Weil-McLain · SlimFit (Commercial)
Weil-McLain SF1000
The Weil-McLain SF1000 is a current commercial condensing gas boiler in the SlimFit line: 167–1000 MBH input, 958 MBH gross output and a 1833 MBH net printed page rating at up to 96.1% combustion efficiency, with 6" or 8" venting and a sectional aluminium block heat exchanger.
Key figures
- Max input
- 1,000 MBH
- Max CSA output
- —
- AFUE
- —
- Min input
- 167 MBH
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Weil-McLain SF1000 in practice
The SF1000 is one of the five current SlimFit commercial condensing gas sizes documented on Weil-McLain's official SlimFit page. Its Technical Specs row prints 167–1000 MBH input, 958 MBH gross output and 1833 MBH in the net column (the official 1000–2000 submittal prints no per-size net column — both sources are recorded as printed). Venting is 6" or 8" with 100 ft or 150 ft allowable length in PVC, CPVC, PP, ABS or AL29-4C, on 2" NPT male gas at 3"–14" w.c. and 3" ASME Class 150 supply/return connections.
The boiler uses a sectional aluminium block heat exchanger with a stainless steel woven-fiber burner, sealed combustion, direct spark ignition, a variable-speed blower and a negative-pressure regulated gas valve; the submittal prints 96.1% combustion efficiency and null% thermal efficiency for this size. Control is the SlimFit platform with a 3.5 in. LCD screen, preset heating systems, 0-10 VDC output, Modbus standard and BACnet optional, cascading up to eight boilers with lead/lag rotation and up to 24 zone inputs/outputs.
Boilers.ca records the printed spec row for the SF1000 for commercial service planning. No official Canadian-sales statement was found on the US product page reviewed, so canadianStatus stays 'unknown'; commercial gas, combustion and venting work belongs with a licensed contractor against the model's own SlimFit boiler manual.
Best suited to
- 167–1000 MBH commercial condensing loads
- Plants wanting a sectional aluminium block boiler with cascade control
- Buildings planning 8-boiler lead/lag systems with up to 24 zones
Applicability and support
- Model number
- SF1000
- Canadian availability
- unknown
- Production status
- current
- 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 | ||
| Maximum input | 1,000 MBH | Maximum input per the official SlimFit Technical Specs table. |
| Minimum input | 167 MBH | Minimum input per the official SlimFit Technical Specs table. |
| Output | ||
| Gross output | 958 MBH | Gross output per the official SlimFit Technical Specs table. |
| Net AHRI rating | 1,833 MBH | Net AHRI rating as printed on the official page's Technical Specs table. |
| Efficiency | ||
| Combustion efficiency | 96.1 % | The SlimFit 1000–2000 submittal prints 'up to 96.1% combustion efficiency' among the standard features; no per-size efficiency column is printed for these sizes. |
| Thermal efficiency | Not printed per size | The 1000–2000 submittal does not print a per-size thermal-efficiency column; the series record keeps efficiency null. |
| Domestic hot water | ||
| Domestic hot water | Heating-only commercial boiler — domestic hot water comes from a separate indirect tank or water heater | |
| Venting and air | ||
| Vent/air diameter and length | 6" or 8"; 100 ft or 150 ft | Vent material PVC, CPVC, PP, ABS or AL29-4C per the Technical Specs table; certified Category II/IV venting. |
| Physical and connections | ||
| Gas connection and pressure | 2" NPT male; 3"–14" w.c. | Gas connection size and min/max gas pressure per the Technical Specs table. |
| Supply / return water connections | 3" ASME Class 150 | Supply/return water connection per the Technical Specs table. |
| Operating limits and other | ||
| Turn-down ratio | 6:1 | The SlimFit 1000–2000 submittal prints a modulating burner with 6:1 turndown; the 550–750 submittal documents the same sectional aluminium block platform. |
| Control | SlimFit control with 3.5" LCD screen; Modbus standard, BACnet optional | Per the 550–750 submittal: preset typical heating systems, 0-10 VDC output, up to 8-boiler cascading with lead/lag rotation, up to 24 zones. |
| Heat exchanger | Sectional aluminum block with stainless steel burner (woven steel fiber mesh) | Per the SlimFit 1000–2000 submittal standard features; sealed combustion, direct spark ignition, variable-speed blower and negative-pressure regulated gas valve. |
| Fuel | Natural gas; optional LP on the smaller sizes per the page | The official page notes optional LP on the smaller sizes. |
Manuals
- SlimFit 1000-2000 Boiler Manual, 550100561_1225 (Dec 2025)550100561_1225 · 2025-12
- SlimFit 1000–2000 Submittal
Alerts documented for this model
None documented yet.
Frequently asked questions
What are the SF1000's ratings?
167–1000 MBH input and 958 MBH gross output per the official Technical Specs table.
What venting does the SF1000 use?
6" or 8" vent/air connections with 100 ft or 150 ft allowable length in PVC, CPVC, PP, ABS or AL29-4C; the line is certified for Category II and Category IV venting.
How many SlimFit boilers can cascade?
Up to eight boilers with lead/lag rotation per the submittal, with multiple system functionality, series/parallel or smart sequencing and up to 24 zone inputs/outputs.
Questions about the Weil-McLain SF1000?
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.
Sources and verification
- Weil-McLain — SlimFit Commercial Condensing Gas Boiler (SF1000) · accessed September 9, 2026
- SlimFit 1000-2000 Boiler Manual, 550100561_1225 (Dec 2025) · 550100561_1225 · accessed September 9, 2026
- SlimFit 1000–2000 Submittal · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.