HOT WATER - FAQ and Information

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INDEX - Jump to HOT WATER TOPICS

Hot Water | Hot Water Heaters | Recirculating hot water system | Rinnai Tankless Water Heaters | TANKLESS Water heaters | Water Temperatures - DESIRED | Water Temperatures - DISH WASHER | Water Temperatures - SCALDING | Rinnai RU98e Tankless Hot Water Heater |

HOT WATER

Almost all world-wide safety organizations have come out in favor of setting your home Hot Water Heater to 120 degrees Fahrenheit (not higher than 120). You may want your Dish washer to use 140 Degrees Fahrenheit, IF trying to remove stubborn food from dishes, but 140 Degrees Fahrenheit on human or animal skin will probably cause dangerous scalding, and should be avoided. Setting your water temperature to more than 120 degrees Fahrenheit, may cause scalding, especially for children or older adults (as they may not get out of the hot water in time to prevent scalding (which create skin burns).

WATER TEMPERATURES - SCALDING

I am NOT Responsible for any Errors - Use at your own risk I ASSUME NO LIABILITY - You do things at your own risk Always check facts for your self. Scalding is a burning from heated fluids such as boiling water, steam, or home hot water heating systems. Children are the most likely to be scalding by hot water. Scalding can cause dangerous or even fatal burns.

Scalding Tables and Charts

Images for scalding water temperature chart Time and Temperature to Scald Scalding from Hot Water - PSEG.com Make sure your water heater is set to a safe temperature for home use. Use the industry charts below to provide guidance to avoid scalding. Check the water temperature before placing a child in the bathtub. Never leave a child alone or with other young children in the bathtub. Always check facts for your self. Most water heaters are unlikely to scald an adult occupant (because the adult will get out of the water, UNLESS incapacitated) Table of Hot Water Scalding Temperatures and Length of Exposure: Water Temperature Exposure Time Effects of Exposure to VERY Hot Water
Water at 100 degF or below See Safety Note Water at 120 degF 5 minutes 2nd & 3rd degree burns on adult skin Water at 130 degF 30 seconds 2nd & 3rd degree burns on adult skin Water at 140 degF 5 seconds 2nd & 3rd degree burns on adult skin Water at 150 degF 1.5 seconds 2nd & 3rd degree burns on adult skin Water at 160 degF .5 second 2nd & 3rd degree burns on adult skin degF = F = Degrees Fahrenheit Safety Note: Hot Water Scald Burn Warning for Infants, Children, & Elderly: Great care must be taken when exposing infants or children to warm or hot water as they can be badly burned quickly and at shorter exposure times.

WATER TEMPERATURES DESIRED

I am NOT Responsible for any Errors - Use at your own risk I ASSUME NO LIABILITY - You do things at your own risk Always check facts for your self. The consensus seem to be that you want the temperature of your household hot water to be 120 Degrees Fahrenheit. You may want your Dish washer to use 140 Degrees Fahrenheit, IF trying to remove stubborn food from dishes. My dishwasher has an "HIGH TEMP WASH" option which raises the dish washer water temperature from 120 Degrees Fahrenheit to 140 Degrees Fahrenheit. Of course, using the HIGH TEMP WASH will also raise my cost of electricity to clean dishes. Raleigh, North Carolina, USA, LAW requires water heater installers to set the hot water temperature to 120 Degrees Fahrenheit. There are hundreds of national and international standards set forth by the major plumbing code making bodies, which specify a maximum temperature of 120F for delivered (the water temperature at the faucet) hot water. As with any hot water heater, the further the heater is from the output faucit, tub, shower, wash basin,... - the longer it takes to get hot water at the desired temperature at the desired faucet. As a waterless hot wate heater is MUCH smaller than a conventional hot water water, some home-owners have the new tankless water heater installed closer to the location of the faucets - to enable them to get hot water sooner. All hot water pipes should be insulated to cut down on wasted heat. If you have the space and the money, you can have a recirculating hot water system installed - it cuts down on the time that you have to wait until you get hot water at the faucet, but it also increases the cost of your hot water.

