Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
Boilers.ca is a brand of ROMA Heating & Cooling · Licensed gas contractor LGA0202903
Comparison
Verdict in brief
The EX 500 adds about 97 MBH of output (485 vs 388 MBH) over the EX 400 while dropping slightly in thermal efficiency (97.5% vs 97.9%) and gaining 27 lb. Both keep the 4" flue, 2" NPT-M water connections and 170 equivalent feet of vent per side.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | IBC EX 400 | IBC EX 500 |
|---|---|---|
| CSA input, minimum | 40 MBH | 50 MBH |
| CSA input, maximum | 399 MBH | 500 MBH |
| CSA output | 388 MBH | 485 MBH |
| Thermal efficiency (ANSI/AHRI-1500) | 97.9 % | 97.5 % |
| Power use at full fire (less pumps) | 150 W | 210 W |
| Weight (empty) | 414 lb | 441 lb |
| Pressure vessel water content | 13.5 USG / 51.1 L | 12.4 USG / 46.9 L |
| Minimum boiler flow rate | 10 USgpm | 12 USgpm |
| Max. operating water pressure | 160 psig | 160 psig |
| Max. equivalent vent length, each side | 170 ft | 170 ft |
| Water connections | 2" NPT-M | 2" NPT-M |
| Flue / combustion air | 4" Schedule 40 flue / 4" Schedule 40 combustion air | 4" Schedule 40 flue / 4" Schedule 40 combustion air |
The EX 400 covers 40–399 MBH input and 388 MBH output; the EX 500 covers 50–500 MBH input and 485 MBH output. Both use the 4" Schedule 40 flue / 4" combustion-air group with 170 equivalent feet of vent per side and 2" NPT-M water connections, so the site requirements are nearly identical.
Efficiency is highest on the smaller model: 97.9% thermal to ANSI/AHRI-1500 on the EX 400 against 97.5% on the EX 500. Power draw rises from 150 W to 210 W at full fire, and the minimum boiler flow from 10 to 12 USgpm, against the shared 100 USgpm maximum.
The EX 500 is heavier at approximately 441 lb (200 kg) versus 414 lb (188 kg) and holds slightly less water, 12.4 USG against 13.5 USG, while heating surface grows from 55.3 ft² to 72.9 ft². Both are rated 160 psig with a supplied 50 psig relief valve and are approved to 12,000 ft.
IBC Technologies
The IBC EX 400 is the smallest floor-standing EX Series commercial boiler: 40–399 MBH input, 388 MBH output, 97.9% thermal efficiency, 4" venting to 170 equivalent feet and 2" NPT-M water connections.
IBC Technologies
The IBC EX 500 is a floor-standing commercial condensing boiler rated 50–500 MBH input and 485 MBH output at 97.5% thermal efficiency, with 4" venting to 170 equivalent feet and 2" NPT-M water connections.
The EX 400 at 97.9% thermal efficiency; the EX 500 is 97.5%.
Yes: 4" Schedule 40 flue and combustion air with 170 equivalent feet per side on both.
About 97 MBH: 485 MBH versus 388 MBH CSA output.
A consultation includes a heat-loss review so the size is right the first time.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.
Sources and verification
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.