Burnham · Series
Burnham K2
The K2 is U.S. Boiler Company's current K2 family of condensing boilers under the Burnham brand — the NEW K2 Firetube (six wall-hung sizes with a 155 MBH combi), the K2 Combi and the original K2 Watertube — all current-generation marketing pages on usboiler.net, NOT retired.
Series facts
- Type
- condensing
- Efficiency
- 95% AFUE
- Fuel
- The official K2 pages print natural-gas wording only (low-NOx, SCAQMD Rule 1146.2 on the K2 Combi); no LP/propane statement was captured for the K2 family, so propane is not recorded.
- Venting
- Direct vent condensing boiler with universal boiler vent connections for polypropylene, CPVC/PVC and flexible stainless steel (stainless steel listed on the K2 Watertube page); two-pipe venting per the K2 installation literature.
- Models documented
- 0
- Warranty
- Published terms
'95% AFUE — high efficiency' printed on the K2 Firetube page ('95% AFUE … 5:1 modulation'), '95% AFUE with 10:1 turndown' on the K2 Combi page, and 'The K2 is 95% AFUE for all sizes!' with 10:1 turndown on the K2 Watertube page (Sage2.3 control).
About the K2
Batch8 research settles the 'is K2 retired?' question: NO. All three K2 pages on usboiler.net are live, current-generation marketing pages (fetched 2026-09-09). The K2 Firetube page headlines 'The NEW K2 Firetube condensing boiler is an addition to the K2 high-efficiency series. Joining the K2 Watertube boiler, the K2 Firetube features a stainless steel vertical firetube heat exchanger and is available in six sizes. All models can be wall-hung and feature 5:1 modulation', with 'Six wall hung models; 85, 110, 155, 205, 270 MBH (combi version available for 155 MBH)' and the Sage2.2 boiler control.
The K2 Combi page prints 'K2 Combi — 95% AFUE with 10:1 turndown', a flat plate heat exchanger for domestic hot water, the factory pre-set Sage2.3 control system with touch screen diagnostic display, low NOx meeting SCAQMD Rule 1146.2, outdoor reset and sensor, and a FREE 5-year parts warranty. The K2 Watertube page (sitemap slug k2-high-efficiency-condensing-boiler; page title 'K2 High-Effiency Condensing Boiler' as printed) documents the original K2 watertube line — 'Five wall hung models; 80, 100, 120, 150, 180 MBH' on Sage2.3 at 95% AFUE for all sizes — and links the K2 Product Data Sheet.
Boilers.ca documents the K2 family at hub level because batch8 captured no per-model spec tables for it (the pages print sizes only — no ratings rows to transcribe); sizes and features are recorded in the copy above and in the highlights. Note the product-sitemap URL collisions flagged in research: URLs resolving from k2-firetube '…html-2/-3/-4' belong to the Carefree (electric), CHG and Freedom legacy stubs, not to K2 products. No official Canadian-sales statement exists on the official pages, so canadianStatus stays 'unknown'.
Highlights
- NOT retired: K2 Firetube ('NEW'), K2 Combi and K2 Watertube pages all carry live current-generation copy (fetched 2026-09-09)
- K2 Firetube: six wall-hung models, 85, 110, 155, 205, 270 MBH (combi version available for 155 MBH); 5:1 modulation; Sage2.2 control; stainless steel vertical firetube heat exchanger
- K2 Combi: 95% AFUE with 10:1 turndown; flat plate DHW heat exchanger; factory pre-set Sage2.3; FREE 5-year parts warranty
- K2 Watertube: five wall-hung models, 80, 100, 120, 150, 180 MBH; 95% AFUE for all sizes; 10:1 turndown with Sage2.3; K2 Product Data Sheet linked
- Universal vent connections for polypropylene, CPVC/PVC and flexible stainless steel; low NOx (SCAQMD Rule 1146.2 on the combi)
- No model-level spec rows published (no ratings table captured in batch8); no Canadian availability wording found
FREE 5-year parts warranty included, per the official K2 Combi and K2 Watertube pages.
Models
K2 models
One canonical page per model with input, output and efficiency kept separate.
Error codes and alerts
K2 alerts
No alerts documented for this series yet.
Manuals
Official documents
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.
Services for Burnham boilers
Frequently asked questions
Is the K2 retired?
No. All three K2 pages are live current-generation marketing pages on usboiler.net: the 'NEW' K2 Firetube, the K2 Combi and the original K2 Watertube line page. The nav label 'Boilers not of Current Manufacture' does not apply to the K2 family.
Which K2 sizes are printed on the official pages?
K2 Firetube: 85, 110, 155, 205, 270 MBH (wall-hung, with a combi version available for the 155). K2 Watertube: 80, 100, 120, 150, 180 MBH. Batch8 captured no per-model ratings table for either, so Boilers.ca keeps the family at hub level.
Does the K2 use Sage controls?
Yes — the K2 Firetube prints the Sage2.2 boiler control and the K2 Combi and K2 Watertube print the factory pre-set Sage2.3 control system with a touch screen diagnostic display.
Talk to a boiler technician
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
- U.S. Boiler Company — K2 Firetube product page ('NEW' current-generation copy) · accessed September 9, 2026
- U.S. Boiler Company — K2 Combi High Efficiency Condensing Boiler product page · accessed September 9, 2026
- U.S. Boiler Company — K2 High-Effiency Condensing Boiler product page (original K2 watertube; K2 Product Data Sheet linked) · accessed September 9, 2026
- K2 — Product Data Sheet (PDF) · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.