Fundamentally, there are two basic questions to answer before diving into the details of “what to look for”?
- How much hot water do you use? Are your family’s hot water needs low, medium, or high demand? For example,
- For just 1 bathroom, a low-demand tankless with flow rate 4-5 gallons/minute will likely suffice.
- For two bathrooms, you may want a medium-demand tankless with flow rate of about 7 gallons/minute.
- For three plus bathrooms or a larger family, you likely need a high-demand tankless water heater with a flow rate of 10+ gallons/minute.
- What type of tankless water heater do you need, gas or electric? Typically, you will make the decision, gas or electric, based on the utilities available at your house and their cost.
Checklist to consider before purchasing a Tankless water heater:
- Note that the capacity for a tank water heater is the capacity of the storage tank in gallons (for example, 40 gallons). Whereas a tankless water heater is rated by the flow rate, i.e. gallons per minute (GPM) of hot water it can provide endlessly. Typically usage for:
- A shower is 1.5 to 3 GPM
- A bathroom or kitchen faucet is 2 to 3 GPM
- A dishwasher is 2 to 4 GPM
- A washing machine is 3 to 5 GPM
- Determine your hot water demand.
- Depends on the size and needs of your family or small business – how many hot water demands are you placing on your heater at once?
- Size your tankless water heater to meet your demand needs.
- Take into consideration the geographic region where you live as that effects the ambient water temperature aka the inlet water temperature. The colder the inlet water temperature, the less hot water you get at a given outlet temperature.
- Decide if you want to provide an “up-side” cushion of perhaps 50% for extreme use periods.
- Evaluate whether you want a gas (natural gas or propane) or electric tankless water heater.
- Check energy sources (and prices) available where you want to install the unit.
- Do you have natural gas piped to your house? If so, this will likely be your logical choice.
- Do you have other propane appliances? If so, propane may be your preferred choice.
- Do you have electrical service available or are you considering solar? If so, this may be the environmentally friendly choice.
- Determine the cost of each energy source (operational cost)?
- Typically, natural gas provides the lowest operational cost, but check your actual cost. (For example, electric power may be cheaper near large hydroelectric generation capability—such as the Pacific Northwest or the Tennessee Valley).
- Typically natural gas is less expensive than propane but may not be readily available at your home.
- In general, a gas tankless heater heats water more rapidly than electric tankless and reduces the cold water sandwich problem. Thus, tankless gas water heaters often are more suitable for high demand usage.
- Indoor or outdoor (tankless water heaters are designed either for indoor or outdoor installation).
- Indoor gas tankless water heaters will often require venting; typically electric tankless heaters will not require venting.
- Outdoor gas tankless water heaters typically have simplified venting.
- Make sure you choose the appropriate model for your requirements.
- The brands we recommend are all well respected and the particular models have outstanding reviews among purchasers. Limited warranties range from 10 years to Lifetime. In general, tankless hot water heaters are quite reliable.
- The Initial budget (buying and installing). Consider all of the following:
- Purchase price
- Typically, the purchase price of electric tankless is lower than gas tankless.
- Installation price (consult with a professional)
- Do you want a centralized or multi-point system (affects both purchase and installation costs)
- Consider the cost of bringing the energy source to where you install the unit.
- Certain gas heaters require venting, the cost of which may vary substantially.
- Operational cost (typically the operational costs of natural gas are lower than electricity)
- Consider and check any rebates and incentives available for the installation of these more efficient water heaters.
- Typically, payback of purchase and installation costs may be less than 2 years.
- Maintenance cost
- Typical maintenance cost for tankless water heaters is low. But if you have hard water, you should expect periodic maintenance to descale sediments.
- Compare the warrantees among models you are considering.
Summary: What is the best tankless water heater for you?
The best model is the model that meets your specific needs. First, evaluate your hot water needs, and identify the tankless water heater that has an appropriate flow rate. Then decide whether gas or electric best matches your needs. Proceed to determine which specific product options best match your budget.
Because of their features, reliability, and customer reviews, we have selected the top-rated tankless units to provide endless, instant, on-demand hot water:
For more information based on your specific needs, check out our review on:
