Safest hot water heater temperature setting 120 degrees
chambleemama
15 years ago
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sparky823
15 years agosherwoodva
15 years agoRelated Discussions
Hot water heater setting & dishwasher?
Comments (8)The temperature setting of your water heater is very closely regulated by the plumbing codes. If all bathtubs and showers are equiped with "Anti-scald" mixing valves both the International Residential Code and the Uniform Plumbing Code will permit the water heater and potable water distribution temperature to be 140degF maximum. If you do not have anti-scald mixing valves the maximum allowable temperature is 125degF. (some local codes limit it to 120degF). Most water heater gas controls have an index mark on the thermostat dial to indicate 125degF. It may be a Dot, longer line or possibly a different colored line at the 120DegF index. Keep in mind that the setting on the water heater is only a theoretical setting and it may vary slightly from one installation to another depending upon such conditions as the temperature of the incoming water, fuel gas pressure, etc. The best way to check the temperature is to actually measure the water temperature with a thermometer of known accuracy at the closest faucett to the water heater. Most residential dishwashers have a built in heating element that is primarily used for the drying cycle, however that element is also used as a booster heater to heat the water in the sump and thereby insure the water is at the required temperature for the dishwasher. Some dishwashers have an "Energy Saver" switch which disables the internal heating element during the wash cycle. If you are having problems with the dishwasher that are attributed to water that is not high enough the first step is to make sure the "Energy Saver" switch is turned off. If your dishwasher requires a water input temperature greater than the code allowed potable water distribution temperatures the solution is to install a small "On Demand" water heater or a 6gal tank type to supply water directly to the dishwasher....See MoreWater heater temperature?
Comments (1)Code maximum is 120degF unless all tubs and showers are equipped with anti-scald valves, however if you have non-chlorinated water you should keep the water heater at 120degF to prevent the growth of bacteria in the vessel....See MoreIndirect water heater running out of hot water.
Comments (4)I had a conversation with a local pro, and he believes adding a mixing valve and turning the aquastat up from 100* to something like 140* will do wonders. He said it's normal in any water heater to have much higher temps at the top and lower at the bottom, with the average around the aquastat setting, meaning we have ours turned way down. I'll give that a try. On the DHW priority wiring, I'm having a little difficulty finding straightforward info. Most diagrams/discussions include so many references to controllers and various models of components that I can't tell what the basic schematic should be. Here is my current setup:We have a single circ pump controlled by the boiler control. I just learned that the "DHW End Switch" terminal in my boiler goes to the HydroStat controller and only bypasses the thermal targeting in order to get full power from the boiler during DHW demand. My plan now is to simply add a DPDT relay (in red below) with the coil powered by the aquastat, that disconnects the signal to the two heating zone valves from their thermostats. This will will close those valves while the DHW is heating and create the priority setup. Anyone see any problems with this setup?...See MoreElectric water heater only stores 10 min of hot water
Comments (9)From what you write, you may know this already, but an electric WH is wired so that the top thermostat is the one that takes the lead, heating the top half of the tank for a quick recovery. Any time the top water is below its setpoint, the top element is on and the bottom one is not. The top thermostat is actually a double-throw switch. Once the top thermostat is satisfied, you have half a tank of hot water. The top thermo reroutes the incoming power from the top element to the bottom thermostat. The bottom thermostat then hammers the bottom element until it's satisfied, then it shuts off. Now you have a full tank of hot water. This allows you to have 2 high power (4500 Watt or whatever) elements but a WH that never uses more than 4500 Watts. It sounds like your tests seemed to show the elements and thermostats working right. Now you need to actually monitor what the upper and lower elements are doing while the tank is in operation. This requires working with hazardous voltages, so while I don't want to offend you by suggesting anything, I have to say right here that if you don't know electricity and electrical safety by heart, you should turn this over to a qualified service technician. That warning out of the way, this is pretty easy to test with the access panels off,; insulation peeled back; and neon test light, DMM, or Wiggy at the ready. For something like this I'd probably connect a test light to each element with insulated clip leads, so I could watch the transition from top to bottom element happen (or not happen). My guess: you'll find that the top thermostat's contact that closes on temp rise, the one which transfers power to the bottom element, is not closing properly or consistently., Another possibility is that although the bottom element measures the right resistance for 4500-5000 Watt WH, and the top thermo is working right, the wiring between top and bottom elements has failed. Probably close to 50 years ago, I rewired a WH on which that had happened. Maybe the wire that failed had been nicked when it was pulled in at the factory or something, but for whatever reason, it had burned in two about 1/3 of the way from top port to bottom port. Let us know how you make out with this....See Moremonicakm_gw
15 years agocynic
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15 years agodadoes
15 years agocynic
15 years agobob_k
15 years agomysteryclock
15 years ago
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