To understand the concept of heat pumps, imagine a refrigerator working in reverse. While a refrigerator removes heat from an enclosed box and expels that heat to the surrounding air, a HPWH takes the heat from surrounding air and transfers it to water in an enclosed tank. During periods of high hot water demand, HPWHs switch to standard ... Feb 13, 2024 · Lacks digital control for setting target temperature. The Rheem Performance Plus Electric Tank Water Heater is well-equipped to supply hot water for showers, washing hands, or doing dishes. This 50-gallon model is the right size for a family of 3 to 5 individuals, and it comes with a 9-year warranty for peace of mind. After Canada, now Australia has found that controversial facial recognition company, Clearview AI, broke national privacy laws when it covertly collected citizens’ facial biometric...Efficient heating elements and relief valves for temperature and pressure. Diagnostic feedback and touchscreen display. Programmable vacation mode for up to 99 days. Hybrid mode with 50 percent less operating cost. Find electric water heaters with tanks big enough for your needs, with 30-, 40-, 50- or 80-gallon tanks all common. Efficient heat pump technology integrated into an electric storage water heater. 3-4 times more efficient than a traditional water heater; Available as 50 Gallon and 80 Gallon; Perfect replacement for electric storage water heaters; Eligible for 25C tax credit, saving up to $2,000 on installation costs. Shop for electric hot water heater at Best Buy. Find low everyday prices and buy online for delivery or in-store pick-up. Skip to content Accessibility Survey. ... Cordless Tea Kettle & Hot Water - Black - Black. Model: 1022060. SKU: 6578350. Not Yet Reviewed (19 from Zwilling.com) Compare. Save. Get hot water for your space with this Performance Self-Modulating Tankless Electric Water Heater. This energy-efficient water heater delivers an endless hot water supply and consistent temperature with a self-modulating technology that adjusts energy based on your hot water needs. Quick Summary. Editor’s Choice: Bosch Thermotechnology Tall Electric Storage Water Heater. "The Bosch Thermotechnology is a highly durable 50-gallon water heater packed with features for easy use …A.O. SmithSignature 900 50-Gallon Tall 10-Year Warranty 240-Volt Smart Hybrid Heat Pump Water Heater with Leak Detection & Automatic Shut-Off. 143. Multiple Options Available. • ENERGY STAR® certified 50-gallon hybrid electric water heater offers up to $385 per year in energy savings.*. • Eligible for $2,000 Federal Tax Credit, additional ...It would require some extra values for the switch from winter mode to summer mode for the 2 water heating appliances (Boiler and Hybrid Heat ...BEST ENERGY-EFFICIENT: Rheem Performance Platinum Hybrid Electric Heater. BEST FOR LARGE FAMILY: A.O. Smith Signature Premier Electric Water Heater. BEST FOR HARD WATER: EcoSmart ECO 11 Electric ...An efficient water heater will help you save on your home’s second-largest energy expense. Water heating accounts for 20% of the average home’s energy use. Efficient solutions help you spend less on hot water for the bath, kitchen and laundry room. Search incentives for you. Save $100—$700 Incentive Available.A hybrid water heater or heat pump water heater is a home appliance that is capable of generating electricity directly to heat the water within the tank like a standard …Hybrid Water Heater. Hybrid water heaters use electricity to move heat from one place to another instead of generating heat directly. Therefore, they can be two to three times more energy efficient than conventional electric water heaters. To move the heat, heat pumps work like a refrigerator in reverse. ... Tankless water heaters provide hot ... Attach the blue-coded fitting to the cold-water inlet with the arrow facing into the water heater. Attach the red fitting to the hot water outlet with the arrow pointing away from the water heater. Tighten using a pipe wrench or adjustable pliers. Measure and cut the water line connections to length as needed. Keep water warm with this Rheem Gladiator 55 Gal. tall 12-year 5500/5500-watt smart electric water heater. You can monitor your hot water usage with built-in EcoNet Wi-Fi technology. To extend tank life, it stops sediment build-up. The LeakSense leak detection system alerts you of any leaks. For durability, it offers stainless steel elements.ProTerra 80 Gal. 10-Year Hybrid High Efficiency Heat Pump Tank Electric Water Heater with Leak Detection & Auto Shutoff. Add to Cart. Compare. Top Rated. Expert Installation Available $ 1929. 