WATER TEMPERATURES - DISH WASHER

Always check facts for yourself. The consensus seem to be that you want the temperature of your household hot water to be 120 Degrees Fahrenheit. You may want your Dish washer to use 140 Degrees Fahrenheit, IF trying to remove stubborn food from dishes. My dishwasher has an "HIGH TEMP WASH" option which raises the dish washer water temperature from 120 Degrees Fahrenheit to 140 Degrees Fahrenheit. Of course, using the HIGH TEMP WASH will also raise my cost of electricity. Thus I can keep my water heater set to 120 Degrees Fahrenheit and use the HIGH TEMP WASH, WHEN needed, to raise the dish wasther (only) temperature to 140 Degrees Fahrenheit when I need to remove stubborn food stais from dishes.

HOT WATER HEATERS

TANKLESS WATER HEATERS

In the USA and even more so in Europe, Tankless water heaters are being installed more and more often (instead of the conventional hot water heater, which has a tank in which to store the created hot water). A tankless hot water heater, as the name implies, has no tank to hold the generated hot water - instead, hot water is generaterd on demand (only when a hot water faucet is turned on). It takes more to generate hot water this way, than a water heater with a tank (the conventional, or most often used in the USA) water heater, but since hot water is only generated when needed (on demand), instead of all of the time, the actual cost of hot water generated by a tankless hot water heater is less (than that of a conventional hot water heater).

RINNAI TANKLESS WATER HEATERS

While you can always find someone who disagrees, the most popular tankless hot water heater (at least in the USA) is made by Rinnai. Reports show that you should expect the lifetime of a Rinnai tankelss hot water heater to be about double that of a typical water heater with a tank (no guarantee, but typical lifetimes are supposed to be about 18 to 20 years). The most effective tankless hot water heaters are deemed to to use natural gas or propane. Rinnai does NOT make an electric version, listing several drawbacks to such a system NOTE that sice they use some computerized circuitry, even natural gas tankless hot water heaters will need some electricity, ELSE they won't run. Thus a tankless water heater will NOT run during a power failure (I run mine on a whole house standby natural gas generator, so mine works during a power outage). Rinnai Tankless Water Heaters require 120 volts AC, 60 Hz and less than three amps. #1 Tankless Water Heater Buyer's Guide - Rinnai Rinnai says: "Because tankless water heaters provide hot water only when its needed, they can save you up to 40%* on your energy bill. They feature Energy Factors of 0.82 up to 0.96, while tanks are typically 0.60." We have a 199,000 BTU natural gas Rinnai tankless hot water heater, model RU98e (REU-KB3237WD-US). The RU98e has a built-in capability of cycling an external pump at pre-set intervals and temperatures. The RU98e is supposed to handle 4 showers and some other hot water demands, at the same time (so says Rinnai, but not seeing tath on-online, just now). Rinnai Tankless Gas Water Heaters have a direct-spark electronic ignition, thus there is NO pilot light (but electricity is required). Energy Factor: 0.95 for Natural Gas and Propane Electrical Consumption: Normal: 63 Watts Standby: 2 Watts Anti-Frost Protection: 168 Watts

RECIRCULATING HOT WATER SYSTEM

If you have the space and the money, you can have a hot water recirculating system installed. The purpose of this pipe is to cause some hot water demand at the far end of your hot water pipe run - thus, as an example, every 5 minutes the recirculating pipe may be activated (automatically), pushing some hot water closer to your faucets, shortening the delay from when you turn on a hot water faucet to when you actuall receive hot water at the desired location. Of course, this increases your cost of having hot water, and requires a recirculating water pump and a few other related items for it to function. Do hot water recirculation systems work? - 2007 Hot Water Recirculation Systems -- how much energy waste? - 2008 How to Install a Recirculating System : How-To : DIY Network

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