Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Comparison
Verdict in brief
The RTS/28HE-10 and RTS/28HE-14 are ten- and fourteen-section sizes of the 28HE RTS water boiler: 2,513 versus 3,567 MBH gross output, 2,185 versus 3,102 MBH net I=B=R water, and 249 versus 356 GPM at 20 °F ΔT. Both use 5" supply and return connections; the -14 adds about 1,000 MBH of gross output and roughly 3,300 lb of water working weight.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Smith RTS/28HE-10 | Smith RTS/28HE-14 |
|---|---|---|
| Gas burner capacity (as printed) | 3,033 MBH | 4,293 MBH |
| Gross output (as printed) | 2,513 MBH | 3,567 MBH |
| Net I=B=R water rating | 2,185 MBH | 3,102 MBH |
| Thermal efficiency — oil | 85.4 % | 85.7 % |
| Thermal efficiency — gas | 82.8 % | 83.1 % |
| Flow at 20 °F ΔT | 249 GPM | 356 GPM |
| Supply / return connection | 5" supply / 5" return | 5" supply / 5" return |
The -10 and -14 are both cast-iron sectional water boilers in the current 28HE RTS line. PDRTSHE-4 prints 2,513 MBH gross and 2,185 MBH net for the -10 (75 HP, 225.8 sq ft surface, 284.8 gal water) against 3,567 MBH gross and 3,102 MBH net for the -14 (106 HP, 322.2 sq ft, 392.4 gal). Burner capacity moves from 3,033 to 4,293 MBH gas, or 21.0 to 29.5 GPH oil.
Both sizes share 5" supply and return connections and the same standard RTS device, so the mechanical room planning turns on the larger boiler's footprint and water working weight — 9,169 lb for the -10 versus 12,467 lb for the -14. Flow at a 20 °F ΔT rises from 249 to 356 GPM, which has to be reflected in the pumps and near-boiler piping.
Printed efficiency is effectively unchanged across the two: 85.4% oil / 82.8% gas for the -10 and 85.7% / 83.1% for the -14. With the RTS standard on both, neither can be run as a condensing boiler, so a low-temperature distribution system still needs the mixing or bypass arrangement the installation manual describes.
Smith Cast Iron Boilers
The Smith RTS/28HE-10 is the 10-section 75 HP size of the 28HE RTS high-efficiency water boiler — 2513 MBH gross output, 2185 MBH net I=B=R water, 3033 MBH gas or 21 GPH oil burner capacity, with 5" supply and return connections.
Smith Cast Iron Boilers
The Smith RTS/28HE-14 is the 14-section 106 HP size of the 28HE RTS high-efficiency water boiler — 3567 MBH gross output, 3102 MBH net I=B=R water, 4293 MBH gas or 29.5 GPH oil burner capacity, with 5" supply and return connections.
PDRTSHE-4 prints 2,513 MBH gross / 2,185 MBH net for the RTS/28HE-10 and 3,567 MBH gross / 3,102 MBH net for the RTS/28HE-14.
Yes. Both sizes use 5" supply and 5" return connections per the PDRTSHE-4 water piping diagram; flow at 20 °F ΔT is 249 GPM on the -10 and 356 GPM on the -14.
The printed water working weight is 12,467 lb for the -14 against 9,169 lb for the -10 — a difference worth planning for in rigging and floor loading.
A consultation includes a heat-loss review so the size is right the first time.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.
Sources and verification
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.