Weil-McLain GV90+4
The GV90+4 steps the cast iron line to 105 MBH input and 97 MBH DOE heating capacity at 91.2% AFUE, keeping the 30-3/4" cabinet length with 4.7 gallons of boiler water.
Key figures
- Max input
- 105 MBH
- Max CSA output
- 97 MBH
- AFUE
- 91.2 %
- Min input
- —
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Weil-McLain GV90+4 in practice
The GV90+4 fires at 105 MBH CSA input for 97 MBH of DOE heating capacity and an 84 MBH net AHRI rating at 91.2% AFUE. It shares the 30-3/4" cabinet length of the GV90+3 but grows to 4.7 gallons of boiler water and a 353 lb shipping weight.
As with every Series 2 GV90+, it is a Category IV boiler vented in 3" pipe to 100 ft, carries the built-in low water cut-off, and reports through the IBC's indicator lights and POWER-LED flash codes. Domestic hot water is produced by an indirect tank such as the Weil-McLain Aqua Plus.
Best suited to
- Homes whose heat-loss calculation sits around 100 MBH
- High-temperature baseboard or radiator systems needing mid-size cast iron
- Owners who want GV90+'s wide waterways in a 30-3/4" cabinet
Applicability and support
- Model number
- GV90+4
- 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 | 105 MBH | CSA input (maximum). |
| Output | ||
| DOE heating capacity | 97 MBH | DOE heating capacity at maximum input; the manuals also call this CSA Output. |
| Net AHRI water rating | 84 MBH | Net AHRI rating per the boiler manual ratings table. |
| Efficiency | ||
| Efficiency (AFUE) | 91.2 % | 91.2% AFUE. |
| Domestic hot water | ||
| Domestic hot water | Heating-only boiler; domestic hot water via an indirect tank or separate appliance | |
| Venting and air | ||
| Venting | 3" PVC, CPVC, polypropylene or stainless steel (Category IV); 3" pipe on all GV90+ sizes | Canada: install per CAN/CSA B149.1 or B149.2 with a ULC S636-compliant vent kit. |
| Max. equivalent vent/air length | 100 ft (vent and air each) | |
| Physical and connections | ||
| Weight | 353 lb | Approx. shipping weight per the boiler manual and brochure. |
| Cabinet length | 30-3/4" | |
| Gas connection | 1/2" NPT | |
| Heating water connections | 1" NPT supply (male) and 1" NPT return (female) | Minimum recommended pipe 1". |
| Operating limits and other | ||
| Boiler water content | 4.7 gal | |
| Fuel | Natural gas or propane | Propane requires a conversion kit per the CA product page. |
Manuals
- GV90+ Series 2 Boiler Manual, 550-143-010/0324550-143-010/0324 · 2024-03
Alerts documented for this model
- POWER LED flashes once per second
- POWER LED 2 flashes
- POWER LED 3 flashes
- POWER LED 4 flashes
- POWER LED 5 flashes
- POWER LED 6 flashes
- POWER light flashing alone
- POWER and TSTAT/CIRC lights flashing
- POWER and PRESS SWITCH lights flashing
- POWER and FLAME lights flashing
- FLAME lights flashing
- Solid LWCO light
- LWCO light flashing alone
- TSTAT/CIRC light flashing alone
- LIMIT light flashing alone
- POWER and LIMIT lights flashing
Frequently asked questions
What are the GV90+4's ratings?
105 MBH input, 97 MBH DOE heating capacity, 84 MBH net AHRI and 91.2% AFUE.
Is the GV90+4 the same size as the GV90+3?
The cabinet length is the same at 30-3/4"; the +4 is heavier (353 lb shipping) and holds more water (4.7 gallons).
Can the GV90+ run a combi tankless coil?
Weil-McLain markets the GV90+ with its indirect-fired water heaters; the Series 2 manual notes the boilers are not available for millivolt systems.
Questions about the Weil-McLain GV90+4?
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 — GV90+ · accessed September 7, 2026
- GV90+ Series 2 Boiler Manual 550-143-010/0324 · 550-143-010/0324 · accessed September 7, 2026
Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.