Weil-McLain Simplicity 110-C
The Simplicity 110-C is the smallest Simplicity: 110 MBH input, 100 MBH DOE heating capacity and 95% AFUE in a 16 x 20 x 34 inch combi that runs as a combi or heat-only boiler.
Key figures
- Max input
- 110 MBH
- Max CSA output
- 100 MBH
- AFUE
- 95 %
- Min input
- —
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Weil-McLain Simplicity 110-C in practice
The Simplicity 110-C is the entry size of Weil-McLain's newest Canadian residential boiler, which the CA page says can operate as a heat-only or as a combi unit: the stainless steel firetube heat exchanger pairs with a DHW brazed plate heat exchanger, so the same appliance can switch from heating-only duty to combi duty later.
At 110 MBH input it delivers 100 MBH of DOE heating capacity with an 87 MBH net AHRI rating at 95% AFUE, and the brochure publishes 2.9 GPM of DHW at a 70°F rise. It weighs 96 lb in the 16 x 20 x 34 inch cabinet with 3/4" heating connections, 1/2" DHW connections and 10:1 turndown.
Best suited to
- Smaller homes whose heat-loss calculation fits under 110 MBH
- Households that want to start heat-only and add combi hot water later
- Tight mechanical rooms — the 16" cabinet is the shortest Simplicity
Applicability and support
- Model number
- Simplicity 110-C
- Canadian availability
- available
- 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 | ||
| Input, maximum | 110 MBH | CSA input (maximum). |
| Output | ||
| DOE heating capacity | 100 MBH | DOE heating capacity at maximum input; the manuals also call this CSA Output. |
| Net AHRI water rating | 87 MBH | Net AHRI rating per the boiler manual ratings table. |
| Efficiency | ||
| Efficiency (AFUE) | 95 % | 95% AFUE per the boiler manual, brochure and CA page. |
| Domestic hot water | ||
| DHW flow at 70°F rise | 2.9 GPM | Per the Simplicity brochure ratings table. |
| Domestic hot water | Integrated combi: built-in DHW module with brazed plate heat exchanger | |
| Venting and air | ||
| Venting | 2" or 3" PVC, CPVC, polypropylene or stainless steel (Category IV) | Canada: install per CAN/CSA B149.1 or B149.2 with a ULC S636-compliant vent kit. |
| Max. equivalent vent/air length | 100 ft in 2" or 3" (vent and air each) | |
| Physical and connections | ||
| Weight | 96 lb | Boiler weight per the brochure and product spec table. |
| Dimensions (L x W x H) | 16" x 20" x 34" | |
| Gas connection | 1/2" NPT male | |
| Heating water connections | 3/4" NPT male | Boiler out and boiler in are 3/4" male NPT on the 110; DHW connections are 1/2" male NPT. |
| Operating limits and other | ||
| Turndown | 10:1 | 10:1 turndown ratio per the brochure and submittal. |
| Boiler water content | 2.2 gal | |
| Altitude rating | 2,000 ft | No modifications from sea level to 2,000 ft; the boiler auto-derates about 4% per 1,000 ft above sea level. |
| Fuel | Natural gas or propane | Propane requires a conversion kit per the CA product page. |
Manuals
- Simplicity Boiler Manual, 550-143-073/0125550-143-073/0125 · 2025-01
Alerts documented for this model
- Nothing shown on display screen and boiler will not respond to call for heat
- Nothing is shown in display screen and no other boiler components are operating
- Nothing is shown on display screen, but boiler is operating
- TEMP RISE
- COMM ERR
- CTRL FAULT
- LWCO OPEN
- RETURN > SUPPLY or BLR IN > BLR OUT
- BOILER OUT SNSR or FLUE SENSOR
- FLUE TOO HIGH
- MANUAL LIMIT or AUTO LIMIT
- HIGH TEMP LIMIT
- FALSE FLAME
- GAS RELAY 1-4
- IGN FAULT 1
- IGN FAULT 2
- FLAME LOSS
- AIR P-SW OPEN
- CLOSURE SWITCH
- CONFIG FAULT
- DHW OUT > BLR OUT
- CHIP FAULT
- 60F > RETURN
- FLUE 1 OPEN
- FLUE 1 SHORT
- FLUE 2 OPEN
- FLUE 2 SHORT
- BOILER OUT1 OPEN
- BOILER OUT1 SHRT
- BOILER OUT2 OPEN
- BOILER OUT2 SHRT
- BOILER IN OPEN
- BOILER IN SHORT
- BLOWER FAULT 1
- BLOWER FAULT 2
- BLOWER FAULT 3
- BLOWER FAULT 4
- WRONG J6
- A2D FAULT
- FLAME CIRCUIT
- SUPPLY SENSOR
- RETURN SENSOR
- DHW OUT SNSR
- OUTDOOR SENSOR
- EXCEEDED FLOW RATE
- REDUCED TGT - FLUE
- REDUCED TGT - BLR
- REDUCED TGT - FLOW
- CLOCK FAULT
- WRONG SOFTWARE
- LOW FLAME SHUTDOWN
- INTL DISPL COMM ERR
- PREHEAT ACTIVE
- CALIBRATE NEEDED
- CALIBRATE IS ACTIVE
Frequently asked questions
Is the Simplicity 110-C a combi boiler?
It is a combi-capable boiler: the DHW brazed plate heat exchanger is built in, and the unit can run as a combi or as a heat-only boiler, per the CA product page.
How much hot water does the 110-C deliver?
The brochure's DHW flow table lists 2.9 GPM at a 70°F temperature rise for the 110-C.
What connections does the 110-C use?
3/4" NPT male heating connections, 1/2" NPT male DHW connections, a 1/2" NPT gas connection and a 3/4" relief valve/air vent connection.
Questions about the Weil-McLain Simplicity 110-C?
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 Canada — Simplicity · accessed September 7, 2026
- Simplicity Boiler Manual 550-143-073/0125 · 550-143-073/0125 · accessed September 7, 2026
Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.