Weil-McLain EG-40
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.
Key figures
- Max input
- 125 MBH
- Max CSA output
- —
- AFUE
- —
- Min input
- —
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Weil-McLain EG-40 in practice
The EG-40 is rated 125 MBH CSA input and produces 106 MBH of DOE water heating capacity and 103 MBH in steam, with net AHRI ratings of 92 MBH water and 77 MBH steam covering 321 sq ft. It keeps the range's 84% water / 82% steam AFUE and ships at approximately 505 lb.
It uses the same atmospheric cast iron construction with Category I, B-vent vertical venting, a draft hood, an automatic vent damper and a 6" I.D. chimney collar. The connections are a 3" supply, 2-1/2" return, 1/2" gas and 3/4" relief, with 14.8 gal of water content and 9.8 gal to the steam waterline. The EG is discontinued in Canada; US sales continue as Series 6 and Series 7.
Best suited to
- Mid-size water or steam loads near 125 MBH
- Buildings with a 6" chimney and atmospheric venting
- Comparing EG generations across the Canadian/US split
Applicability and support
- Model number
- EG-40
- Canadian availability
- historical
- Production status
- discontinued
- 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 Weil-McLain. Units are shown with every value; notes flag conflicting sources or missing figures.
| Specification | Value | Note |
|---|---|---|
| Input | ||
| Input, maximum | 125 MBH | CSA input per the US EG Series 6/7 spec tables and the EG Series 7 manual ratings table (Table 20). |
| Output | ||
| DOE heating capacity, water | 106 MBH | Water heating capacity per manual Table 20; matches the CA discontinued page's output figure. |
| DOE heating capacity, steam | 103 MBH | Steam heating capacity per manual Table 20. |
| Net AHRI rating, water | 92 MBH | Net AHRI water rating based on a 1.15 piping and pick-up allowance per the manual ratings notes. |
| Net AHRI rating, steam | 77 MBH | Net AHRI steam rating based on a 1.333 pick-up allowance per the manual ratings notes. |
| Net AHRI steam rating, area | 321 sq ft | Steam square-foot rating per manual Table 20; the CA discontinued page's published range ends at 750 sq ft, which does not match the EG-75's 733 sq ft. |
| Efficiency | ||
| AFUE, water | 84 % | 84.0% AFUE in water per manual Table 21 and the US spec tables. |
| AFUE, steam | 82 % | 82.0% AFUE in steam per manual Table 21 and the US spec tables. |
| Venting and air | ||
| Venting | Category I, B-vent — vertical vent only, natural draft with draft hood and automatic vent damper; 6" I.D. chimney x 20 ft | Per the US spec tables (chimney size) and the CA discontinued page (Cat. 1, B-vent, vertical vent only). |
| Physical and connections | ||
| Supply connection | 3" | Supply tapping O is 1 x 3" on every EG/PEG size per the Series 7 manual connections section. |
| Return connection | 2-1/2" | Return tapping P is 1 x 2-1/2" on every EG/PEG size per the Series 7 manual connections section. |
| Gas connection | 1/2" | Gas connection F is 1/2" on EG/PEG-30 through -55 per the Series 7 manual. |
| Relief valve | 3/4" tapping | Water boilers use a 3/4" tapping on the side with a 30 psi relief valve; steam boilers use a 15 psi relief valve on a top tapping per the Series 7 manual. |
| Weight | 505 lb | Approximate shipping weight per the US spec tables and manual Table 20. |
| Operating limits and other | ||
| Boiler water content | 14.8 gal | Water content per manual Table 20. |
| Steam-to-waterline content | 9.8 gal | Steam-to-waterline water content per manual Table 20. |
Manuals
- EG Series 7 Boiler Manual, 550-100-225/0425550-100-225/0425 · 2025-04
Alerts documented for this model
- CONFIRM CONFIGURATION
- CONFIG MISMATCH
- AUTO LIMIT
- MANUAL LIMIT
- FALSE FLAME
- IGNITION FAULT
- FLAME LOST
- BOILER OUT OPEN
- BOILER OUT SHORT
- HARDWARE FAULT 1
- HARDWARE FAULT 2
- HARDWARE FAULT 3
- HARDWARE FAULT 4
- HARDWARE FAULT 5
- HARDWARE FAULT 6
- HARDWARE FAULT 7
- HARDWARE FAULT 8
- CH VOLTAGE HIGH
- DHW VOLTAGE HIGH
- SPILL SWITCH
- POWER (flashes once per second)
- Flash code 2
- Flash code 5
- Flash code 6
- ALL LED'S FLASHING
- Solid LWCO LED
- POWER + TSTAT/CIRC
- POWER + DAMPER
- POWER + FLAME
- DAMPER
- LIMIT
- FLAME
- LWCO
Frequently asked questions
What are the EG-40's ratings?
125 MBH CSA input, 106 MBH DOE water heating capacity, 103 MBH steam, 92 MBH net AHRI water, 77 MBH net AHRI steam (321 sq ft), and 84% water / 82% steam AFUE per the US spec tables and manual.
What are the EG-40's connections?
A 3" supply tapping, 2-1/2" return, 1/2" gas connection and 3/4" relief tapping, per the EG Series 7 manual connections section.
Is the EG-40 available in Canada?
No. The EG / EG Steam page on weil-mclain.ca is in the Discontinued menu; the US still sells the EG-40 as part of EG Series 6 and Series 7.
Questions about the Weil-McLain EG-40?
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.
Compare and explore
- Weil-McLain EG-35 vs EG-40Comparison
- Weil-McLain EG-40 vs EG-45Comparison
- Weil-McLain EG-30Same series
- Weil-McLain EG-35Same series
- Weil-McLain EG-45Same series
- Weil-McLain EG-50Same series
- Weil-McLain EG-55Same series
- Weil-McLain EG-65Same series
- Weil-McLain EG-75Same series
- EG / EG Steam series hub
- Buying guide
Sources and verification
- Weil-McLain Canada — EG / EG Steam (discontinued) · accessed September 9, 2026
- Weil-McLain — EG Series 7 Gas Boiler · accessed September 9, 2026
- EG Series 7 Boiler Manual 550-100-225/0425 · 550-100-225/0425 · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.