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Tankless water heaters offer a variety of benefits, ranging from energy efficiency and longer lifespan to lowered utility bills due to the fact that the units do not need to store gallons of water at a time. While the perks of owning a tankless water heater are plenty, there are still common issues that can arise due to continual use and normal wear and tear. While it can be frustrating to wake up to no hot water for your morning shower or worrisome when you hear an odd noise coming from the unit, the good news is that most problems are easy to diagnose and repair with the assistance of a professional Arlington, TX plumber. Read on to learn about the most common issues associated with tankless hot water heaters.
No Hot Water
A lack of hot water is one of the most common tankless water heater issues, and there are several reasons why this may occur. If the red flame rod on the gas burner does not create sparks when you turn it on, there may be a problem with the ignition. A closed shut-off valve may also lead to no hot water, and this can be easily remedied by opening the valve. During the colder months, no hot water coming from your tankless water heater may be due to frozen pipes, and this issue can often be fixed with the addition of an insulation jacket.
Water Running Too Hot
If your water is running too hot, the thermostat on your tankless water heater may be set too high. Lowering the temperature can usually remedy this problem. Blockages in the pipes or water filter may also lead to overly hot water, or it may be due to sediment buildup or a broken temperature sensor. If the water remains too hot after reducing the temperature, it’s always best to consult with an Arlington, TX plumber for proper assessment and repair.
Gas Burner on Tankless Water Heater Won’t Ignite
If the gas burner on your tankless water heater fails to ignite and there is no flame present, this could be due to an improperly installed ventilation system, or there may be excessive condensation that’s causing the flame to go out. The flame rod may also be loose or damaged, or the gas control valve could be open when it should be closed.
Low Water Pressure
If you’re getting low water pressure from your faucet or shower, this could be due to an obstruction in either the plumbing or filter, which should be assessed by a professional plumber. Low water pressure may also occur when multiple water applications are running at once, leading to a greater water draw. You may also want to check with your utility company to make sure the low water pressure isn’t due to an external source.
Fluctuating Water Temperatures/Cold Water Sandwich
If you get warm water when you first turn on the faucet that runs cold and then warm again, this issue is what is known as a cold water sandwich. This happens when hot water remains in the pipes after use, and it can occur for a number of reasons. Your gas line may not be sized correctly to correlate with the tankless water heater, or you may be looking at a damaged flow sensor or a plumbing crossover when hot and cold water mix together. Since there are several issues that lead to a cold water sandwich, it’s always best to consult with a plumber before attempting to fix the problem on your own.
If you’re hearing unusual noises such as banging or clunking coming from your water heater, there may be dirt or debris stuck in the fan, or a leak in the sealed combustion may be causing the gas combustion to become irregular, resulting in noise. Improper ventilation may also be the culprit.
Lukewarm to cool water coming from your faucets may be due to a failing or improperly sized gas valve, which should be checked out by a plumbing professional. Additional causes of lukewarm water include sediment buildup in the heat exchanger, which can inhibit the warm water flow. Buildup can be removed by descaling, but it’s important to enlist the services of a professional to prevent damage during the procedure. A clogged venting system may also prevent the water from heating properly, or a plumbing crossover may be causing the outgoing water temperature to decrease.
If you notice white smoke coming out of the exhaust vent, it is always best to contact a professional to ensure your safety and prevent additional damage. In most cases, white smoke is caused by exhaust gas temperatures that are warmer than the outside air, leading to an imbalance.
Plumbing Crossover Test
Since plumbing crossover can cause various issues, it’s a good idea to perform a plumbing crossover test. Simply shut off the cold water supply to the water heater, open the hot water taps, and wait approximately 10 minutes. If you’re still noticing cold water sandwiching or lower water pressure, this indicates a plumbing crossover problem that should be properly assessed by a professional.
Error Codes Can Provide Important Diagnostic Information
One easy way to determine the specific issues with your water heater is to check the error codes that pop up on the LCD screen that most units are designed with to signal if and when an issue occurs.
If you’re in need of assistance with troubleshooting or repair of your tankless water heater, contact Benjamin Franklin Plumbing. Family owned and operated, the plumbers of Benjamin Franklin are licensed and certified, and the company offers service calls seven days a week, as well as emergency services to accommodate your schedule. If you’re located in Arlington, TX, call 817-478-4119, and if you need assistance in the Fort Worth area, call 817-983-7876. You can also schedule an appointment via the company website’s online chat system.