How to Install a Tankless Hot Water Heater

Here are a few reasons why you should install a tankless water heater

Space-saving- When a tank water heater eats up spaces as large as 12 cubic feet or more. A tankless water heater is not bigger than a laptop; some are as small as pads. So the space solution it provides is hard to ignore. Especially for kitchen and small bathrooms, these are more than full with their sleek and neat looks; they are part of interior décor. You can use hot water for washing your major household items like juicers, blenders, and utensils.
Portability- Some tankless heaters have the feature of portability; just connect them with a water source and power source, and they will bring you hot water in the middle of a jungle. Can you imagine that with a tank water heater?!
Energy-saving- A tank water heater never really shuts off, even when on vacation. A tankless water heater, on the contrary, works only after sensing a required flow of water. Naturally, that translates into a lot of power-saving.
Lightweight- Tankless water heater weights were ten times less than the traditional water heater. This feature makes it much easier to install. Lightweight reduces the risk of an accident.
High capacity- Tankless water heaters let more than 2 or 3 faucets have hot water. Depending on the capacity number of faucets may increase. One must not fear finishing all water from the tank because it will seamlessly supply hot water as long as the flow sensor realizes a flow.
The alternative source of Energy- Tankless water heater can take electricity or gas as a power source. So if your home’s electric configuration does not comply with an electric tank water heater or you live in an off-grid area, you can choose a gas-fired tankless water heater.
Saves water- People far from the heater point need not let the faucet open for a long time to store hot water in a distant hot tank. So gallons of water are saved.
Safety- Tankless Water Heaters control the water temperature to exact Fahrenheit. Thus, it avoids the risk of scalding. Some heaters have an auto-turn-off feature for safety reasons. Some have child locks too. The exposure from dissolved toxic metals is also removed as there is no tank; there is no risk of such toxicity from high concentrations in the hot water tank.

Where to install tankless water heater?

When installing a tankless water heater, where to install it can vastly influence its performance; later, some things you need to consider before you decide on the place-

For the whole home, water heaters. The previous heater had already installed water pipes and gas lines, so installing a new one at the old place is logical. Gas lines may need to be changed if the new heater is gas-fired and has a significant BTU transfer rate.

If it is a gas-fired tankless water heater, venting requirements are crucial. The vent must be at least 3 feet from the operable window when vented through the wall.
If it is vented through the roof, a long enough vent must be installed. So basements are unsuitable for installing the water heater that needs ventilation through the roof.

For the point of use water heaters

For point-of-use water heaters, tank-less water heaters are best placed close to where the faucet would use the hot water. Being said, there are some dangerous areas where you better not install your electrical appliances like a water heater, for example-

Under the air condition line (water can drip into it)
Above or down the electric box (it can catch heat or fire)

Know about electric panel and house’s plumbing configuration (that will help future repair issues and water heater’s performance)
Know about local building codes. (In every installation manual, you will learn plenty about them, and knowing them is vital in making the right decision about installation location)

How to install a gas tankless water heater?

FIRSTLY REMOVE THE OLD WATER HEATER

Generally, people install the new gas tankless water heater in the same place as the old water heater. It is convenient as their water line and probably gas line (if the previous one was gas-fired) already exist. Then step by step, follow these processes as require-Turn off the power, then turn off both water and gas supply valves and power. Then, you need first to disconnect and then drain the old water heater.

INSTALL A NEW GAS LINE FOR THE WATER HEATER

Your existing gas line may need to install a tee and valve. To attach your old gas line to the new heater, you can use a flexible gas supply line. You need to run a new gas line from the tee to the point where the line can easily catch the new water heater.

INSTALL NEW WATER LINES FOR THE WATER HEATER

Use the copper pipe to attach new hot and cold water lines to the existing water lines. This new line will go into the water heater. To pipe securely in the wall, use hangers. They will hold the pipe against the wall. Also, this will make it easy to the insulation of pipe later. It is recommended to clean the pipes and connectors before soldering—this helps to remove oxidation. To soldering, you need to apply flux to the end of the pipe. Then you need to slip the pipe and connectors together. Start soldering by heating the copper with a torch.

BUILD UP THE FRAME OF THE WATER HEATER

Some water heaters are ready to be hung; some are better to mount on a platform. If you want to mount the tankless heater on the platform, you can build a platform with 2 x 4-inch pieces of lumber. You can mount the new tankless water heater 4 inches from the wall.

CONNECT WATER HEATER WITH GAS LINES

Follow the manufacturer’s instructions and connect the shut-off valve and sediment trap to the water heater. Now attach the gas supply line with the shut-off valve and connect the water supply line with the water heater. It is imperative to check for leaks; this can be done by bleeding the gas line. Then turn it off until installation is finished.

