HTP · Elite Premier (discontinued)
HTP EP-399
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.
Key figures
- Max input
- 399 MBH
- Max CSA output
- —
- AFUE
- 96.5 %
- Min input
- 40 MBH
Input is gas energy consumed; output is heat delivered. Never size from input alone.
HTP EP-399 in practice
The EP-399 is one of the seven Elite Premier models HTP's retired product page lists from EP-80 to EP-399. The official page table prints 40,000 to 399,000 BTU/hr input at 96.5% AFUE, and LP-550 Table 4 adds 385 MBH heating capacity, a 256 lb shipping weight, 3.7 gal of boiler water content and a 14.5" x 36" x 31.75" (W x H x D) cabinet. The line uses a 316L stainless steel water tube heat exchanger and the 928 SIT control.
The retired page describes the line as a low-mass boiler with 'a 10 to 1 turndown ratio', 96% efficiency copy, a 12 year limited warranty, floor or wall mounting (mount sold separately) and venting in PVC pipe up to 200 combined feet. LP-550 Table 4 prints 160 psi heat-exchanger MAWP with a 30 psi relief valve, the 1-1/2" NPTF CH supply/return connection and the 1" NPTF gas inlet; the LP-558 specification sheet gives the connection sizes for the whole line (1" for 80-220, 1-1/4" for 299/301, 1-1/2" for 399).
The Elite Premier is retired history: HTP's official discontinued-products index lists the 'Elite Premier Boiler' and the Elite Premier documents page states verbatim 'This model has been discontinued, please refer to the below documentation for support.' Boilers.ca records it with productStatus 'discontinued' and canadianStatus 'unknown' — no official Canadian sales statement was found. Owners should have the unit serviced by a licensed contractor against LP-550.
Best suited to
- Identifying a retired Elite Premier unit already installed in a home
- Sourcing the official LP-550/LP-549/LP-558 documentation for an existing unit
- Replacement planning where the existing boiler's input and capacity are known
Applicability and support
- Model number
- EP-399
- Canadian availability
- unknown
- Production status
- discontinued
- 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 HTP. Units are shown with every value; notes flag conflicting sources or missing figures.
| Specification | Value | Note |
|---|---|---|
| Input | ||
| Input rate, minimum | 40 MBH | 40,000 BTU/hr, as printed on the official Elite Premier model table. |
| Input rate, maximum | 399 MBH | 399,000 BTU/hr, as printed on the official Elite Premier model table. |
| Output | ||
| Heating capacity | 385 MBH | As printed in LP-550 Table 4 (Technical Specifications). |
| Efficiency | ||
| AFUE (as printed) | 96.5 % | Printed as 96.5* on the retired page with N/A in the Energy Guides column. The LP-558 specification sheet states the 399 connection size as 1-1/2"; LP-550 Table 4 prints 1" NPTF in the 399 cell — recorded from LP-558 with the manual print noted. |
| Venting and air | ||
| Venting | 4" (200 ft) or 6" (275 ft), combined equivalent feet | Category IV sealed-combustion direct vent, power vent; PVC, CPVC, polypropylene or stainless steel per LP-550 Table 4. |
| Physical and connections | ||
| Shipping weight | 256 lb | As printed in LP-550 Table 4. The 299 and 301 sizes share the printed 211 lb row. |
| Boiler water content | 3.7 gal | As printed in LP-550 Table 4; the 299 and 301 sizes share the printed 3.1 gal row. |
| Dimensions (W x H x D) | 14.5" x 36" x 31.75" | As printed in LP-550 Table 4; the cabinet width prints as 14.5 in across the line. |
| Gas supply connection | 1" NPTF | Per LP-558: 3/4" for the 80/110/150, 1" for the 220/299/301/399; LP-550 Table 4 prints 3/4" NPTF and 1" NPTF in the same split. |
| Water pressure | Heat-exchanger MAWP 160 psi; pressure-relief valve 30 psi | As printed in LP-550 Table 4 (160 psi working pressure in LP-558). |
| Heat exchanger | 316L stainless steel water tube | LP-550 Table 4 materials row; page copy describes a low-mass 316L stainless steel heat exchanger. |
| Operating limits and other | ||
| CH supply/return connection | 1-1/2" NPTF | Connection sizes per the LP-558 specification sheet (1" for 80-220, 1-1/4" for 299/301, 1-1/2" for 399). LP-550 Table 4 prints 1" NPTF in the 399 cell. |
| Control | 928 SIT control with LCD display and LED indicators | Outdoor reset, DHW indirect priority, cascade (LP-549 submittal prints up to eight boilers; LP-558 spec text says sixteen), 0-10V BMS input. |
| Turndown | 10:1 | Page copy: '96% efficient with a 10 to 1 turndown ratio'; the internal-shutter mixer increases turndown to 10:1. |
| Warranty | 12-year limited out of the box, no registration required | Retired product page: 'backed by a limited 12 year warranty out of the box! No registration is required.' |
Manuals
- HTP Elite Premier Heating Boiler Installation and Operation Manual — LP-550 Revision Date 3.4.22LP-550 (3.4.22) · 2022-03-04
- HTP Elite Premier Heating Boiler Submittal Sheet — LP-549 Rev. 7.14.20LP-549 (7.14.20) · 2020-07-14
- HTP Elite Premier Heating Boiler Specification Sheet — LP-558LP-558
Alerts documented for this model
Frequently asked questions
What is the input range of the EP-399?
The retired official table prints 40,000 to 399,000 BTU/hr with a 385 MBH heating capacity and 96.5% printed AFUE.
Is the Elite Premier still sold?
No. HTP's discontinued-products index lists the Elite Premier Boiler and the documents page carries the official wording 'This model has been discontinued, please refer to the below documentation for support.'
Where can I find the manual for an EP-399?
HTP keeps LP-550 (installation and operation, Revision Date 3.4.22), LP-549 (submittal) and LP-558 (specification) live on htproducts.com; the links are recorded on this model record.
Questions about the HTP EP-399?
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
- HTP — Elite Premier Low Mass Boiler (retired page, model table) · accessed September 9, 2026
- HTP — Elite Premier documents (official discontinued wording) · accessed September 9, 2026
- Elite Premier Installation and Operation Manual, LP-550 (3.4.22) · accessed September 9, 2026
- Elite Premier Submittal Sheet, LP-549 (7.14.20) · accessed September 9, 2026
- HTP — Discontinued Products index · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.