Water Heater

Water heater Cleaning

It’s advisable to clean the water heater at least once a year to prevent sediment build-up. Otherwise, minerals will make it difficult for the burner to heat the water, worse, potentially clog the pipes. Spring is the best season to clean the water heater.

connect the hose to the drain valve and disconnect water line to prevent vacuum situation in the tank

shut off the valve (it is the cold water)

open the drain valve and take out all the water until the sediment comes out

Though you may have drained all of the water, lots of sediment should remain in the tank. Then you need to reconnect the water line and open the shut-off valve of the water heater. The water will drop from the top of the tank to the bottom of it. The force of the dropping water should make the sediment rise from the bottom, making it flow out of the drain valve.

Even after the above process, not all of the sediment will come out of the tank, but it should help take more sediment.

If your drain valve is plastic and old, there is a possibility of leaking after shutting the drain valve off. If so, you have to replace the drain valve.

No Hot Water

When there is no hot water, please check the burner and pilot. If there is no fire on the pilot, you need to change the thermal coupler. It usually is worn out after 3~4 years.

Combustion Air Requirment

Ordinarily, many people are installing the water heater at the garage. But sometimes, you need to install it inside of the house. If you have to install it inside the house, you have to consider sufficient fresh air.

Code requires two cubic feet of o2 to one cubic foot of the gas. So, for example, if the capacity of a gas water heater is 50,000BTU, need 2,500 cu ft of fresh air.

As you see in the picture, Code is requiring two of 100 sq. In. Net opening space for 40.000 BTU water heater.

Also, these open spaces should be within 12” from the top and the bottom.

So if you install 40 gallons gas water heater in a confined space, you need at least two of 125 sq. In. Net open space within 12” at the top and the bottom.

T&P Valve

A temperature and pressure relief valve (T&P valve) is required on all water heaters.

When the temperature is exceeded 210° F, the T&P valve will be opened and release the hot water to control the inside temperature.

However, this valve is consumable, and it would leak after 3~4 years.

If it is leaking, water will come out through the T&P valve drain pipe.

When it is leaking, you need to change it.

Water Heater Installation

take off the old straps.

Install new straps and 2″ thick wood space bar. (water heater needs 2″ gap from the wall) and set up the new water heater.

Installing a T&P valve drain. (3/4″ pipe)

Disconnect inlet and outlet pipe and draining all water in the tank with an opening drain valve at the lower side of the water heater.

Shut the gas valve off and disconnect the gas line. Now you can remove the old water heater.

Connecting hot and cold water lines with the flexible water lines, you need to install a valve at the cold water line side and join the vent pipe. Also, you need to tighten 2 of the straps.

This drawing is showing how to install a water heater in the garage

Tankless Water Heater

You need to consider the following points before installation.


  1. Check the capacity of the water heater.

    Sometimes if you are using more hot water than usual,

    you may need a bigger size than the standard capacity.

  1. You need a minimum 3/4″ gas pipe size.
  2. You need a vent pipe with a double stainless steel wall because of hot vent gas.