Laars Heating Systems · Mighty Therm2
Laars Mighty Therm2 MT2H0400
The Laars Mighty Therm2 MT2H0400 is a non-condensing commercial hydronic boiler rated 399,000 BTU/hr input and 340,000 BTU/hr output at 85.3% thermal efficiency.
Key figures
- Max input
- 399,000 BTU/hr
- Max CSA output
- 340,000 BTU/hr
- AFUE
- —
- Min input
- —
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Laars Mighty Therm2 MT2H0400 in practice
The MT2H0400 is the 399,000 BTU/hr size of the Mighty Therm2 200-400 line, documented in the Document 1564 submittal and the Document 1231 I&O. The submittal sizing table lists 399,000 BTU/hr input, 340,000 BTU/hr output, 85.3% thermal efficiency, a 3/4" gas connection, 1-1/2" water connections and the printed shipping weight.
The 200-400 line is the smaller sibling of the Mighty Therm2 500-2000 family and follows the same replacement-market design: modular construction separating the burner trays, gas train and blower assembly, two-stage firing, and fan-assisted Category I venting. The model structure prints 0200 as the 199,900 BTU/hr MT2V-only size, 0300 as 300,000 BTU/hr and 0400 as 399,900 BTU/hr (MT2H) or 400,000 BTU/hr (MT2V).
Best suited to
- Commercial hydronic loads near 399,000 BTU/hr input
- Buildings replacing a legacy Mighty Therm 175-400 boiler
- Retrofits that need the printed connection sizes for planning
Applicability and support
- Model number
- MT2H0400
- Canadian availability
- available
- Production status
- current
- 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 | 399,000 BTU/hr | Per the printed Mighty Therm2 submittal sizing table. |
| Output | ||
| Output | 340,000 BTU/hr | Per the printed Mighty Therm2 submittal sizing table. |
| Efficiency | ||
| Efficiency (thermal) | 85.3 % | Per the printed Mighty Therm2 submittal sizing table. |
| Venting and air | ||
| Venting | Category I fan-assisted; Category III with a listed vent system | Per the Mighty Therm2 I&O venting sections. |
| Physical and connections | ||
| Gas connection | 3/4" | Per the printed Mighty Therm2 submittal sizing table. |
| Water connection | 1-1/2" | Per the printed Mighty Therm2 submittal sizing table. |
| Shipping weight | 330 lb | Per the printed Mighty Therm2 submittal sizing table. |
| Operating limits and other | ||
| Firing | Two-stage, up to 4:1 | Printed on the Mighty Therm2 product page. |
Manuals
Alerts documented for this model
None documented yet.
Frequently asked questions
What are the Mighty Therm2 MT2H0400 ratings?
The Document 1564 submittal lists 399,000 BTU/hr input, 340,000 BTU/hr output and 85.3% thermal efficiency.
What sizes are in the Mighty Therm2 200-400 line?
The model structure prints MT2V0200 at 199,900 BTU/hr (volume water heater only), MT2V0300 at 300,000 BTU/hr, MT2H0400 at 399,900 BTU/hr and MT2V0400 at 400,000 BTU/hr.
Is the 200-400 line the same as the 500-2000 Mighty Therm2?
It is the smaller sibling of the same Mighty Therm2 family, covered by its own Document 1231 I&O and Document 1564 submittal.
Questions about the Laars Mighty Therm2 MT2H0400?
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 Mighty Therm2 MT2V0300 vs MT2H0400Comparison
- Laars Mighty Therm2 MT2H0400 vs MT2V0400Comparison
- Laars Mighty Therm2 MT2H 500Same series
- Laars Mighty Therm2 MT2H 750Same series
- Laars Mighty Therm2 MT2H 1000Same series
- Laars Mighty Therm2 MT2H 1250Same series
- Laars Mighty Therm2 MT2H 1500Same series
- Laars Mighty Therm2 MT2H 1750Same series
- Laars Mighty Therm2 MT2H 2000Same series
- Laars Mighty Therm2 MT2V0200Same series
- Laars Mighty Therm2 MT2V0300Same series
- Laars Mighty Therm2 MT2V0400Same series
- Mighty Therm2 series hub
- Buying guide
Sources and verification
- Laars — Mighty Therm2 200-400 product page · accessed September 9, 2026
- Mighty Therm2 200-400 Submittal Data, Document 1564 · 1564 · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.