WGO Oil Water Boiler Series 4

Features

Optimized System

Dedicated water-only oil boiler with cast iron sections – no tankless heater or cover plate

Easy Access

Quick open top and swing-away burner door with full chamber access increases visibility for inspection and servicing

Venting Options

Two flue outlets- rear and top – for complete venting flexibility

thoughtful Design

Recessed target wall design protects unit from flue brushes

Reliability

Includes factory-wired circulator (when specified), service switch and Weil-McLain exclusive captured elastomer seals for added reliability

Flexible Install

Available assembled or as a knockdown for installation areas with limited space

Locate a contractor Locate a Distributor Product Comparison Tool

B100 Certified Oil Boilers

Sustainable Heat for a Changing World

Weil-McLain SGO oil boilers are now B100 Certified, delivering reliable performance while supporting renewable heating. When used with approved Beckett and Carlin oil burners, our boilers are certified to operate with up to 100% biodiesel, giving homeowners and contractors a dependable, efficient solution that’s built for today and ready for the future.

Technical Specs

MODEL	BURNER INPUT RATING GPH	BURNER INPUT RATING MBH	HEATING CAPACITY (MBH)	NET RATINGS (MBH)	AFUE	DRAFT LOSS THROUGH BOILER (IN. W/C)	MIN. CHIMNEY SIZE RECTANGULAR (IN.)	MIN. CHIMNEY SIZE ROUND (IN.)	MIN. CHIMNEY SIZE HEIGHT (FT.)	APPROX. SHIPPING WEIGHT (LBS.)	ENERGY STAR®
WGO-2	0.7	98	86	75	86.4	0.1	8×8	6	15	540
WGO-2RD	0.7	98	86	75	87	0.01	8×8	6	15	540	YES
WGO-3R	0.8	112	98	85	86.2	0.02	8×8	6	15	595
WGO-3RD	0.8	112	98	85	87	0.01	8×8	6	15	595	YES
WGO-3D	0.95	133	115	100	86	0.02	8×8	6	15	595
WGO-4R	1	140	122	106	86.2	0.01	8×8	6	15	645
WGO-4RD	1	140	123	107	87	0.01	8×8	6	15	645	YES
WGO-4D	1.2	168	146	127	86	0.01	8×8	6	15	645
WGO-5R	1.2	168	147	128	86.1	0.015	8×8	7	15	760
WGO-5RD	1.2	168	148	129	87	0.015	8×8	7	15	760	YES
WGO-5D	1.45	203	176	153	86	0.015	8×8	7	15	760
WGO-6R	1.4	196	171	149	86.1	0.015	8×8	7	15	860
WGO-6RD	1.4	196	173	150	87	0.015	8×8	7	15	860	YES
WGO-6D	1.75	245	213	185	86	0.015	8×8	7	15	860
WGO-7R	1.6	224	196	170	86	0.015	8×8	8	15	930
WGO-7RD	1.6	224	197	171	87	0.015	8×8	8	15	930	YES
WGO-7D	2	280	244	212	86	0.015	8×8	8	15	930
WGO-8	2.3	322	266	231	–	0.025	8×12	8	20	1,030
WGO-9	2.55	357	295	257	–	0.03	8×12	8	20	1,135