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 850 is the largest EX model: 824.5 MBH output against the EX 700's 679, with the same 97.0% thermal efficiency, 6" flue, 2½" NPT-M water connections and 120 equivalent feet of vent per side. It weighs 510 lb and needs a 21 USgpm minimum flow.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | IBC EX 700 | IBC EX 850 |
|---|---|---|
| CSA input, minimum | 70 MBH | 85 MBH |
| CSA input, maximum | 700 MBH | 850 MBH |
| CSA output | 679 MBH | 824.5 MBH |
| Thermal efficiency (ANSI/AHRI-1500) | 97 % | 97 % |
| Power use at full fire (less pumps) | 195 W | 228 W |
| Weight (empty) | 486 lb | 510 lb |
| Pressure vessel water content | 17.5 USG / 66.3 L | 16.4 USG / 62.0 L |
| Minimum boiler flow rate | 18 USgpm | 21 USgpm |
| Max. operating water pressure | 160 psig | 160 psig |
| Max. equivalent vent length, each side | 120 ft | 120 ft |
| Water connections | 2½" NPT-M | 2½" NPT-M |
| Flue / combustion air | 6" Schedule 40 flue / 4" Schedule 40 combustion air | 6" Schedule 40 flue / 4" Schedule 40 combustion air |
The EX 700 covers 70–700 MBH input and 679 MBH output; the EX 850 covers 85–850 MBH input and 824.5 MBH output. Both are rated 97.0% thermal efficiency to ANSI/AHRI-1500, so the larger model adds capacity without an efficiency penalty.
The connection group is identical: 6" Schedule 40 flue, 4" combustion air transitioning to 6" within three feet, 2½" NPT-M water connections and 120 equivalent feet of vent per side. Minimum boiler flow rises from 18 to 21 USgpm, against the shared 100 USgpm maximum.
The EX 850 weighs approximately 510 lb (231 kg) versus 486 lb (220 kg), has 99.88 ft² against 84.6 ft² of heating surface, and holds slightly less water at 16.4 USG versus 17.5 USG. Both are rated 160 psig with a supplied 50 psig relief valve and are approved to 12,000 ft.
IBC Technologies
The IBC EX 700 is a floor-standing commercial condensing boiler rated 70–700 MBH input and 679 MBH output at 97.0% thermal efficiency, with a 6" flue, 2½" NPT-M water connections and 120 equivalent feet of vent per side.
IBC Technologies
The IBC EX 850 is the largest EX Series boiler: 85–850 MBH input, 824.5 MBH output at 97.0% thermal efficiency, a 6" flue, 2½" NPT-M water connections and 120 equivalent feet of vent per side.
No. Both are rated 97.0% thermal efficiency to ANSI/AHRI-1500.
About 145.5 MBH: 824.5 MBH versus 679 MBH CSA output.
Yes: 6" flue, 4" combustion air transitioning to 6" within three feet, and 120 equivalent feet per side on both.
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.