30-Gallon Hot Water Heater Vs. 40-Gallon Hot Water Heater

Heating the water in your house is one of the largest expenses in your home. By some estimates, it is often the second-largest expense, accounting for 11 percent of your utility bill. So making sure that you choose the right water heater for your needs and family size will directly impact your budget. A hot water heater that is too large will only have you needlessly keeping water hot that you don't use, and a heater that is too small will leave you shivering in the shower when the hot water runs out.

30-Gallon Hot Water Heater Vs. 40-Gallon Hot Water Heater

Regular or High Demand

Make sure that you have the right size water heater for your needs. Besides running a hot bath and dishwater, regular demand for hot water would include using a washing machine and automatic dishwasher. High demand would be meeting the needs of teenagers and the additional hot water required for whirlpool tubs and oversize baths. Since you will probably have your hot water heater for at least 10 years, look into the future of what your needs will be when choosing a hot water heater.

When Is A 30-Gallon Tank Appropriate?

A 30-gallon hot water heater is really only appropriate in one situation. If your home has only one or two people using hot water at the regular demand level, you can get away with using the smaller tank if it is heated with gas. In actuality, you should only consider a 30-gallon tank if your space for the hot water heater is very limited.

When a 40-Gallon Tank Is Appropriate

A 40-gallon hot water heater gives you a few more options. A 40- or 50-gallon hot water heater is usually what most houses will have installed. If there are one or two people in the home making a high demand for hot water heated with gas, or making regular demand with hot water heated by electric, you can used a 40-gallon tank. If your home has 3 or 4 people making regular demands for hot water heated with gas, you can also use a 40-gallon tank. Other options will require larger tanks.


The price difference between a 40-gallon hot water heater and a 30-gallon tank are negligible. The difference may be less than $10. It will cost more for the 40-gallon tank to keep the water heated all the time, but if you purchase a well-insulated tank, this cost can be kept under control and the difference will probably be worth it to have hot water when you need it.

Other Considerations

Another consideration in your purchasing decision is recovery rate (number of gallons of water that can be heated in an hour). Find out how quickly your tank recharges after use. The standard recharge is around 40 gallons an hour, but a fast recharge is 55 gallons an hour. Learning the BTUs of the tanks will tell you how quickly a tank can heat the water.