Viessmann Vitocrossal 300 CU3A-199 Floor-Standing Condensing Boiler, 199 MBH

The Viessmann Vitocrossal 300 CU3A-199 is a heat-only gas condensing boiler for floor installation, built for big homes and light commercial spaces. It modulates from 43 to 199 MBH at 95% AFUE with a high-mass 18.8 gal water volume.

A stainless-steel Inox-Crossal heat exchanger and MatriX modulating dome burner yield a Net AHRI rating of 161 MBH, with efficiency up to 98% when return water is cool. Sound runs from 33 dB at minimum to 58 dB at maximum, and condensate output reaches 2.1 USG/h. The Vitotronic control offers outdoor reset, a start-up wizard and multi-circuit support. At 10,000 ft the boiler operates with an 18% de-rate.

Venting is direct, coaxial or two-pipe, using a 4 in. flue and 3 in. combustion air. Connections include 1¼ in. NPTM heating supply and return, ¾ in. NPTF gas and PRV, and a 1 in. NPTM boiler drain. It comes pre-wired and internally piped, set for natural gas and convertible to LP in the field.

Highlights

• 43-199 MBH input; Net AHRI 161 MBH

• 95% AFUE, up to 98% efficiency at low return temperatures

• High-mass 18.8 gal water volume

• Vitotronic outdoor-reset control with start-up wizard

• Field convertible from natural gas to LP

• ENERGY STAR; heat exchanger built to ASME Section IV and CSA B51

Specifications

In the box

• Vitotronic outdoor-reset control with outdoor sensor

• Installation fittings with 30 psig PRV

• Temperature and pressure gauge

Good to know

• Gas-fired appliance: it must be installed, vented and commissioned by a qualified installer in line with local codes and the manufacturer's installation manual.