Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Comparison
Verdict in brief
The EFW-285WBN and EFW-340WBN step up 55 MBH of input ceiling (285 to 340), 61 MBH of heating capacity (263 to 324) and 54 MBH of net AHRI water rating (228 to 282), with the 285 printing 95% AFUE and the 340 printing 95.4% thermal efficiency. The larger size moves from 3 in. to 4 in. venting (150 ft down to 100 ft maximum run), from 1-1/4 in. to 1-1/2 in. male water connections, and from a 180 lb to a 250 lb wall package.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | HTP EFW-285WBN | HTP EFW-340WBN |
|---|---|---|
| Input rate, minimum | 28.5 MBH | 39.9 MBH |
| Input rate, maximum | 285 MBH | 340 MBH |
| Heating capacity | 263 MBH | 324 MBH |
| Net AHRI rating, water | 228 MBH | 282 MBH |
| Water connections | 1-1/4" NPT male | 1-1/2" NPT male |
| Gas connection | 3/4" NPT male | 3/4" NPT male |
| Vent/air intake pipe diameter | 3" | 4" |
| Cabinet (H x W x D) | 33-3/8" x 21-1/4" x 18-5/8" | 36-5/8" x 25-1/4" x 20" |
| Approximate boiler weight with water | 180 lb | 250 lb |
| Boiler water content | 4.9 gal | 7.1 gal |
| Control | Advanced Honeywell Sola boiler controller with backlit screen | Advanced Honeywell Sola boiler controller with backlit screen |
| Warranty | 15-year limited warranty (5-year basic all components; registered installations extend pressure-vessel coverage through year 15) | 15-year limited warranty (5-year basic all components; registered installations extend pressure-vessel coverage through year 15) |
Both models are wall-mount condensing fire-tube boilers of HTP's current EFW Series, sharing the SA240-S43932 stainless steel ASME 'H' exchanger, the 10:1 turndown, the Honeywell Sola controller with outdoor reset, DHW priority, Modbus RTU and 8-boiler cascade, the 80 psi maximum operating pressure with a 30 psi ASME relief valve, and 120 V / 60 Hz power at less than 12 A.
The 285 fires 28.5–285 MBH for 263 MBH heating capacity and a 228 MBH net AHRI water rating at 95% AFUE; the 340 fires 39.9–340 MBH for 324 MBH and 282 MBH at 95.4% thermal efficiency (the 340 row prints thermal efficiency, not AFUE). The 285's lower 28.5 MBH minimum fire gives it more low-load headroom than the 340's 39.9 MBH floor.
The physical step is significant: 3 in. venting to 150 ft on the 285 versus 4 in. venting to 100 ft on the 340, 1-1/4 in. versus 1-1/2 in. male water connections, a 33-3/8 x 21-1/4 x 18-5/8 in. cabinet against 36-5/8 x 25-1/4 x 20 in., and 180 lb versus 250 lb with water (4.9 versus 7.1 gal water content). Both convert to propane with the documented kits.
The HTP EFW-285WBN is the 285 MBH class wall-mount model of the current EFW (Elite Firetube Wall Mount) line: 28.5 to 285 MBH input, 263 MBH heating capacity, a 228 MBH net AHRI water rating at 95% AFUE, a 3" vent connection and a 180 lb wall package with the Honeywell Sola control.
The HTP EFW-340WBN is the 340 MBH class wall-mount model of the current EFW (Elite Firetube Wall Mount) line: 39.9 to 340 MBH input, 324 MBH heating capacity, a 282 MBH net AHRI water rating at 95.4% thermal efficiency, a 4" vent connection and a 250 lb wall package with the Honeywell Sola control.
The EFW-340WBN: 39.9–340 MBH against 28.5–285 MBH on the 285. The 285's lower minimum fire (28.5 versus 39.9 MBH) is its advantage in mild weather.
No — the 285 uses 3 in. vent/air pipe with runs to 150 ft, while the 340 uses 4 in. pipe with runs to 100 ft per the official page.
The EFW-285WBN prints 95% AFUE; the EFW-340WBN prints 95.4% thermal efficiency. The table does not print AFUE for the 340.
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.