Bosch Tankless Water Heaters

heating systems and gas supplies

Save on energy and space with a Bosch tankless water heater. These tankless water heaters never run out of hot water offering you constant comfort. They are cheap to operate and are without a doubt the most energy efficient water heater on the market. Designed to last 20 years, Bosch tankless water heaters are small, lightweight and will hang on the wall in your bathroom. We carry both the electric and gas tankless water heaters. Two of our most popular gas units include the GWF635 and the GWF425 listed below. If you go to, pick the model number that you are looking for and email it to us, we will get you a quote.

Powerful enough to supply two showers* running simultaneously. 
Our most powerful offering. Certainly the engineers at Bosch have outdone themselves — the beauty of this unit is in its simplicity. The 635 ES requires no special tools to install or maintain. And its compact size and sealed combustion enables installation in small spaces. A built-in power vent makes both vertical and horizontal venting possible while the electronic ignition maximizes energy efficiency. This unit yields enough power to supply two showers simultaneously and features an adjustable temperature control for improved comfort.
H 23½” x W 15¾” x D 8½”
Direct Vent Room Sealed Combustion
bosch  tankless water heater
Patented Bosch Hydro-Generated Ignition Technology.
The Bosch engineers have proven that water can indeed make fire. The pilot is ignited by a super-concentrated spark generated by a micro-turbine. The micro-turbine is activated by a request for hot water in the house. This energy efficient technology makes the 425 HN ideal for households looking to maximize energy savings.
H 29¾” x W 18¾” x D 8¾”
No Electricity Required
bosch  tankless water heater

Gas or Electric Tankless Water Heaters
There are two main types of tankless water heaters: electric and gas/propane water heaters. Choosing between them depends on how much you want to spend, whether you have access to gas/propane, how much electricity costs and where you live. Most people choose a gas water heater because the cost of gas is approximately one third that of electricity. Gas tankless systems also have wider applications because they produce hot water at higher flow rates. An electric tankless system is an appropriate choice only when gas is not an option and no space is available for a tank hot water heater.

Model GWF425 GWF635
BTU Input 117,000 175,000
Energy Factor 0.78 0.85
Effciency 82% 87%
Ignition Hydro-Generated Electronic
Capacity 4.25 gpm @ 45°F rise 45° F rise / 6.35 gpm
Weight 44 lbs 47 lbs

BTU Inputs- While a typical gas storage water heater has a gas input of 40,000 BTU/h, a gas tankless heater can use up to 175,000 BTU/h and may require larger gas lines and vents than conventional water heaters.
Energy Factor – describes the efficiency of both tank and tankless water heaters. The higher the energy factor, the more efficient the heater. Because tankless water heaters don’t have the losses associated with tanks, their energy factors are normally higher (although well-insulated, ultra-efficient tank heaters also have high energy factors). Energy factors for gas tankless water heaters range from around 0.69 to 0.84, compared with 0.55 for a conventional tank and 0.86 for an ultra-efficient tank heater.
Electronic Ignition – unless you use a large amount of water, an electric ignition is your best bet where water use is lower, i.e., in your own home.
Size or Capacity – choose the model closest to your flow rate and temperature rise needs. Choose the capacity during peak demand based on the number of users, the number of showers or bathtubs, whether or not you have a dishwasher, and how many hot water devices you expect to have open at one time.
Contact us today at one of our two locations listed below:

Tel: 416.492.6444

Tel: 416.534.2338 

heating systems and gas supplies