00. Limit 3 per order (2894) Model# XE65T10H45U0. ... hybrid hot water heater. 120 volt heat pump water heaters.View Model. Shop ProLine® XE Voltex® hybrid electric heat pump water heaters from A. O. Smith. More than 3 times as efficient as a standard electric water heater, easy to install, and simple to operate.The U.S. Department of Energy estimates that in homes using 41 gallons or less of hot water, on-demand tankless units can conserve between 24% to 34% more energy than tank water heaters. ... hybrid water heaters can save you up to $3,000 in 10 years in energy costs compared to traditional units. More Details . Average Installation Price by ...A hybrid water heater is a heat pump water heater that collects heat from the outside environment and raises the water temperature. It is more energy-efficient, cost-effective, and eco-friendly than other water heater types. Learn how it works, how it compares to other water heaters, and its benefits for families. See moreSep 16, 2021 ... My electric hot water heater just failed, planning to replace it with a hybrid. We are in a 2nd floor condo just outside of Boston MA, so we ... Find the Water Heater to Fit Your Needs. There are several factors to consider when choosing a water heater – gas or electric, tank or tankless. Tank sizes range from 20- to 80-gallon capacities and depend on the building occupants or household size and amount of water usage at peak times. Regardless of which hot water heater system you ... Tempra 24 Plus Adv Flow Control and Self-Modulating 24 kW 4.68 GPM Residential Electric Tankless Water Heater. Add to Cart. Compare. More Options Available. Expert Installation Available $ 329. 00. Buy 3 or more $ 296.10 (2291) Model# RETEX-13. Rheem. Performance 13 kW Self-Modulating 2.54 GPM Tankless Electric Water Heater. Efficient heat pump technology integrated into an electric storage water heater. 3-4 times more efficient than a traditional water heater; Available as 50 Gallon and 80 Gallon; Perfect replacement for electric storage water heaters; Eligible for 25C tax credit, saving up to $2,000 on installation costs. During periods of high hot water demand, HPWHs switch to standard electric resistance heat (hence they are often referred to as “hybrid” hot water heaters) automatically. ... Electric/Heater – This high-demand setting is the least energy-efficient, using only the electric element to heat water; Vacation & Timer (not available on all ... If you’re feeling lukewarm about your current hot water heater or are looking to install one in your new home, Lowe’s can help. We have a full selection of electric water heaters, gas water heaters, tankless water heaters, hybrid heat pump water heaters and water heater accessories. What is a Hybrid Water Heater, Sounds cool doesn't it? A hybrid water heater is also known as a heat pump water heater and is a tank-style heater for your ...A hybrid water heater is a heat pump water heater that collects heat from the outside environment and raises the water temperature. It is more energy-efficient, cost-effective, and eco-friendly than other water heater types. Learn how it works, how it compares to other water heaters, and its benefits for families. See moreShop for electric hot water heater at Best Buy. Find low everyday prices and buy online for delivery or in-store pick-up. Skip to content Accessibility Survey. ... Cordless Tea Kettle & Hot Water - Black - Black. Model: 1022060. SKU: 6578350. Not Yet Reviewed (19 from Zwilling.com) Compare. Save.Consumer Reports is a trusted source for unbiased reviews and ratings on various products, including hot water heaters. When it comes to making a decision about which hot water hea...View Model. Shop ProLine® XE Voltex® hybrid electric heat pump water heaters from A. O. Smith. More than 3 times as efficient as a standard electric water heater, easy to install, and simple to operate.Do you often run out of hot water? Do your family members like taking long hot showers? We have a solution to reduce your chances of freezing the next time you ...Feb 15, 2024 · Stiebel Eltron DHC Trend Point-of-Use Electric Tankless Water Heater. Rheem 18kw Tankless Electric Water Heater. Rheem 13kw Tankless Electric Water Heater RTEX-13. Eemax 27kW ELECTRIC TANKLESS ... Aug 3, 2023 ... ... Hybrid Electric Heat Pump Water Heater. John Resso, Contractor ... Smith Voltex® AL Smart Hybrid Electric Heat Pump Water Heater Live-Fire ...For people using gas water heaters, two options are offered--natural gas or propane. According to Energy Star, 15 percent of a home’s energy