Laars Heating Systems · Rheos (discontinued)
Laars Rheos+ RHHH 1200
The Laars Rheos+ RHHH 1200 is a discontinued condensing commercial hydronic boiler at 1,200,000 BTU/hr input, with a 6" vent outlet, 6" air inlet, 2-1/2" NPT water connections and a 1" NPT standard gas connection.
Key figures
- Max input
- 1,200,000 BTU/hr
- Max CSA output
- —
- AFUE
- —
- Min input
- —
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Laars Rheos+ RHHH 1200 in practice
The RHHH 1200 is the 1,200,000 BTU/hr condensing boiler size of Laars' Rheos+ line, documented in Document 1185B. The Figure 1 dimensional table lists a 6" vent outlet, a 6" air inlet, 2-1/2" NPT water inlet and outlet connections and a 1" NPT standard gas connection, and the vent/air table prints maximum runs of 50 linear feet with 5 elbows.
The model structure reads RH for the Rheos+ mid-sized commercial series, H for high-efficiency (condensing), H or V for hydronic or volume water, and the size digits; the RHHV water heater shares the same platform and connection table. Laars files the Rheos+ manual under Discontinued Documents, and the RHHH installs up to 10,000 ft without high-altitude modification.
Best suited to
- Commercial hydronic loads near 1,200,000 BTU/hr input
- Buildings with an installed Rheos+ RHHH that needs its connections identified
- Repair-or-replace decisions comparing Rheos+ with current Laars lines
Applicability and support
- Model number
- RHHH1200
- Canadian availability
- available
- 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 | 1,200,000 BTU/hr | The Document 1185B model identification prints 1,200,000 / 1,600,000 / 2,000,000 / 2,400,000 BTU/hr input for the four sizes. |
| Venting and air | ||
| Vent outlet connection | 6 in | Per the Figure 1 dimensional table in Document 1185B. |
| Air inlet connection | 6 in | Per the Figure 1 dimensional table in Document 1185B. |
| Vent / air run | 50 linear ft with 5 elbows | Per the Document 1185B vent/air table; intake and exhaust maximum runs are printed separately. |
| Physical and connections | ||
| Water inlet / outlet | 2-1/2" NPT | Per the Figure 1 dimensional table in Document 1185B. |
| Gas connection (standard pack) | 1" NPT | Per the Figure 1 dimensional table in Document 1185B; control packages B and E use a larger gas connection on some sizes. |
| Operating limits and other | ||
| Altitude | To 10,000 ft (universal altitude) | The model structure prints A = universal altitude 0-10,000 ft per Document 1185B. |
Alerts documented for this model
None documented yet.
Frequently asked questions
What is the Rheos+ RHHH 1200 input?
Document 1185B's model identification prints 1,200,000 BTU/hr input for the RHHH1200, with a 6" vent outlet and 2-1/2" NPT water connections.
Is the Rheos+ still sold?
Laars files the Rheos+ installation manual under Discontinued Documents; the current commercial Laars lines are the NeoTherm, NeoTherm XTR and MagnaTherm families.
Does the Rheos+ need high-altitude parts?
The model structure prints universal altitude 0-10,000 ft, so no high-altitude modification is required within that range.
Questions about the Laars Rheos+ RHHH 1200?
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 Rheos+ RHHH1200 vs RHHH1600Comparison
- Laars Rheos 1200 vs Laars Rheos+ RHHH 1200Comparison
- Laars Rheos+ RHHH 1200 vs Laars Rheos 1600Comparison
- Laars Rheos 1200Same series
- Laars Rheos 1600Same series
- Laars Rheos 2000Same series
- Laars Rheos 2400Same series
- Laars Rheos+ RHHH 1600Same series
- Laars Rheos+ RHHH 2000Same series
- Laars Rheos+ RHHH 2400Same series
- Rheos (discontinued) series hub
- Buying guide
Sources and verification
- Laars — Rheos+ product page · accessed September 9, 2026
- Rheos+ Installation and Operation Instructions, Document 1185B · 1185B · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.