Replacing a 40 gallon and 50 gallon water heater with Gas or Electric Tankless?ĥ0 Gallon tank-type water heater that supplies hot water to the whole home could be replaced with a 5 to 8.5GPM gas tankless water heater based on the number of your showerheads and utility faucets. However, tankless water’s hot water flow is endless. Now, if you want a similar tankless water heater that can run 2 showers at a time, then 5 GPM is the best size. In case you use a kitchen faucet simultaneously, it’s hard to run more than one shower, though. So, if you run 2 showers simultaneously, the maximum temperature will sustain for 10 minutes which is the average shower season. If you use a 2.5 GPM single showerhead, then the temperature will sustain for no longer than 20 minutes. Most dermatologists recommend that 98☏ to 101☏ is the best temperature for having a warm shower. Your concern should be how long you can take a shower with a 40 Gallon Tank water heater? The number of showers isn’t the matter here. How many showers can you have in a 40 gallon tank? So Here’s The Equivalent Tankless So, If your total water uses remains around 4 GPM, including bathroom, kitchen, and laundry, then a 5 GPM tankless water heater can replace a 40 Gallon unit.Īlso, you can increment or decrement the size according to your flow rate calculation. However, a small 3 GPM tankless water heater can do the same with a low flow rate. If you use 5GPM water, the 40 Gallon tank delivers hot water for 6 minutes before the temperature falls by 116F.īut a 5 GPM tankless water heater can limitlessly deliver hot water at 120F. So what size tankless water heater is equivalent to this 40 gallon unit? So, you can’t mix any more cold water with it. When you use 10 gallons of hot water, the tank inside temperature falls from 160F to 135F.Īfter using 20 gallons of hot water, the tank inside temperature falls from 160F to 116F.Īfter, after using 30 gallons of hot water, tank water temperature falls over 102Fįinally, after using 40 gallons of tank water, the tank water temperature becomes as cold as 91.5F, which you exactly need to have a shower. When you use the hot water from the tank, cold water enters inside, and the temperature gradually falls. However, a 2.5 GPM faucet will dispose of 1.51 Gallons of 160F hot water from the tank and 0.995 Gallons of cold water from the tap line.īut, as you know, the tank temperature will gradually decrease, and you need to mix more hot water and less cold water. So, we find the mixing ratio of (160F)hot and (60F)cold water is 1: 0.659 to get the derived 120F water output. So, you need to MIX 1 Gallon of 160F water + 0.659 Gallon of 60F water to get an output of 120F hot water. Suppose your ambient temperature is 60F, and you need 120F hot water at any of your kitchen sink, laundry, or utility faucets.Ī typical tank-type water heater raises the temperature to 160F in MAX, and imagine, 40 gallons of 160F hot water remains reserved at the tank. (2 Mins in this case.)īut, as you don’t need that 160F outlet temperature, you’ll mix some cold water from the tap line. If you double the flow rate, the timing will be half. If you dispose of hot water from the 40-gallon tank to any 2.5 GPM faucet/outlet, the gradual temperature decrement will look like But how many minutes you’ll get the hot water flow, that depends on the tank size. How Many GPM is a 40 Gallon Water Heater? Let’s Find Equivalent Tankless 7 FAQs about Tankless Water Heater to Replace a 40 Gallon Unit.Number Of Family Members vs Size of Tankless Water Heater.How much do you save with a tankless water heater?.What is the average life of a tankless water heater? (That's Equivalent to 40 Gallon).Reliable Tankless Water Heater Brands to Replace Your Old 40 Gallon Unit?.Should I turn off the tankless water heater if the water is off?.
Replacing a 40 gallon and 50 gallon water heater with Gas or Electric Tankless?.How many showers can you have in a 40 gallon tank? So Here's The Equivalent Tankless.How Many GPM is a 40 Gallon Water Heater? Let's Find Equivalent Tankless.