Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
Boilers.ca is a brand of ROMA Heating & Cooling · Licensed gas contractor LGA0202903
Comparison
Verdict in brief
The EP-399 tops the Elite Premier line at 40,000-399,000 BTU/hr with 385 MBH heating capacity, a 1-1/2" CH connection, a 14.5 x 36 x 31.75 in cabinet and 256 lb shipping weight. It prints 96.5* efficiency against the EP-301's 96.1*, but its minimum fire is 10,000 BTU/hr higher.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | HTP EP-301 | HTP EP-399 |
|---|---|---|
| Input rate, minimum | 30 MBH | 40 MBH |
| Input rate, maximum | 301 MBH | 399 MBH |
| AFUE (as printed) | 96.1 % | 96.5 % |
| Heating capacity | 289 MBH | 385 MBH |
| Shipping weight | 211 lb | 256 lb |
| Boiler water content | 3.1 gal | 3.7 gal |
| Dimensions (W x H x D) | 14.5" x 36.5" x 24.75" | 14.5" x 36" x 31.75" |
| CH supply/return connection | 1-1/4" NPTF | 1-1/2" NPTF |
| Gas supply connection | 1" NPTF | 1" NPTF |
| Venting | 4" (200 ft) or 6" (275 ft), combined equivalent feet | 4" (200 ft) or 6" (275 ft), combined equivalent feet |
Input runs 30,000-301,000 BTU/hr on the EP-301 and 40,000-399,000 on the EP-399; LP-550 Table 4 prints 289 vs 385 MBH heating capacity and the retired page prints 96.1* vs 96.5* efficiency.
The EP-399 moves to a 1-1/2" NPTF CH connection per LP-558 (LP-550 Table 4 prints 1" NPTF in the 399 cell), deepens the cabinet to 31.75 in and adds 45 lb (256 vs 211 lb) with 3.7 vs 3.1 gal water content.
Both share the 1" NPTF gas inlet, 4"/6" venting and 160 PSI MAWP; the EP-399's 40,000 BTU/hr minimum fire is the trade-off for the top-of-line capacity.
HTP
The HTP EP-301 is the 301 MBH class model of the retired Elite Premier low-mass condensing boiler line: 30,000 to 301,000 BTU/hr input, 96.1% printed AFUE, 289 MBH heating capacity and a 211 lb shipping weight, recorded from the official retired Elite Premier table.
HTP
The HTP EP-399 is the 399 MBH class model of the retired Elite Premier low-mass condensing boiler line: 40,000 to 399,000 BTU/hr input, 96.5% printed AFUE, 385 MBH heating capacity and a 256 lb shipping weight, recorded from the official retired Elite Premier table.
40,000-399,000 BTU/hr with 385 MBH heating capacity and 96.5* printed efficiency.
LP-558 prints 1-1/2" for the 399; LP-550 Table 4 prints 1" NPTF in the 399 cell, so Boilers.ca records the specification-sheet value and flags the manual print.
LP-550 Table 4 prints 256 lb against 211 lb for the EP-301.
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.