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Triangle Tube · Prestige Solo

Triangle Tube Prestige Solo 399

The Prestige Solo 399 is the largest Prestige Solo: 72.5 to 399 MBH of input with 379 MBH DOE capacity, rated on the page at 95.1% thermal efficiency, in the 216 lb large cabinet — the workhorse of the Prestige Cascade kits. Discontinued with the November 3, 2025 cessation.

DiscontinuedHistorically in Canada
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Key figures

Max input
399 MBH
Max CSA output
—
AFUE
95.1 %
Min input
72.5 MBH
Natural gasPropaneHeating-onlyresidentialcommercial

Input is gas energy consumed; output is heat delivered. Never size from input alone.

Triangle Tube Prestige Solo 399 in practice

The Solo 399 tops the Prestige Solo line at 72.5 to 399 MBH of input with a 379 MBH DOE output and a 330 MBH net AHRI rating. Unlike the rest of the line the page does not rate it at 95% AFUE: the 399 column prints 95.1%** under a footnote identifying the figure as thermal efficiency, and the I&M manual's 399 table prints combustion efficiency of 94.1% alongside thermal efficiency of 95.1% with a notice that the 399's output rating is based on the efficiency.

Physically the 399 shares the 24 7/8"-wide large cabinet, 7.4-gallon water volume, 4" vent/air piping and 1 1/2" supply/return connections with the 299 at 216 lb. The Prestige Cascade line is built around it: two to five Solo 399 boilers combine for outputs of 500 to 2000 MBH (C800 through C2000 kits). Triangle Tube ceased operations November 3, 2025; this model is documented for the installed base.

Best suited to

  • Large plants whose heat-loss calculation approaches 399 MBH per boiler
  • Prestige Cascade arrangements from C800 (2 x 399) up to C2000 (5 x 399)
  • Commercial-style mechanical rooms with 4" venting and 1 1/2" piping runs

Applicability and support

Model number
Unknown
Canadian availability
historical
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.

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Specifications

Published specifications

Values as published by Triangle Tube. Units are shown with every value; notes flag conflicting sources or missing figures.

Triangle Tube Prestige Solo 399 specifications
SpecificationValueNote
Input
Heating input, minimum72.5 MBH
Heating input, maximum399 MBH
Output
DOE heating capacity379 MBHThe page lists 379 MBH under a footnote identifying 95.1% as thermal efficiency; the I&M manual prints combustion efficiency 94.1% and thermal efficiency 95.1% for the 399 and notes its output rating is based on the efficiency.
Net AHRI rating330 MBHPer the product-page spec table.
Efficiency
Efficiency (thermal)95.1 %The product-page 399 column reads 95.1%** with a footnote identifying it as thermal efficiency, not AFUE.
Venting and air
Vent/air diameter4"Per the product-page spec table.
Physical and connections
Water volume7.4 gal
Weight216 lb
Width24.875 in24 7/8" x 39 3/8" x 23 5/8" as printed.
Height39.375 in
Depth23.625 in
Supply/return connections1 1/2"
Gas connection1"
Operating limits and other
FuelNatural gas or propane
Turndown ratio5.5:1The page prints 5:5:1; 399 MBH divided by the 72.5 MBH minimum equals 5.5:1.
Maximum CH flow temperature185 °FPer the I&M manual.

Manuals

Alerts documented for this model

Services

Related parts & service

Frequently asked questions

Is the Solo 399 rated 95% or 95.1% AFUE?

The product page lists 95% AFUE for the Solo sizes through the 299, while the 399 column reads 95.1%** under a footnote identifying it as thermal efficiency. The I&M manual's 399 table prints combustion efficiency of 94.1% and thermal efficiency of 95.1%.

Which Prestige Cascade kits use the Solo 399?

The Prestige Cascade combines two to five Prestige 399 boilers for outputs of 500 to 2000 MBH, in kits C800 (2 x 399), C1200 (3 x 399), C1600 (4 x 399) and C2000 (5 x 399), per the cascade product page.

Questions about the Triangle Tube Prestige Solo 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.

Call 778-909-5731Request service

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Sources and verification

Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.

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