HANDYMAN Q & A : Water Tank Heat Set for Over 140 Wasteful

QUESTION: Most hot water tanks have a dial for water temperatures at their bottom. They read hot, warm and normal. What would be the minimum temperature and the next temperature and then the hot temperature? I have heard of a code in most places that the minimum temperatures should be 120 degrees and the maximum 140 degrees.

ANSWER: Not all water heater manufacturers use the same names for the thermostat settings. Nevertheless, the settings are basically hot, medium and warm. On some water heaters there is also a vacation setting. According to the manufacturers, the respective temperatures are 160 degrees Fahrenheit, 140 F, 120 F and 60 F. These temperatures are not too precise as there can be a difference of 10 degrees or more between the dial setting and the water temperature.

The thermostat for a tank type water heater is at the lower portion of the tank. Since hot water rises, the temperature of the water at the top of the tank (where the hot water outlet pipe is located) will be higher than the water surrounding the thermostat.

You must also consider that as the hot water flows through the distribution pipes, some heat will be lost. Consequently, the water temperature discharging from the various faucets will be lower than the water temperature at the top of the heater tank.

For the most part, a thermostat setting that produces a water temperature of 140 F will be adequate for household appliances such as clothes washers and dishwashers. However, when dishes are to be washed by hand or when bathing, a water temperature of 120 F is probably too hot for most people and needs to be tempered with a bit of cold water.

Setting the thermostat so its temperature exceeds 140 F is wasteful of energy and will shorten the life of the water heater. Water temperature in excess of 160 F is a potential hazard because of the possibility of being scalded while showering if the shower’s mixing valve is faulty.

Glass-Flipping Washer May Need a New Arm

Q: My Maytag dishwasher has a curious problem. When the machine was about 3 years old, the water pump failed and I replaced it with another Maytag pump. The dishwasher then worked perfectly for about six months. Then the force of the water began flipping over the drinking glasses on the bottom rack, breaking nearly two dozen of them. Both the upper and lower spray arms are spinning freely and the water outlet holes are not clogged. Any clues?

A: This problem may be with the lower wash arm made of polypropylene plastic. When the wash arm has developed a crack or split, all the water under pressure that comes into the arm doesn’t pass through the holes in the arm as it should. The water finds its way to the crack, enlarges it, and squirts out in all directions.

This causes strange things to happen inside the dishwasher, including flipping glasses. We suggest you remove the lower wash arm and inspect it carefully. Look for a hairline crack, particularly along the top of the spray arm.