AERCO Benchmark 4000
The AERCO Benchmark 4000 (BMK 4000) is a condensing gas-fired firetube commercial boiler rated 4000 MBH maximum input and a 3480–3840 MBH output range in AERCO's published ratings table, at 94.1% thermal efficiency (87%–98% range), with 15:1 (7%) turndown and a 2200 lb dry weight.
Key figures
- Max input
- 4,000 MBH
- Max CSA output
- 3,840 MBH
- AFUE
- —
- Min input
- 267 MBH
Input is gas energy consumed; output is heat delivered. Never size from input alone.
AERCO Benchmark 4000 in practice
AERCO's Benchmark 750–6000 with Edge Controller TDS prints the BMK 4000 at 267 MBH minimum input, 4000 MBH maximum input and a 3480–3840 MBH output range (Max Output depends on application — see efficiency curves). Thermal efficiency at 80º–180ºF is 94.1% and the efficiency range for every row is 87%–98%.
The specifications table lists 15:1 (7%) turndown, a 3" NPT gas connection, a 6" flanged water connection, 2200 lb dry weight (2350 lb shipping) and dimensions of 34" wide × 63.5" deep × 78.2" high. The unit is ASME Section IV and runs on natural gas, propane or dual fuel.
The Benchmark uses a 439 stainless-steel firetube heat exchanger, an integrated O2 monitoring system with TComp air-temperature compensation, up to 20:1 turndown depending on capacity, on-board Boiler Sequencing Technology for plants of 2–16 boilers, and the Edge controller with BACnet/Modbus communications. AERCO's page copy notes NOx capability of 9 ppm or less at all firing rates depending on capacity. No official Canadian-sales statement was found, so canadianStatus stays unknown.
Best suited to
- Commercial plants documenting an installed Benchmark 4000 against AERCO's TDS
- Hydronic systems in the 4000 MBH input class
- Modular plants using Boiler Sequencing Technology across 2–16 units
Applicability and support
- Model number
- BMK 4000
- Canadian availability
- unknown
- 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 AERCO (Watts). Units are shown with every value; notes flag conflicting sources or missing figures.
| Specification | Value | Note |
|---|---|---|
| Input | ||
| Min. input | 267 MBH | Min Input MBH per the TDS ratings table. |
| Max. input | 4,000 MBH | Max Input MBH per the TDS ratings table. |
| Output | ||
| Max. output | 3,840 MBH | TDS prints Max Output as 3480–3840 MBH depending on application (see efficiency curves); the upper figure is recorded here. |
| Efficiency | ||
| Thermal efficiency (80–180°F) | 94.1 % | Thermal Efficiency 80º to 180ºF per the TDS ratings table. |
| Efficiency range | 87–98 % | Efficiency range printed for every BMK row in the TDS ratings table. |
| Physical and connections | ||
| Gas connection (NPT) | 3" | Gas Connections (NPT) per the TDS specifications table. |
| Water connection (flanged) | 6" | Water Connect. (Flanged) per the TDS specifications table. |
| Weight, dry | 2,200 lb | Weight (dry) per the TDS specifications table. |
| Shipping weight | 2,350 lb | Shipping Weight per the TDS specifications table. |
| Width (A) | 34 in | Dimension A in the TDS dimensions table. |
| Depth (B) | 63.5 in | Dimension B in the TDS dimensions table. |
| Height (C) | 78.2 in | Dimension C in the TDS dimensions table. |
| Operating limits and other | ||
| Turndown ratio | 15:1 (7%) | As printed in the TDS specifications table. |
| Boiler category | ASME Sect. IV | Boiler Category row of the TDS specifications table. |
| NOx emissions | capable of 9 ppm or less at all firing rates depending on capacity | TDS feature list; the table notes BMK 5000/6000 at standard gas pressure (>14" W.C.) can achieve 9 ppm NOx. |
Manuals
Alerts documented for this model
- AIRFLOW FAULT DURING PURGE
- AIRFLOW FAULT DURING IGN
- AIRFLOW FAULT DURING RUN
- DELAYED INTERLOCK OPEN
- DIRECT DRIVE SIGNAL FAULT
- FFWD TEMP SENSOR FAULT
- FLAME LOSS DURING IGN
- FLAME LOSS DURING RUN
- HEAT DEMAND FAILURE
- HIGH EXHAUST TEMPERATURE
- GAS PRESSURE FAULT
- HIGH WATER TEMPERATURE
- HIGH WATER TEMP SWITCH OPEN
- IGN BOARD COMM FAULT
- IGN SWTCH CLOSED DURING PURGE
- IGN SWTCH OPEN DURING IGNITION
- INTERLOCK OPEN
- LINE VOLTAGE OUT OF PHASE
- LOW WATER LEVEL
- NETWORK COMM FAULT
- O2 % OUT OF RANGE
- OUTDOOR TEMP SENSOR FAULT
- OUTLET TEMP SENSOR FAULT
- PRG SWTCH CLOSED DURING IGNITION
- PRG SWTCH OPEN DURING PURGE
- REMOTE SETPT SIGNAL FAULT
- RESIDUAL FLAME
- SSOV SWITCH OPEN
- SSOV FAULT DURING PURGE
- SSOV FAULT DURING IGN
- SSOV FAULT DURING RUN
- SSOV RELAY FAILURE
- STEPPER MOTOR FAILURE
Frequently asked questions
What are the Benchmark 4000 ratings?
AERCO's TDS prints 267 MBH minimum input, 4000 MBH maximum input, a 3480–3840 MBH output range and 94.1% thermal efficiency at 80º–180ºF, with 15:1 (7%) turndown.
What fuel does the Benchmark 4000 use?
The TDS specifications table lists natural gas, propane or dual fuel, with a 3" NPT gas connection.
Is the Benchmark 4000 condensing?
Yes — AERCO lists the Benchmark as a condensing boiler with a 439 stainless-steel firetube heat exchanger and an 87%–98% efficiency range.
Questions about the AERCO Benchmark 4000?
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
- AERCO Benchmark 750–6000 with Edge Controller Technical Data Sheet (PDF) · accessed September 9, 2026
- AERCO Benchmark 750–6000 Technical Data Sheet (PDF) · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.