Viessmann CU3A-125 Vitocrossal 300 CU3A 125,000 BTU Gas Condensing Boiler

Description

From Plumbing Deals' product listing.

Elevate Your Heat With Viessmann CU3A-125 Vitocrossal 300 125 MBH Floor-Standing Condensing Boiler Looking for high-output comfort with lower fuel bills and fewer callbacks? The Vitocrossal 300 CU3A-125 is a floor-standing gas-fired condensing boiler that pairs Viessmann’s stainless Inox-Crossal heat exchanger with a self-calibrating MatriX dome burner for quiet, steady heat and 95% AFUE performance—ideal for radiator retrofits or multi-zone fin-tube systems. Brand: Viessmann MPN: CU3A-125 Type: Floor-Standing Gas-Fired Condensing (Heat-Only) Hydronic Boiler Size/Capacity: 25–125 MBH input; Net AHRI 101 MBH; 95% AFUE Material/Finish: Stainless-steel Inox-Crossal heat exchanger; MatriX dome modulating burner Performance: High-mass design with ~13.0 USG water content; sound rating ~55 dB max / 33 dB min; condensate up to ~1.2 USG/h Connections/Fit: 1¼" NPTM heating supply & return; ¾" NPTF gas; ¾" NPTF PRV; 3" (80 mm) flue & 3" combustion air; ¾" hose condensate Dimensions: 61.5" H (closed) / 67" H (open) × 26" W × 27" D Included: Vitotronic outdoor-reset control with outdoor sensor; 30 psig PRV & fittings; T&P gauge (field-installed on supply); factory pre-wired/piped internals; NG factory-set with LP conversion labels in literature set Certifications: ENERGY STAR; ANSI Z21.13/CSA 4.9; ASME Section IV / CSA B51 construction Warranty: Limited lifetime heat-exchanger warranty (residential)—see Viessmann warranty sheet Save Fuel With High Efficiency At 95% AFUE and up to 98% efficient under low-return temps, the CU3A condenses deeply to turn more of every therm into usable heat—cutting operating costs season after season. Everyday Performance You Can Feel A 25–125 MBH modulating input and high-mass water volume smooth out cycling and deliver quiet, even heat across changing loads—perfect for cast-iron radiators or mixed high-temp zones. Built To Last The Inox-Crossal stainless heat exchanger is constructed to ASME Section IV/CSA B51 and designed for a self-cleaning condensate “sheen,” helping maintain efficiency and resist corrosion over time. Installer-Friendly Flexibility Direct-vent coaxial or two-pipe options with long allowable runs (layout-dependent, up to ~198 ft per Viessmann guidelines) make venting straightforward. Standard 1¼" supply/return and ¾" gas keep piping simple. Smart Controls & Compatibility The integrated Vitotronic control with outdoor reset, zone-circuit capability, and start-up wizard speeds commissioning. High-altitude operation is supported up to 10,000 ft (electronic adjustment; de-rate applies). Fits Your Space A compact footprint (26" × 27") and zero-clearance to combustibles rating allow closet or alcove installs while keeping full front/rear service access.