A. O. Smith · Conservationist Burkay (hot-water boilers)
A. O. Smith Burkay HW-520
The A. O. Smith Burkay HW-520 is a commercial gas-fired copper hot water boiler rated 520,000 BTU/h input and 416,000 BTU/h output, with 2" NPT water connections and a 1" NPT gas connection.
Key figures
- Max input
- 520,000 BTU/h natural and propane
- Max CSA output
- 416,000 BTU/h
- AFUE
- —
- Min input
- —
Input is gas energy consumed; output is heat delivered. Never size from input alone.
A. O. Smith Burkay HW-520 in practice
The HW-520 is a 520 BTU/h size of A. O. Smith's Conservationist Burkay commercial hot water boiler line, documented in spec sheet AOSDG25600 (© October 2024) and the HW user manual. It is a copper heat-exchanger, power-burner boiler for indoor commercial applications; water contacts only copper, brass and bronze, and the Burkay burner uses primary air injection at up to 72 orifices with secondary entrainment.
The spec sheet prints 2" NPT water inlet and outlet connections, a 1" NPT gas inlet and a 10" draft diverter outlet for this size, with an approximate shipping weight of 381 lb. Recovery is 2,521 GPH at 20 °F rise (natural gas). The boiler is ASME approved and hydrostatically tested for 160 psi, ships with an ASME 125 psi relief valve, and requires 120 V 60 Hz with a maximum inlet gas pressure of 14" WC. No efficiency percentage is printed on the spec sheet.
Best suited to
- Commercial hot-water supply loads sized to 520,000 BTU/h input
- Buildings that need a copper, non-ferrous-waterway boiler rather than a cast-iron sectional
- Indoor installations with a draft diverter and vertical venting
Applicability and support
- Model number
- HW-520
- Canadian availability
- unknown
- 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 A. O. Smith. Units are shown with every value; notes flag conflicting sources or missing figures.
| Specification | Value | Note |
|---|---|---|
| Input | ||
| Input rating | 520,000 BTU/h natural and propane | Printed in Table 3 of AOSDG25600. The HW-670 is printed as two rows: 660,000 BTU/h natural and 670,000 BTU/h propane. |
| Output | ||
| Output rating | 416,000 BTU/h | Printed in Table 2 of AOSDG25600 (natural and propane gas). |
| Domestic hot water | ||
| Recovery capacity (as printed) | 2,521 GPH at 20 °F rise (natural gas) | Printed in Table 3 of AOSDG25600; the table also prints recovery at 40/50/60/70/80 °F rise. |
| Venting and air | ||
| Draft diverter outlet diameter | 10 in | Printed in Table 1 of AOSDG25600. |
| Physical and connections | ||
| Water inlet / outlet | 2" NPT inlet / 2" NPT outlet | Printed in Table 1 of AOSDG25600. |
| Gas inlet | 1" NPT | Printed in Table 1 of AOSDG25600. |
| Approximate shipping weight | 381 lb | Printed in Table 1 of AOSDG25600. |
| Working pressure | 160 psi, ASME tested and certified | Spec sheet feature copy: ASME approved, hydrostatically tested and certified for 160 psi; ships with an ASME 125 psi relief valve. |
| Operating limits and other | ||
| Fuel | Natural gas or propane (LP) | Tables 2 and 3 of AOSDG25600 print natural and propane rows for every model. |
Manuals
Alerts documented for this model
Frequently asked questions
What is the input of the Burkay HW-520?
AOSDG25600 prints 520,000 BTU/h input for natural gas and propane, with 416,000 BTU/h output.
What connections does the HW-520 use?
Table 1 of the spec sheet prints 2" NPT water inlet and outlet connections, a 1" NPT gas inlet and a 10" draft diverter outlet.
Is the Burkay HW a boiler or a water heater?
A. O. Smith sells it as a commercial gas hot water boiler (copper heat exchanger, power burner, up to 670,000 BTU/h). The separate Burkay Genesis GWH models are circulating water heaters, not boilers.
Questions about the A. O. Smith Burkay HW-520?
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
- A. O. Smith — commercial water heating (hotwater.com) · accessed September 9, 2026
- A. O. Smith — Conservationist Burkay Commercial Gas Hot Water Boiler page · accessed September 9, 2026
- A. O. Smith — Burkay Hot Water Heating Boiler spec sheet AOSDG25600 (© October 2024) · AOSDG25600 · accessed September 9, 2026
- A. O. Smith — Gas Fired Commercial Copper Boilers HW 300/399/420/520/670 user manual · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.