Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Comparison
Verdict in brief
Weil-McLain EG-40 and Weil-McLain EG-45 are two non-condensing boilers from the Weil-McLain EG / EG Steam line. The Weil-McLain EG-40 is rated 125 MBH input, 106 MBH DOE heating capacity, water and 84% AFUE, water, and the Weil-McLain EG-45 is rated 150 MBH input, 127 MBH DOE heating capacity, water and 84% AFUE, water. Weil-McLain EG-45 lists 25 MBH more input than Weil-McLain EG-40 (150 MBH against 125 MBH). Both list the same published AFUE, water of 84%. Both list the same published shipping weight of 505 lb.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Weil-McLain EG-40 | Weil-McLain EG-45 |
|---|---|---|
| Input, maximum | 125 MBH | 150 MBH |
| Boiler water content | 14.8 gal | 14.8 gal |
| Weight | 505 lb | 505 lb |
| Venting | Category I, B-vent — vertical vent only, natural draft with draft hood and automatic vent damper; 6" I.D. chimney x 20 ft | Category I, B-vent — vertical vent only, natural draft with draft hood and automatic vent damper; 6" I.D. chimney x 20 ft |
| Gas connection | 1/2" | 1/2" |
| DOE heating capacity, water | 106 MBH | 127 MBH |
| DOE heating capacity, steam | 103 MBH | 124 MBH |
| Net AHRI rating, water | 92 MBH | 110 MBH |
| Net AHRI rating, steam | 77 MBH | 93 MBH |
| Net AHRI steam rating, area | 321 sq ft | 388 sq ft |
| AFUE, water | 84 % | 84 % |
| AFUE, steam | 82 % | 82 % |
| Supply connection | 3" | 3" |
| Return connection | 2-1/2" | 2-1/2" |
| Relief valve | 3/4" tapping | 3/4" tapping |
| Steam-to-waterline content | 9.8 gal | 9.8 gal |
Published ratings: the Weil-McLain EG-40 is rated 125 MBH input, 106 MBH DOE heating capacity, water and 84% AFUE, water; the Weil-McLain EG-45 is rated 150 MBH input, 127 MBH DOE heating capacity, water and 84% AFUE, water. Weil-McLain EG-45 lists 25 MBH more input than Weil-McLain EG-40 (150 MBH against 125 MBH). Both list the same published AFUE, water of 84%.
Both records print the same boiler water content (14.8 gal), shipping weight (505 lb), venting (Category I, B-vent — vertical vent only, natural draft with draft hood and automatic vent damper; 6" I.D. chimney x 20 ft) and gas connection (1/2"), per the cited sources.
Weil-McLain
The EG-40 raises the EG line to 125 MBH input with 106/103 MBH water/steam DOE heating capacity, 321 sq ft of steam coverage and 84%/82% AFUE; discontinued in Canada, still sold in the US as EG Series 6 and Series 7.
Weil-McLain
The EG-45 is the 150 MBH EG size: 127/124 MBH water/steam DOE heating capacity, 388 sq ft of steam coverage, 84%/82% AFUE and a 6" I.D. chimney — discontinued in Canada, current in the US.
The Weil-McLain EG-45 lists 150 MBH, against 125 MBH on the Weil-McLain EG-40, per the cited documentation.
Both list the same AFUE, water of 84%.
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.