Are Bosch and Buderus the same company?

Yes. Both are Bosch Thermotechnology brands. In the US, Bosch is the gas condensing line and Buderus is mostly cast iron oil boilers.

Can a Bosch Greenstar run on propane?

Yes. Greenstar boilers are rated for natural gas or propane, and the floor-standing models include a propane conversion kit.

How much hot water does a Bosch combi boiler make?

It depends on the model. A Greenstar Combi 151 delivers 4.0 GPM at a 72°F rise, and a Singular 5200 delivers 7.7 GPM at a 45°F rise.

Do I have to register my Bosch boiler?

You should. Registering within 90 days of installation gets you up to five years of parts and labor coverage at Bosch's approved rates.

Does a Bosch boiler need a chimney?

No. Greenstar boilers vent with 2 or 3 inch PVC, CPVC or polypropylene pipe, usually out a side wall.

Bosch Boiler Installation and Repair

Boiler Brand

About Bosch Boilers

We install, repair and service Bosch boilers across Long Island, and we stock the common parts for Greenstar and Singular models. Factory-trained technicians take no-heat calls 24/7, and every new install starts with a free estimate.

Bosch Thermotechnology Corp., part of the Bosch Home Comfort Group, sells Bosch boilers in the US. The same company supports Buderus, the older German brand Bosch owns. In the home boiler lineup, Bosch is the gas condensing name.

The core line is Greenstar. Each one uses an aluminum-silicon alloy heat exchanger and a fully modulating fan that speeds up or slows down to match the heat your home needs. The Singular combi boilers use stainless steel heat exchangers and are built for homes that want more hot water from one box.

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All Models Serviced

Model Lineup

Bosch Boiler Models We Install and Service

All figures are Bosch ratings. Heat-only floor-standing Greenstar models carry an indirect tank sensor, so pairing one with a storage tank is simple.

Model	Type	Key Ratings	Good For
Greenstar 79 / 100	Heat-only, wall or floor	95% AFUE; input 24.6 to 79.2 / 24.6 to 100 MBH	Smaller homes, often with an indirect tank
Greenstar 131 / 151	Heat-only, wall or floor	95% AFUE; input 36 to 131.9 / 36 to 151.6 MBH	Larger homes and more zones
Greenstar Combi 100 / 131 / 151	Combi, wall or floor	95% AFUE; hot water 2.65 / 3.2 / 4.0 GPM at a 72°F rise	Heat plus on-demand hot water
Singular 4000 / 5200	Combi, wall-hung	95.0% AFUE; heat up to 80,000 / 140,000 BTU/h	Homes with two or more bathrooms

Long Island Homes

Bosch Boilers for Long Island Homes

Many Long Island homes have natural gas, and homes past the gas mains often use propane. Greenstar and Singular boilers handle both, and the floor-standing Greenstar FS ships with a propane conversion kit in the box.

Because these boilers condense, they vent in plastic pipe through a side wall instead of a chimney. That's handy when an old chimney needs a liner. It also means we need somewhere to drain condensate, which in a finished basement can mean a small pump.

If you heat with oil today, a Bosch boiler means converting to gas first. Want to stay on oil? A cast iron Buderus oil boiler is the Bosch-family option.

Warranty

Bosch Boiler Warranty

Bosch's current warranty for boilers with aluminum heat exchangers, sold on or after July 1, 2024 for one- or two-family homes, breaks down like this:

On top of the manufacturer's coverage, Domino backs every installation with a 1-year labor warranty.

Registered within 90 days: Bosch repairs or replaces defective parts, with labor at its approved rates, for up to five years.
Heat exchanger: covered against leaks for ten years. After year five, labor isn't included.
Year 11 on: the heat exchanger is pro-rated. You pay 20% of list in year 11, rising to 75% from year 15.
Not registered: first-year labor isn't included. Parts Bosch doesn't make carry their own maker's warranty plus one year from Bosch.
Singular combi boilers carry a 10-year heat exchanger and 5-year parts warranty for homes.
Skipping the water quality rules in the install manual voids coverage, so we treat and test the boiler water at start-up.

Compare Brands

Bosch vs Buderus Boilers

Same parent, different jobs. Bosch and Buderus boilers are both made and backed by Bosch Thermotechnology, and they even share one aluminum heat exchanger warranty.

The difference is what each name covers today. Bosch-brand boilers are gas condensing: Greenstar and Singular, 95% AFUE, vented in plastic. Buderus-brand home boilers in the US are cast iron oil boilers like the G115WS and G215, rated 86% to 87% AFUE. Older Buderus gas condensers, such as the GB142, are discontinued. Pick by fuel first, then compare models on our boiler brands page.

Repair & Service

Bosch Boiler Repair and Service

Bosch changed the Greenstar relief valve pipe from 18 mm to 22 mm, and the new parts aren't backward compatible with older units. We match every part to your serial number, and we stock the common ones: electrodes, condensate traps, sensors, pumps and relief valves.

A yearly tune-up covers a combustion test, condensate trap cleaning, a heat exchanger inspection and a water quality check. Bosch says Greenstar boilers need scheduled maintenance to run safely and efficiently.

Pressure gauge reading low: a slow leak or a tired expansion tank. Condensing boilers lock out to protect themselves.
Lukewarm showers on a combi: scale in the plate heat exchanger that makes domestic hot water.
Gurgling or lockout after a cold snap: a blocked condensate trap or a frozen condensate line.
Ignition faults: a worn electrode, gas pressure under the 3.5 inch water column minimum on the Greenstar FS, or a blocked vent.
Banging or kettling: poor flow from a weak pump or sludge in the system.

Installation

Bosch Boiler Installation and Replacement

Price depends on boiler size, combi or heat-only, vent length, gas line upgrades, condensate handling and how much piping changes. Call for a quote, or see all our boiler service options.

Free in-home estimate and heat loss calculation, so the boiler fits the house.
Choose heat-only with an indirect tank, or a combi.
Plan the sidewall vent run and the condensate drain.
Remove the old boiler, mount the Bosch and pipe it, with a low-loss header where the install calls for one.
Fill with treated water, commission and test, then register the boiler for you within 90 days.

Bosch Boiler Installation and Repair on Long Island