Unlike other major cities, NYC faces several constraints that make it harder to maintain hot water. It’s not just scathing winter frost that requires more from a water heater, but also the number of residential appliances demanding that water at the same time.
As outside temperatures drop, incoming water temperature also becomes colder. As a result, it may be harder for your water heater to reach and maintain your desired temperature.
Water usage habits are an important factor. Homes and multi-residential buildings use larger storage tanks, directly impacting how much hot water is used across a neighborhood or city. Before you install a tankless unit in your home, consider your heating needs and how a tankless heating system might help.
How NYC’s Cold Water Temperature Impacts Heaters
To understand how your water heater works (or why it struggles), let’s break down a few key concepts:
- Temperature Rise: The number of degrees your water heater needs to raise the water temperature. In NYC, incoming water is around 40 to 50°F in winter. To get a hot shower (around 120°F), your heater has to raise the water temperature by 70-80 degrees.
- Gallons Per Minute (GPM): The rate at which your heater produces hot water. The bigger the temperature rise your heater has to handle, the fewer gallons it can heat at once. So with freezing-cold NYC water, your heater works more slowly.
- Central Tank: If you live in an apartment building, you’re likely sharing a single large water heater with all your neighbors rather than having your own. Everyone draws from the same supply.
- NYC Winter Average: This is the typical temperature of water coming into buildings during the winter months. Knowing this number helps plumbers properly size and set up your water heater.
How It All Works Together:
Because NYC’s water comes in so cold (with such a high temperature rise), your water heater can only produce a limited amount of hot water per minute (low GPM). If you’re in an apartment building sharing a central tank with dozens of other units, that limited supply gets divided among everyone. This is why your shower goes cold when your neighbor does laundry, or why mornings are the worst time for hot water.
Want to find out your building’s exact water temperature? You can either use the city’s winter average or contact local plumbing masters like us at Boris Mechanical.
How GPM Influences the Size Tank You Need
Most tankless water heaters are sized by GPM. This metric tells you how much water you need at the time of heating, or the rate at which your tank can take in water entering the system.
If you’re a renter, you can count on these common appliances having a standard GPM across boroughs:
- Shower: 1.5–2.5 GPM
- Kitchen Faucet: 1–2 GPM
- Dishwasher: 1–2 GPM
- Washing Machine: 2–3 GPM
If multiple fixtures run at the same time, their combined GPM can quickly demand more water than your tank can heat, leaving you with cold water. Working with a Boris Mechanical LPM can help you understand your fixtures’ GPMs and determine the best-sized water heater for your home.
City-Approved Tankless Water Heater Types
Electric Tankless
One of the most preferred types of tankless water heaters across NYC, electric tankless water heaters are the easiest to get approved for. They naturally comply with the city’s electrical and plumbing codes.
At Boris Mechanical, we specialize in installing or upgrading your electrical tankless unit(s) whenever you need us. Just call, and we’ll quickly dispatch a team of local technicians to your residence. And if you need help getting your unit approved by the city, we can help you handle that too.
Gas-Fired Tankless
Unlike electrical units, gas-fired tankless heaters are heavily regulated in NYC. Why? They need a proper flue or vent system, something only a master plumber can verify.
In addition to having the necessary vent system, gas options need to be compliant with:
- NYC Fuel Gas Code
- Combustion Air Requirements
- Licensed Master Plumber Installation
Choosing The Right Tankless Water Heater Size
The size of your tankless water heater will depend on where you live, how large your space is, and how many people are using water-fueled appliances. Electric tankless units tend to be more compact than gas varieties, making them a suitable option for a household’s hot water supply.
Tankless models, especially electrical options, can determine temperature rise all by themselves and adjust the system’s flow rate to accommodate. We can help determine your residence’s peak usage and ensure optimal whole-house heating at Boris Mechanical.
When asking yourself, ‘What size tankless water heater do I need?’, start here:
Household Size
The number of units or rooms in your home will determine the size of the heater you need. For smaller apartments or studios, only 100 to 150 amp service is needed, while larger or whole apartment coverage will require between 200 and 400 amp services or panel upgrades.
Large homes often need a dedicated vented system to go with their tankless water heaters.
Appliance Number
Even if you have a smaller unit, you may still require a high flow if you have one or more water-fueled appliances running (especially at once). In these cases, a multi-system heater might be necessary rather than a single unit.
Homes or townhouses with larger floor space usually have more appliances to power. They can often require multiple units from the start.
Electrical Capacity
Last but not least, if you’re choosing a simple electrical heater as your main power source, you will need to consider the electrical capacity of your space. Large tanks need 150 to 200 amps alone, so it helps to consider what your building can handle.
Older units can take about 60-100 amps, while standard or modern apartments can accommodate larger amp quantities at 100 to 150. You may not be able to run multiple units together or house a large heater.
Tankless Water Heater Service Whenever You Need It
You don’t want it to be bathtime and not have any warm water for your toddler. You need ready-to-go hot water at all times, something a tankless unit can make possible.
If you’re not sure what size water heater you need, we’re happy to help.
Just call Boris Mechanical for master service all across New York City. Soon enough, you’ll be enjoying all-around hot water even during the cold season.