use is attributed to heating water. Bot...BEST ENERGY-EFFICIENT: Rheem Performance Platinum Hybrid Electric Heater. BEST FOR LARGE FAMILY: A.O. Smith Signature Premier Electric Water Heater. BEST FOR HARD WATER: EcoSmart ECO 11 Electric ... Performance Plus 50 Gal. 5500-Watt Elements Medium Electric Water Heater w/9-Year Tank Warranty LED Indicator & 240-Volt ... hot water heater electric. hot water tank ... Upgrade your home's hot water system with this Rheem ProTerra 80 Gal. 10-Year Hybrid High Efficiency Smart Tank Electric Water Heater. This energy-efficient appliance provides an estimated energy cost savings of $490 per year.And, tankless water heaters are still more energy-efficient than storage tank water heaters. In general, the operating costs of the two types of water heaters are nearly the same. The average annual operating costs of a hybrid water heater is about $190 per year. Gas fueled tankless water heaters operating costs are about $228 per year.Jan 15, 2024 · The initial cost is what turns most people off from purchasing a hybrid water heater, as traditional water heaters cost significantly less than hybrid water heaters do. The average tankless heater goes for about $500-$1700, while the average tank-based heater goes for about $400 – $800. While the generally high humidity in Florida can decrease the efficiency of hybrid hot water heaters, the warm air and warmer water temperature increase the overall efficiency of the unit. Heat pump water heaters not only work in Florida but can also be a huge benefit in homes. These water heaters can save up to 64% on energy costs for …Signature 100 40-Gallons Tall 6-year Warranty 40000-BTU Natural Gas Water Heater. 613. #13. A.O. Smith. Signature 100 19-Gallon Compact 6-year Warranty 1500-Watt 1 Element Point Of Use Electric Water Heater. 348. #14. A.O. Smith. Signature 100 28-Gallon Lowboy 6-year Warranty 4500-Watt Double Element Electric Water Heater.Cost of a Hybrid Water Heater. One problem with hybrids is their initial cost. You can buy a traditional 50-gallon electric water heater for around $500, whereas a 50-gallon hybrid water heater might cost $1,500 or more. The good news is that state-sponsored rebates and federal tax incentives may be available to help lower the cost.Because of these factors, hybrid water heaters can consume significantly less energy and therefore reduce energy costs. Over the course of its life, typically at least ten years, a hybrid heat pump can save a household $3,500. Heat pump hot water heaters also have a longer lifespan than conventional water heaters. A hybrid water heater has …In addition to the heat pump technology, this model also has two heating elements that help the water heater recover quickly during periods of high demand. This ...It is recommended that the hybrid water heater be installed where ambient temperatures DO NOT exceed 145°F (63°C). Insufficient air exchange will result in increased energy consumption levels. ... This Performance Platinum hybrid smart tank electric water heater gives your home hot water, while also saving you on energy costs. It's highly ...Some gas and electric tankless water heaters can deliver enough hot water for an entire household. Whole-home gas tankless water heaters typically range in sizes from 140,000 BTU to around 199,000 BTU; choose the appliance capability based on the amount of hot water you need for a home or business. You can find:Electric Water Heaters. Heat your water more efficiently than ever before with Bradford White’s electric tank type water heaters. With a variety of sizes, our electric line delivers outstanding performance for any water heating need. ... Available in a variety of tank sizes so you can make sure you have all the hot water your family needs ...During periods of high hot water demand, HPWHs switch to standard electric resistance heat (hence they are often referred to as “hybrid” hot water heaters) automatically. ... Electric/Heater – This high-demand setting is the least energy-efficient, using only the electric element to heat water; Vacation & Timer (not available on all ...Signature 100 40-Gallons Tall 6-year Warranty 40000-BTU Natural Gas Water Heater. 613. #13. A.O. Smith. Signature 100 19-Gallon Compact 6-year Warranty 1500-Watt 1 Element Point Of Use Electric Water Heater. 