Laars Heating Systems · Mini-Therm JX
Laars JX200
The Laars JX200 is the largest Mini-Therm JX boiler: a non-condensing gas-fired residential hydronic boiler at the 200 size top of the 50-200 MBTU/h range, with LED-based analog diagnostics and no digital display.
Key figures
- Max input
- 200 MBH
- Max CSA output
- —
- AFUE
- —
- Min input
- —
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Laars JX200 in practice
The JX200 closes the Mini-Therm JX range at the 200 size — the largest model column in Document 1478C's parts tables and the ceiling of the 50-200 MBTU/h line. It carries the same non-condensing gas-fired hydronic design, natural-gas and propane parts sets and altitude groupings as the smaller JX sizes.
With no digital display, the JX200 is diagnosed through Section 11.C's numbered troubleshooting table and Section 11.D's LED flow charts. As the largest non-condensing residential JX it is the size chosen when the calculated load genuinely reaches the top of the range — beyond it, Laars' condensing lines or commercial products take over.
Best suited to
- Largest homes in the JX range whose heat-loss calculation approaches 200 size
- Heating-only plants wanting the full non-condensing JX ceiling
- Owners who prefer the JX line's analog serviceability at maximum capacity
Applicability and support
- Model number
- JX200
- 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 | ||
| Maximum input (as printed) | 200 MBH | Top of the Mini-Therm JX size range — the manual's parts tables close at the 200 size (Document 1478C, cover: sizes 50-200 MBTU/h). |
| Domestic hot water | ||
| Domestic hot water | None built in — a DHW relay kit and DHW panel assembly are listed in the manual's replacement-parts sections | |
| Operating limits and other | ||
| Fuel | Natural gas or propane | NG and LP orifices, pilot parts and regulator springs are listed in the manual parts sections with altitude groupings. |
| Error reporting | No digital display or numeric codes — Section 11.C troubleshooting table and Section 11.D flow charts use the control LEDs (TEMP ACTIVE, LOW WATER, HI TEMP, TARGET) | |
Alerts documented for this model
None documented yet.
Frequently asked questions
What is the largest Mini-Therm JX size?
The 200 size (JX200) is the top of the line: the manual covers sizes 50-200 MBTU/h and its parts tables end at the 200 model column.
Does the JX200 differ from the JX150 in servicing?
No — the two share the same design, manual (Document 1478C), parts families scaled by size, and the LED and flow-chart diagnostic approach. Only capacity and the matching parts differ.
Can the JX200 run on propane?
Yes — the manual's parts sections list propane orifices, pilot parts and regulator springs, with altitude groupings to 10,000 ft for propane. Conversion is licensed gas-fitting work.
Questions about the Laars JX200?
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
- Laars Heating Systems — official site · accessed September 7, 2026
- Laars — contact (Laars Canada, 9 Brigden Gate, Halton Hills, Ontario) · accessed September 7, 2026
Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.