How to Size the Right Water Heater for Your Home

Water heater

The water heater is responsible for supplying hot water to your facets and appliances such as your washer and your dishwasher. It heats up the water. This allows you to get hot water when you need it like for showers and baths.

Without a water heater, your water would be cold. The water is heated by either gas, propane or electric.

There are two types of water heaters. You can choose from a tankless water heater which heats the water on demand (when it’s needed) and it’s considered an eco-friendly option. The alternative is a traditional water tank which houses hot water.

Sizing Your Household Water Needs

Everyone’s consumption requirements are different. This will depend on the number of people in your home, the number of bathrooms and bedrooms, the number of appliances you have and the frequency of hot water usage. These variables will determine the size of a tankless or a tank water heater you’ll need for your home.

Your household water needs will depend on the Number of Appliances and Bathrooms you have.
Having a undersized water tank is not ideal. It makes the water heater work harder. The load ends up lowering the lifespan of your water heater which can cause it to break down.

The charts below will give you a guideline of the size water heater you will need for your home.

Tankless Water Heater Sizing Chart

When considering a tankless water heater, you will need to figure out your average usage. Most homes use between 3.0 – 7.0 gallons of water per minute (GPM). This consumption is based on having a single shower running, a dishwasher and the washing machine running at the same time.

Bath Facet – Typical Water Flow Gallons per Minute (GPM) – 0.5 to 1.5 GPM
Kitchen Facet – Typical Water Flow Gallons per Minute (GPM) – 3.0 to 7.0 GPM
Shower – Typical Water Flow Gallons per Minute (GPM) – 1.0 to 2.0 GPM
Dishwasher – Typical Water Flow Gallons per Minute (GPM) – 1.0 to 2.5 GPM
Washing Machine– Typical Water Flow Gallons per Minute (GPM) – 1.5 to 3.5 GPM

Tank water heater sizing chart

The most common type of water heater in North America. The tank water heater stores gallons of hot water up to 60 gallons depending on the size. Most homes will have their tank water heater supplied by their local gas company, through a monthly rental program.

However since it is a low upfront cost, many GTA (Greater Toronto Area) customers are opting to buy the water heater themselves. This eliminates any on-going, rental fees which you need to pay.

The number of bedrooms and bathrooms you have in your home will give you a benchmark on the size of tank water heater you should be investing in.

1 to 1.5 Bathroom Home

1 Bedroom – 20 Gallon Tank
2 Bedroom – 30 Gallon Tank
3 Bedroom – 40 Gallon Tank

2 to 2.5 Bathroom Home

2 Bedroom – 50 Gallon Tank
3 Bedroom – 50 Gallon Tank
4 Bedroom – 50 Gallon Tank
5 Bedroom – 60 Gallon Tank

3 to 3.5 Bathroom Home

3 Bedroom – 50 Gallon Tank
4 Bedroom – 60 Gallon Tank
5 Bedroom – 60 Gallon Tank

When my furnace quit this winter the folks from Green were at my house within 30 minutes. They quickly diagnosed the problem and provided a budget friendly quote for a replacement. A crew was there first thing the next morning and had everything running within 2 hours. Hassan, Andre and his crew were very professional.

Benjamin J.

Christmas Eve and our furnace decided to take a holiday. Phoned Green Heating and Air and the technician was here in 20 mins. He completed a repair but warned that we may need a new circuit board. Sure enough the furnace shut down again and when we called back they confirmed they had a board and could install it after midnight. Exactly at midnight our doorbell rang, the circuit board was replaced and we’ve been warm and toasty ever since. Thank you for going above and beyond on Christmas Eve. 100% recommend this company which truly provides 24 hour emergency services.

Janet G.

Wow so impressed at how quickly the team at Green Heating & Air responded. We had our heating breakdown one evening and in the middle of winter, it’s never fun sitting in the cold. They arrived early the next morning and was able to fix the issue with our boiler and tank immediately. They were transparent about the price and process, and what products they needed to purchase.

Michelle K.

If you think great customer service is a thing of the past, then you have not worked with Hassan and the team at Green Heating and Air Inc. They did outstanding work in installing a new AC and air handler system in a very tight furnace room serving four floors. The project was done on time with no budget surprises and after installation follow up was something you rarely experience today. Cannot say enough positive things about our experience.

Jim G.

Hassan and his team completely replaced my boiler and got it up to safety standards in my old home. Hassan addressed every issue we ran into and responded to my calls and messages very quickly! He was very friendly and was patient in answering all my questions. I highly recommend him and his team, and feel confident that I have them to turn to with any issues regarding my heating!

Gianne H.

Hassan is amazing. We have a new build home with a heating system that is terrible. We had an issue and called Hassan who came to fix the issue. While fixing the pump, he told us how terrible the system we had was. He recommended getting a new system. My husband and I agreed.Hassan installed the unit and was a 100% correct. My house is 100% warmer, the hot water is so hot. He is a man who knows exactly what he is talking about. Please listen to him and trust him you won’t be making a mistake.

Aruna K.

Water heater

Sizing Your Household Water Needs

Tankless Water Heater Sizing Chart

Tank water heater sizing chart

1 to 1.5 Bathroom Home

2 to 2.5 Bathroom Home

3 to 3.5 Bathroom Home

Oakville, ON

Mississauga, ON

Brampton, ON

Richmond Hill, ON

Toronto, ON