INSTALL THE VENT

DUAL VENTING OPTIONS IN RINNAI TANKLESS WATER HEATER

Installing the water heater’s vent is also a significant part of the whole installation process; more or less, they are identical, and a manual with the heater will guide your way through it.

TURN ON THE WATER HEATER

It is time for the last stage of turning on the water heater after taking all the trouble. Simply, you need to insulate the hot water pipe from the water heater. Turn on the gas and plug in the water heater. Of course, it is aligned with any further special instruction in the manual.

How to install an electric tankless hot water heater?

Find the amp required

To figure out amp read volt and watt in the unit’s label. Divide watt by volt, and you can get the amp.

Stress test

In the case of an electric water heater, much emphasis is given to the breaker’s capacity. So do the stress test of the main breaker. Generally, all amps have the highest power, up to 80% capacity. They stand fortifier-if your tankless unit needs a 50-60 amp breaker. You will need 60*1.20=72 amp breaker more than whatever is available nearer to that value in the market. So do the math and check if your existing breaker is powerful enough or needs a new one.

Check if the unit is heated and the manual.

If the unit is heated, you cannot install the unit.
Check for manual instruction.
Check in the electrical rating plate that shows voltage and wattage, or look at the product spec sheet. You should Consult a Tankless manual if it is available.
If the manual asks for using a licensed plumber electrician and says your warranty will be void if you do it another way, you should consult a professional and get things done by them.

Check inside for wire connections.

Check the manual and the unit to decide how many circuit breakers it may need. A tankless unit can need a 1-6 circuit breaker and wires connected to those terminals separately. So look for it and do it according to the manual.

Install some additional if required

The on-demand electric water heater cannot heat water as fast as gas heaters. Electric gas heaters use electricity to produce hot water. So to reduce energy consumption, you can add a tempering tank to pre-heat incoming cold water. This will keep the thermostat set low and reduce consumption. For recovering from lower water pressure, you can add low-flow showerheads. Beware if water moves too slowly through the pipe, flow sensor sensitive tank fewer units may not activate.

First, remove the existing heater.
Expose the pipes and mark the spot where to install the new heater.
Mount the tankless heater in the selected place.
Then with the compression fitting that came with the fixture, Install the water lines to the heater.
To remove air from the line, you need to open the main valve and let the water run for 2 minutes.
Check the electric codes for appropriate wire gauge and breaker size.
After completing the connection, turn on the breaker and look for the model-specific signs of standby mode.
Set the temperature to your choice and open the faucet to see if the heater is working.

How much to install a tankless hot water heater?

The cost of installing a tankless water heater varies based on manufacturers, gas-fuelled or electricity-driven, capacity, labor cost, types of equipment & your living region. Also, an electric Tankless water heater costs from $800 to $1400—and a tankless gas heater installation costs from $1800 to $2000. Without installation, the value of the Tankless electric heater is around $800 & the price of the gas-powered heater is about $1400.If you need to repair the wiring system of a whole house or need a very high-capacity tankless water heater, this overall cost will be more. Before going to market, you can set your initial budget based on this post. Since this is a hugely helpful machine, your invested money will be a good use for it.

What Size Tankless Water Heater Should You Buy?

I believe there is nothing wrong with wanting to save money by a bit of adjustment; however, this is not feasible when you determine the size of the tankless heater for your home. Under-sizing your tankless water heater to save money will eventually lose you and, most likely, in a cold shower.

Size determination depends on-

Temperature
Flow rate
Fuel or power source

Know your demand (Flow rate GMP)

Determine the number of appliances you plan to run by hot water. Ad up their flow rates; the sum is the flow rate you need from your tankless water heater. If the sum is too high and cannot match any tankless water heater on the market, a solution is to install low flow rate fixtures.

Know your desired temperature

If you subtract the inlet temperature of your water from the temperature you desire to achieve, you get the temperature rise you are looking for. i.e., your required temperature is 155 degrees, and your inlet water is 55 degrees. So the tankless water heater you need has to give a temperature rise of 100 degrees.

Type of tankless water heater

The same gas tankless water heater will heat faster than an electric tankless water heater, so keep that in mind when determining the size.

So this house with the overhead fixtures and flow rate needs a tankless water heater with 11.5 GPM at a rise of 70 degrees in max. This is extremely unlikely that all the fixtures will be used simultaneously. So you can add up flow rates of the maximum number of fixtures that can be used simultaneously, which will also help you determine the size.