348. #14. A.O. Smith. Signature 100 28-Gallon Lowboy 6-year Warranty 4500-Watt Double Element Electric Water Heater.Feb 13, 2024 · Lacks digital control for setting target temperature. The Rheem Performance Plus Electric Tank Water Heater is well-equipped to supply hot water for showers, washing hands, or doing dishes. This 50-gallon model is the right size for a family of 3 to 5 individuals, and it comes with a 9-year warranty for peace of mind. Ecosmart Tankless Electric Water Heater. You’ll get hot water on demand without blowing your budget with the Ecosmart Tankless Electric Water Heater. This electric unit can heat three gallons per minute when the incoming water temperature is as low as 37 degrees Fahrenheit, making it an excellent option for homes in the Northern …Qualifying Credit Amounts and Expenses. 2023 through 2032: 30%, up to a maximum of $1,200 (water heaters, heat pumps, biomass stoves, and boilers have a separate annual credit limit of $2,000), no lifetime limit Get details on the Energy Efficient Home Improvement Credit. *For 2022, biomass stoves and boilers are treated as a Residential Clean ...Are you considering upgrading your hot water heater? With so many options available on the market, it can be challenging to determine which one is best for your home. One type of h...Hybrid plus mode – Maximizes production of hot water for high demand situations. Electric only mode – Least energy-efficient mode, used only when air is too cold for heat pump modes. Vacation Mode – Minimizes energy use and maximizes savings during periods when users are away.The clearance space needed around a hot water heater is dependent upon whether the heater is a gas or electric model. Twenty-four inches of service clearance in front and two inche...Combined to meet the hot water requirements of businesses, the Hybrid Hot Series by Noritz® utilizes the latest in tankless and tank storage technologies to create a powerful and reliable solution for businessowners. The Hybrid Hot also offers common venting for multiple units to ensure endless hot water is always available. Noritz is proud to ...GreenTronic 7000 T Hybrid Electric Water Heater. Efficient heat pump technology integrated into an electric storage water heater. 3-4 times more efficient than a traditional water heater. Available as 50 Gallon and 80 Gallon. Perfect replacement for electric storage water heaters. Eligible for 25C tax credit, saving up to $2,000 on installation ...Efficient heat pump technology integrated into an electric storage water heater. 3-4 times more efficient than a traditional water heater; Available as 50 Gallon and 80 Gallon; Perfect replacement for electric storage water heaters; Eligible for 25C tax credit, saving up to $2,000 on installation costs.Jul 10, 2023 ... Heating: Since hybrid water heaters rely on the air around them to heat the water, they don't always get the water as hot as tank or tankless ...Consumer Reports is a trusted source for unbiased reviews and ratings on various products, including hot water heaters. When it comes to making a decision about which hot water hea...A hybrid water heater, or heat pump water heater, uses heat from outside air drawn into the appliance’s evaporator coil. The evaporator coil contains refrigerant, allowing it to absorb heat from the air. Finally, a heat exchanger heats water within the tank to the desired temperature before it passes from the heater tank into your home’s ...Stiebel Eltron DHC Trend Point-of-Use Electric Tankless Water Heater. Rheem 18kw Tankless Electric Water Heater. Rheem 13kw Tankless Electric Water Heater RTEX-13. Eemax 27kW ELECTRIC TANKLESS ...Items 1 - 15 of 15 ... "electric hybrid water heater" · Zojirushi - VE Hybrid 4L Water Boiler & Warmer - Stainless Dark Brown · Zojirushi - VE Hybrid 5L...Sep 13, 2021 · 1 Benefits Of Having A Hybrid Hot Water Heater: Pros And Unique Features; 2 Things To Consider Before Buying A Hybrid Hot Water Heater. 2.1 Hybrid Heat Pump Water Heater Capacity; 2.2 Installation Space; 2.3 Energy Efficiency; 2.4 Stiebel-Eltron ACCELERAⓇ 300 Heat Pump Water Heater; 2.5 Rheem PERFORMANCE PLATINUM™ EcoNet Enabled Hybrid ... Combined to meet the hot water requirements of businesses, the Hybrid Hot Series by Noritz® utilizes the latest in tankless and tank storage technologies to create a powerful and reliable solution for businessowners. The Hybrid Hot also offers common venting for multiple units to ensure endless hot water is always available. Noritz is proud to ...The heat pump removes a small amount of heat from the surrounding air, heats the water and moves the cooler air back into the room. The GE GeoSpring™ hybrid electric water heater produces the same amount of hot water as a traditional water heater, but with greater efficiency. Think of the hybrid water heater as a refrigerator working in reverse.Get the Ruud Ultra™ Hybrid Electric Water Heater today and enjoy years of energy-saving and worry-free hot water. Save Money & Energy. Save up to $491 per year in energy costs—that’s almost $5,000 over 10 years! Energy Saving Scheduling. Program your water heater to match your needs throughout the day—higher production during high use ...Types of Water Heaters. It's a good idea to know the different types of water heaters available before you purchase one: Conventional storage water heaters offer a ready reservoir (storage tank) of hot water which is adequate for everyday use.However, there are some instances, such as when more than one use for hot water is occurring or when …Efficient heat pump technology integrated into an electric storage water heater. 3-4 times more efficient than a traditional water heater; Available as 50 Gallon and 80 Gallon; Perfect replacement for electric storage water heaters; Eligible for 25C tax credit, saving up to $2,000 on installation costs.A.O. Smith Signature 900 50-Gallon Tall 10-Year Warranty 240-Volt Smart Hybrid Heat Pump Water Heater with Leak Detection & Automatic Shut-Off. A.O. Smith Signature 100 40-Gallon Short 6-year Warranty 40000-BTU Natural Gas Water Heater. View More. A.O. Smith Signature 500 50-Gallons Tall 6-year Warranty 50000-BTU Natural Gas Water …Feb 22, 2024 · There are two basic types of tankless water heaters to consider: whole-house and point-of-use. Whole-house models, like the Rinnai V53DeN Tankless Hot Water Heater or Rheem Performance Self-Modulating 7.03 GPM Tankless Electric Water Heater, have flow rates substantial enough to support multiple fixtures simultaneously. ProLine ® XE Hybrid Electric Heat Pump 50-Gallon Tank Water Heater. User-friendly electronic interface. Reduces water heating cost by up to 73%. High-Efficiency and ENERGY STAR ® Certified with a UEF of 3.45. 10-year limited warranty. View All Hybrid Heat Pump Water Heaters.Shop for electric hot water heater at Best Buy. Find low everyday prices and buy online for delivery or in-store pick-up. Skip to content Accessibility Survey. ... Cordless Tea Kettle & Hot Water - Black - Black. Model: 1022060. SKU: 6578350. Not Yet Reviewed (19 from Zwilling.com) Compare. Save.Solar Hot Water Heater Cost. The cost of a solar water heater varies depending on the type of system, tank size, location, and other factors. According to our research, solar water heater installation costs between $3,000 and $9,000.* ... A technician may suggest an extra gas or electric water heater backup system to ensure a continuous hot ...Feb 13, 2024 · Rheem Performance Platinum Series Gladiator 50-Gallon Electric Water Heater: 4.4: $799.00: Excellent (12 years) 50 gallons: View More: Rheem Performance Standard 40-Gallon Electric Water Heater: 4 ... Water Heating. Heat Pump Water Heaters. We were proud to introduce the first 240V Hybrid Electric Heat Pump water heater to the market in 2009, but we didn’t stop there. We have continued to innovate in the category, adding a touch screen control, developing a 120V Plug-in Heat Pump for easy gas replacement, and finding new ways to save you ...To help you find the most well-rated and efficient electric water heater for your home, I’ve compiled a well-researched list of the seven best electric water heaters on sale today. Here are my results. 1. A.O. Smith Voltex Hybrid Heat Pump Electric Heater: 9.2/10. Overall best electric water heater. $3,027.23.Aug 3, 2023 ... ... Hybrid Electric Heat Pump Water Heater. John Resso, Contractor ... Smith Voltex® AL Smart Hybrid Electric Heat Pump Water Heater Live-Fire ...Aug 3, 2023 ... ... Hybrid Electric Heat Pump Water Heater. John Resso, Contractor ... Smith Voltex® AL Smart Hybrid Electric Heat Pump Water Heater Live-Fire ...Electric tank water heaters are energy-efficient solutions for your home’s water heating needs. A. O. Smith’s electric tank water heaters have a UEF rating between .89 and 3.45, helping you save energy in your home. Although the recovery rate of electric water heaters is slower compared to gas water heaters, electric models can be less ...Inside a heat pump, or hybrid, water heater, there's an evaporator coil that stores refrigerant. The refrigerant helps pull warm outside air into the heater ...
Performance Manufactured Housing 30 Gal. Tall 6-Year 30,000 BTU Convertible Natural Gas/LP Direct Vent Tank Water Heater. Add to Cart. Compare. Expert Installation Available $ 839. 00 (5) Model# XG29T06MH32U1H. Rheem. Performance Manufactured Housing High Altitude 29 Gal. Tall 6-Year 28,000 BTU Convertible Natural Gas/LP Water Heater.. Champagne sparkling wine
