Tankless Water Heater Repairs [5 Easy Steps]

Tankless Water Heater Repairs

A tankless water heater is an efficient means of showering, doing laundry, and dishwashing among others.

A switch that is flow-activated is turned on. Then the heat exchanger turns on and heats your water as per your preference. This means that you don’t more energy to heat up your water since the tanks do not store the hot water in the tank.

Tankless water tanks just like the rest of your home items require maintenance either by daily care or once in a while repair.

Step by Step Guide for Tankless Water Heater Repairs

Step 1: Switch off the power supply

To relieve the water pressure, switch off the inlet and outlet water valves. Turn off the gas and ensure you unplug the electricity supply. You can also switch off the circuit breaker.

Flip the switch used to disconnect the subpanel on an electric unit to remove the cover in the unit section.

Step 2: Run Vinegar

Run vinegar down the sump pump suction using a pickup bucket. Ensure a horse is running down to the pump from the inlets of the water heater and another one from the relief valve. To allow for the vinegar to run well throughout the water for several minutes, ensure the pump is plugged in or turned on. If the pump is plugged in, the heating element is free from mineral deposits such as scaling.

The most common problem that may require repair is improper ventilation. The use of a standard -B vent happens to be the most common problem. The use of the standard B vent can cause damage to the heat exchanger due to acidic condensation.

Improper venting can cause gas leakages which are very risky. To prevent all these problems or repair the damage, the tankless water heaters should be sealed with approved stainless steel vents that have been approved for use from reliable appliance sources.

Since there is an excellent affinity to just use the existing gas line for hooking up, there can be gas supply problems. For this, it is necessary to follow the manual for installation so that there can be closer attention paid to the gas line section. Whether you will be using natural, liquid or propane gas make sure you have ordered the correct gas for the type of gas that you will be using.

Also, ensure that the BTU per hour rating is no minimum size.

Step 3: Check Input Filter

You need to check the input filter if the flow of the water from the heater is low. Make sure you check the filter for fragments by removing it. Release the hot pressure and then make sure the cold water supply is turned off. To give the flow the final touch, clean or replace the water filter and then recheck the water flow.

Since there is a connection between the hot and cold water supply, check the plumbing if there are fewer amounts of hot water or wavering in temperature. To check for a single handle faucet or a damaged seal, open either the hot water faucets or the pressure relief valve.

While doing this make sure that you have shut off the supply of cold water to the heater. If it so happens that there is still a supply of water even after the pipe has sapped, make sure the plumbing is fixed since this is caused by a cross-flow in there.

Step 4: Soften Hard Water

There are specific areas where water has high levels of calcium and magnesium; this is referred to as a hard water problem. Hard water is known to cause scaling to the heater system. Thus it must be softened for the maintenance of the tankless water heater. It is best that you treat the hard water with a descaling device or some other water softener.

Just make sure you take care of the heat exchanger. The osmosis process should not be reversed since it will cause damage to the heat exchanger.  To reduce the tankless heater problems and to lengthen its life, make sure you remove the minerals or otherwise keep them on hold.

Step 5: Temperature Regulation

If the heater temperature happens to have been set too high to access more hot water or the gas is too small, it might all be a cause for the wavering heat. The fluctuating temperature can be the cause of having the shower turned to the cold side too much. The variable temperature does not allow for the steady flow of enough hot water to the heater.

You should consider installing a direct water kit if wherever you are there in the presence of chemicals, dust, grease, or other unfavorable environmental conditions. The heater should be in areas where their sufficient clean air and clean space in short.

Since the tankless water heater should be installed in the fresh air with enough clean air, certain places should get a direct vent installed. The direct vent unit helps a lot in drawing its clean, sufficient air from outside. Some of these are industrial areas, beauty salons, and restaurants.

The recommended temperature for safety is between 122 or 125 degrees Celsius. You may also want to adjust the temperature to that which will suit someone who has sensitive skin or kids.


I hope you have some ideas for tankless water heater repairs. It is hard to find a tankless water heater having problems if you maintain it properly. But, if you note a change in the temperature or just lack of hot water, this calls for repairs. You can choose to hire a plumber to do the repairs for you or just take a go at it.

To prevent the buildup of slits in the tankless water unit, it is recommended to flush it after every six months this will prevent the low supply of water. If the tank has internal problems, a professional would be the finest option in this case. Also while doing the repairs, it is good to refer to the manual for safety.