The Aquastar 125bo And 125b Heater Models
The Bosch Aquastar 125 BO gas tankless water heater is a great supplier of hot water for one major appliance. The biggest advantage it has is that it is designed to be installed outdoors, so no venting is needed. It also has freezing protection. The lowest temperature it can withstand is 5 degrees Fahrenheit. The difference between the 125BO and 125B is that the 125BO is designed to be installed outdoors. You can get this model for natural gas or propane.
The energy factor for this model is 0.69 for natural gas and 0.79 for propane. Its average efficiency reaches 80%. The minimum flow rate for the 125BO is 0.5 gallons per minute. The temperature rise achieved by this model and the according flow rates are: The highest temperature rise 90°F is reached at the flow rate of 2.1 gallons per minute.
The temperature rise of 75°F is achieved at a flow rate of 2 gallons per minute. The water can reach a temperature rise of 65°F at a flow rate of 2.8 gallons per minute. At a flow rate of 3.3 gallons per minute, the temperature rise achieved is 55°F. And the lowest temperature rise, 45°F, is achieved at the flow rate of 4.2 gallons per minute.
The installation process of this model is much easier then it is for the other Aquastar models just because this is an outdoor model. No venting system is required, and that makes the installation way easier. More details that you might need for the installation are: The gas connection type is 3/4″ NPT and for the water it’s 1/2″ NPT. The 125 BO model is 36 3/4″ high, 18 1/4″ wide and the depth is 10 1/2″. It is one of the heaviest models, it has 57 lbs. The water pressure for this model shouldn’t be higher than 150 PSI and not lower than 30 PSI. The minimum natural gas pressure shouldn’t be lower than 7″ W.C. and the propane pressure not lower than 11″ W.C.
The warranty that is offered for the 125BO model is excellent. You get a 12 year warranty on the heat exchanger if you use the tankless water heater only for a single family home. In any other conditions you get only a 2 year warranty for the heat exchanger. The warranty for all other parts is for 2 years. In our opinion, this is the easiest gas model that you can install, because no venting is required. So if you need a tankless water heater for one major appliance and you want it to be an outdoor model, the 125BO is a good choice!