Any time you use hot water, cold water will flow into the bottom of the tank and the water heater will turn on and start heating. The water heater will also need to run on occasion to reheat the water in the tank, so it always stays at the correct temperature. When heating, a hybrid water heater starts moving refrigerant throughout the unit.Hybrid hot water heaters are generally a bit taller than standard water heaters. They typically would not fit in a crawl space or anywhere that has a low ceiling. The specs on the water heater will be available on manufacturer websites. Noise. Hybrid hot water heaters do make some noise. It’s comparable to the noise level of a window air ...The Rheem ProTerra Electric Hybrid is the smartest, quietest and most efficient water heater on the market. This ProTerra hybrid model features LeakGuard, the integrated the 360degree leak detection system and the auto shut-off valve system that shuts off incoming water, locks water in the tank and protects your home. It's smart: with its built-in WiFi …This Performance Platinum hybrid smart tank electric water heater gives your home hot water, while also saving you on energy costs. It's highly durable for long-term use with stainless steel elements that prevent build-up. It's also a smart appliance with built-in EcoNet Wi-Fi. You can manage the heating schedule and track weekly, monthly and yearly …A.O. SmithSignature 900 50-Gallon Tall 10-Year Warranty 240-Volt Smart Hybrid Heat Pump Water Heater with Leak Detection & Automatic Shut-Off. 143. Multiple Options Available. • ENERGY STAR® certified 50-gallon hybrid electric water heater offers up to $385 per year in energy savings.*. • Eligible for $2,000 Federal Tax Credit, additional ... Get hot water for your space with this Performance Self-Modulating Tankless Electric Water Heater. This energy-efficient water heater delivers an endless hot water supply and consistent temperature with a self-modulating technology that adjusts energy based on your hot water needs. Dec 19, 2018 ... I had an oil boiler previously for domestic hot water. I've only had my HPWH since April but couldn't be happier with it. My local electric ...Our electric water heater ratings include the following types: Electric tanked water heaters, electric tankless, and electric heat pump. ... U.S. Boiler Company Recalls 2,500 Gas Hot-Water Boilers ...Aug 31, 2023 · Quick Summary. Editor’s Choice: Bosch Thermotechnology Tall Electric Storage Water Heater. "The Bosch Thermotechnology is a highly durable 50-gallon water heater packed with features for easy use and maintenance. It is highly efficient and saves fuel". Best Value: Westinghouse 80-Gal. And because the heat pump is on top, a hybrid water heater needs as much as 7 feet of clearance from floor to ceiling.ProLine XE® Voltex® 66-Gallon Hybrid Electric Heat Pump Water Heater Model HPTU-66N. 4.5. (461) ENERGY STAR® certified. 79-gallon first hour rating. 10-Year Warranty. “Well designed, easy to use and gives lots of flexibility of use. Energy saving aspect is very good, and the "built-in A/C" is a great fringe benefit." Typically, tankless water heaters provide hot water at a rate of 2–5 gallons (7.6–15.2 liters) per minute. Gas-fired tankless water heaters produce higher flow rates than electric ones. Sometimes, however, even the largest, gas-fired model cannot supply enough hot water for simultaneous, multiple uses in large households. And, tankless water heaters are still more energy-efficient than storage tank water heaters. In general, the operating costs of the two types of water heaters are nearly the same. The average annual operating costs of a hybrid water heater is about $190 per year. Gas fueled tankless water heaters operating costs are about $228 per year.Tank and Tankless. With an endless supply of hot water, lower pressure drop, and no limitation of hot water flow rate, the Hybrid Hot combines features of both technologies …Tankless water heaters take up much less space than storage water heaters as they heat the water directly. Discover why one of them is best for your home. Let’s dig into how to turn on a water heater, whether gas or electric, and when it might be time... If you want a constant supply of hot water ...In the battle between gas and electric water heaters, electric water heaters win out from an efficiency perspective. Conventional gas water heaters typically have EF numbers ranging from 0.5 to 0.7, while electric water heaters can have EF numbers higher than 0.9. In general, most of the energy loss from gas water heaters occurs during the ....