Contact Us
  • This field is for validation purposes and should be left unchanged.

A very common size, the 40 gallon water heater works well for 2 – 4 people. These tanks are often found in homes that have 1.5 bathrooms. If you are running out of hot water with a 40 gallon tank, it is often possible to upgrade to a 50 gallon tank without much modification. It typically requires a couple of extra inches of available width for the tank. Upgrading to a 50 gallon would likely provide about 15 gallons of additional hot water during your peak hour of usage during the day. This can go a long way towards ensuring you don’t run out of hot water. Electric 40 gallon water heaters typically have a first hour rating of 40-57 gallons. Gas 40 gallon water heaters on the other hand are in the 67-73 gallon range for their first hour rating.

Upsizing or Downsizing

Many times when someone finds out what size water heater they have they think about upsizing or downsizing their water heater. If you are thinking about downsizing your water heater, keep in mind that this is not always possible. Plumbing code requires that you keep at least a minimum first hour rating on the water heater that is in your home. The minimum rating on your water heater is determined by the number of bathrooms and bedrooms in your home. You can reference the chart below to see what the minimum for your home.

Water Heater 1st Hour Rating

Sometimes people also want to be able to get more hot water out of their water heater. To accomplish this, they want to upsize their water heater. If your previous water heater met the code requirements there isn’t usually an issue with upsizing your water heater from a code perspective. However, you may still run into some difficulties upsizing your water heater. The first consideration is space. Water heaters with more water in them are typically wider than your current heater. Do you have room for this? Secondly, when you are upsizing your water heater, it will typically have a larger BTU (British Thermal Units) rating on the water heater. The larger BTU rating may require a larger vent. Re-doing your venting can be an expensive proposition, check with your installation coordinator to see if this will be necessary.


If you have questions about 40 Gallon water heaters, need service/repair/installation, please do not hesitate to contact us!