Laars Heating Systems · Mascot LX (discontinued)
Laars Mascot LX MLX 125
The Laars Mascot LX MLX 125 is a discontinued wall-mounted modulating boiler rated 125,000 BTU/h input and 118,750 BTU/h output at 95% AFUE, with 3/4" NPT water connections and a 126 lb shipping weight. An MLXC combi version of this size is rated 3.1 gpm at a 75°F rise.
Key figures
- Max input
- 125,000 BTU/h
- Max CSA output
- 118,750 BTU/h
- AFUE
- 95 %
- Min input
- —
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Laars Mascot LX MLX 125 in practice
The MLX 125 is one of the seven MLXH wall-mounted modulating boiler sizes in Laars' discontinued Mascot LX line, documented in the Document 1285 installation and operation manual. The sizing table lists it at 125,000 BTU/h input and 118,750 BTU/h output at 95% AFUE, on a 1/2 in NPT gas connection and 3/4" NPT water connections, with a 126 lb shipping weight.
The size is also offered as the MLXC combi, rated 3.1 gpm at a 75°F rise with a 1/2 in NPT DHW connection and a 133 lb shipping weight. The Mascot LX nomenclature reads M LX for the series, H or C for hydronic or combination, W for wall-hung, the three-digit size, N or P for fuel, A for altitude (4% per 1,000 ft derate above 2,000 ft), a revision digit, an options code (X standard or L low-water cut-off) and a pump option (N with pump). Laars files Document 1285, its French version and the parts list and warranty under Discontinued Documents.
Best suited to
- Homes whose heat-loss calculation matches 125,000 BTU/h input
- Households that can use the MLXC combi version of this size for domestic hot water
- Retrofits replacing a wall-hung boiler with a 95% AFUE modulating unit
Applicability and support
- Model number
- MLX 125
- Canadian availability
- historical
- Production status
- discontinued
- ROMA supplies
- Confirmed at consultation
- ROMA services
- Confirmed at consultation
- Warranty
- Not verified
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 Laars Heating Systems. Units are shown with every value; notes flag conflicting sources or missing figures.
| Specification | Value | Note |
|---|---|---|
| Input | ||
| Input | 125,000 BTU/h | Per the Mascot LX I&O manual's sizing table (Document 1285). |
| Output | ||
| Output | 118,750 BTU/h | Per the Mascot LX I&O manual's sizing table. |
| Efficiency | ||
| Efficiency (AFUE) | 95 % | 95% AFUE printed for every MLX size in the sizing table. |
| Domestic hot water | ||
| Domestic hot water | MLXC combi available at this size — domestic water at 3.1 gpm at a 75°F rise through the combination boiler, 1/2" NPT DHW connection | |
| DHW output at 75°F rise | 3.1 GPM | MLXC combi output per the sizing table. |
| Physical and connections | ||
| Gas connection | 1/2" NPT | Per the sizing table. |
| Water connection | 3/4" NPT | Per the sizing table. |
| Boiler shipping weight | 126 lb | Per the sizing table. |
| Combi shipping weight | 133 lb | Per the sizing table. |
| Operating limits and other | ||
| High altitude | De-rate 4% per 1,000 ft above 2,000 ft | Per the manual's model nomenclature notes. |
| Fuel | Natural gas or propane | Natural gas or propane; the nomenclature uses N for natural gas and P for propane. |
Alerts documented for this model
None documented yet.
Frequently asked questions
What are the MLX 125's ratings?
The Mascot LX sizing table (Document 1285) lists 125,000 BTU/h input and 118,750 BTU/h output at 95% AFUE, with 3/4" NPT water connections and a 126 lb shipping weight.
Is there a combi version of the MLX 125?
Yes. The MLXC 125 combi is rated 3.1 gpm at a 75°F rise with a 1/2 in NPT DHW connection and a 133 lb shipping weight.
Is the Mascot LX discontinued?
Yes. Laars' Mascot LX product URL returns 404 and the Document Library files the 1285 I&O, parts list and warranty under Discontinued Documents.
Questions about the Laars Mascot LX MLX 125?
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
- Laars Mascot LX MLX 100 vs MLX 125Comparison
- Laars Mascot LX MLX 125 vs MLX 150Comparison
- Laars Mascot LX MLX 50Same series
- Laars Mascot LX MLX 75Same series
- Laars Mascot LX MLX 100Same series
- Laars Mascot LX MLX 150Same series
- Laars Mascot LX MLX 175Same series
- Laars Mascot LX MLX 220Same series
- Mascot LX (discontinued) series hub
- Buying guide
Sources and verification
- Laars Heating Systems — official site · accessed September 7, 2026
- Laars — contact (Laars Canada, 9 Brigden Gate, Halton Hills, Ontario) · accessed September 7, 2026
- Laars — Document Library (Discontinued Documents category) · accessed September 9, 2026
- Laars — Discontinued Documents · accessed September 9, 2026
- Laars — Mascot LX Installation and Operation Instructions, Document 1285 · 1285 · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.