Tankless hot water systems offer an array of advantages, such as lower energy costs and hot water on demand. However, they can run into trouble. Here are a few common issues these water heaters run into and how to address them.
Your tankless water heater has a limit on how much water it can provide at one time. Now, this doesn't mean your water heater can't provide hot water on demand — it can. What's limited is your hot water tank's capacity for pumping out that water to multiple sources.
Your hot water tank will try to compensate by working its hardest to get hot water to all sources requesting hot water. When it gets to be too much, it'll trigger the water heater to stop working, resulting in no hot water for anyone.
To fix this, you'll have to reset your tankless water heater. Many tankless heating systems have a reset button. Simply push this button, and it should reset your water heater.
A tankless water heater can be especially susceptible to mineral build-up. When the water heats up in your tank, it forces the calcium to separate from the water and cling to the heater internally as scale.
To flush your tank, you'll need a five-gallon bucket, a pump, a washing machine hose set, and about three gallons of plain white vinegar. Turn off your hot and cold water at the flush valves. Turning these valves off prevent the vinegar from circulating through your house's water system.
Next, you'll open the flush faucets, starting with the cold and finishing with the hot faucet. Attach the first hose's end to the cold tap and the other end to the sump pump. You'll attach the other hose to the hot faucet and place it in the bucket. Once you've secured the hoses, fill the bucket with the three gallons of white vinegar and turn on the sump pump. The vinegar should feed in a loop from the boilers to the bucket and back around. Let the submersible pump run for at least an hour to remove all of the calcium sediment.
To prevent calcium deposits on your tank, you'll want to do this process about once per year. You'll want to flush your system more often if you have a large household or frequently use hot water.
These issues are two of the most common you'll run into when you use a tankless water heater system. If you're still experiencing problems with your tankless water heater, reach out to a plumber for further help, or for more information about water heater repair.