plant connections: the I&O ratings table lists 103.6 to 725 MBH input with 705 MBH gross output and a 613 MBH AHRI net water rating at 97.2% submittal thermal efficiency, with a 17.2-gallon water content. Water connections grow to 2-1/2" while the gas connection stays 1", and the air intake stays 4" while the vent steps to 6".
Turndown is 7:1 per the submittal (matching the 103.6 MBH minimum input). The unit vents in PVC, CPVC, polypropylene or AL29-4C stainless steel to 100 equivalent feet per the submittal, carries the SMART TOUCH control with CON·X·US and an ASME H stamp on the stainless steel fire-tube platform, and the submittal lists a 575 lb shipping weight.
Best suited to
- Commercial heating plants with design-day loads between 600 and 725 MBH
- Projects already planning 2-1/2" near-boiler piping
- Systems comfortable with a 103.6 MBH minimum fire
Applicability and support
- Model number
- FTX725N
- 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 | 103.6 MBH | Per the I&O ratings table. |
| Heating input, maximum | 725 MBH | Per the I&O ratings table. |
| Output | ||
| Gross output | 705 MBH | Per the I&O ratings table. |
| Net AHRI water rating | 613 MBH | Per the I&O ratings table. |
| Efficiency | ||
| Efficiency (thermal) | 97.2 % | 97.2% thermal efficiency per the FTXL submittal. |
| Venting and air | ||
| Air inlet size | 4" | Per the I&O ratings table. |
| Vent size | 6" | 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 | 17.2 gal | Per the I&O ratings table. |
| Space-heating water connections | 2-1/2" | Per the I&O ratings table. |
| Gas connection | 1" | Per the I&O ratings table. |
| Shipping weight | 575 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 FTX725's ratings?
103.6 to 725 MBH of input with 705 MBH gross output and a 613 MBH AHRI net water rating at 97.2% thermal efficiency per the FTXL submittal.
How does the FTX725 connect?
2-1/2" water connections, a 1" gas connection, a 4" air intake and a 6" vent per the I&O ratings table, with a 17.2-gallon water content.
Questions about the Lochinvar FTXL FTX725?
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.