Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Comparison
Verdict in brief
The Simplicity 199-C is the only Simplicity that grows the cabinet — 20 x 20 x 34 in at 122 lb against the 150-C's 16-inch frame at 105 lb — in exchange for 199 MBH of input and the line's top DHW flow of 5.3 GPM at a 70°F rise.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Weil-McLain Simplicity 150-C | Weil-McLain Simplicity 199-C |
|---|---|---|
| Input, maximum | 150 MBH | 199 MBH |
| DOE heating capacity | 139 MBH | 184 MBH |
| Net AHRI water rating | 121 MBH | 160 MBH |
| Efficiency (AFUE) | 95 % | 95 % |
| Turndown | 10:1 | 10:1 |
| DHW flow at 70°F rise | 4 GPM | 5.3 GPM |
| Weight | 105 lb | 122 lb |
| Boiler water content | 3.1 gal | 3.8 gal |
| Venting | 2" or 3" PVC, CPVC, polypropylene or stainless steel (Category IV) | 2" or 3" PVC, CPVC, polypropylene or stainless steel (Category IV); PVC limited to 3" on the 199 |
The 150-C and 199-C both rate 95% AFUE with 10:1 turndown and the combi-or-heat-only flexibility, but the 199-C is the first Simplicity to outgrow the compact cabinet: it measures 20 x 20 x 34 inches and weighs 122 lb against 16 x 20 x 34 inches and 105 lb on the 150-C.
Capacity steps from 150 to 199 MBH input, 139 to 184 MBH of DOE heating capacity and 121 to 160 MBH net AHRI, while DHW flow rises from 4.0 to 5.3 GPM at a 70°F rise. Connections grow with the size: 1" male NPT heating and 3/4" male NPT DHW on the 199 against 3/4" and 1/2" on the 150.
The 199-C's venting rules change too: PVC is 3" only and 2" runs are limited to 50 equivalent feet, so most 199-C installations run 3" to the full 100 ft. Choose it when the heat-loss calculation or hot-water demand exceeds the 150-C's 139 MBH output and 4.0 GPM.
Weil-McLain
The Simplicity 150-C is the mid-size Simplicity: 150 MBH input, 139 MBH DOE heating capacity and 95% AFUE with 4.0 GPM of DHW at a 70°F rise in the same 16-inch cabinet.
Weil-McLain
The Simplicity 199-C is the largest Simplicity: 199 MBH input, 184 MBH DOE heating capacity and 95% AFUE with the line's top DHW flow of 5.3 GPM at a 70°F rise.
It is the only Simplicity in the 20 x 20 x 34 inch cabinet (122 lb); the 110-C and 150-C share the 16-inch cabinet at 96 and 105 lb.
5.3 GPM at a 70°F rise per the brochure, against 4.0 GPM on the 150-C.
Only to 50 equivalent feet, and PVC is limited to 3" on the 199 — most installations run 3" pipe to 100 ft.
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 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.