Booster heaters are required on all high-temp dish machines. They assure that the final rinse temperature is within the correct range (180 – 195° F) to assure dish sanitization. If the booster is not included with your high-temp machine, you will need to get one with the appropriate temperature rise and make sure your incoming water temperature is correct. Booster heaters are like miniature water heaters, but unlike their full-size counterparts, the temperature cannot be manually adjusted. Each booster comes factory preset to deliver either a 40 or 70 degree rise to the incoming water temperature, which is then used to sanitize dishes during the final rinse phase. You will either have to indicate which rise you desire when selecting a booster. The temperature rise will also let you know what the incoming water temperature needs to be at. For a 40 degree rise, the incoming water needs to be at least 140 degrees, and for 70, it only needs to be 110° F.
Take note, it is the incoming water temperature that needs to be either 110 or 140° F. This does not mean that you should simply set your water heater to one temperature or the other and hope for the best. If the heater is far away from the machine, heat can be lost in the pipes as it travels to the washer. Pipe insulation can combat this, and save on utility costs, but it is always a good idea to check the water temperature at the machine to make sure it is hot enough. You can usually do this by pressing the manual-fill button on the washer and using an instant-read thermometer.