Why does my gas tankless water heater keep turning off?

One of the most common reasons that your tankless hot water stops working in the shower is because your current unit can’t supply enough hot water per minute. If you’re attempting to do the laundry, run the dishwasher, and shower at the same time, then you’re likely straining your on-demand water system’s capabilities.

Why does my tankless water heater turn off?





Most are caused by either: mineral deposits incorrect installation (usually improperly installed vents) blocked air supply or exhaust vent inadequate size of unit minimum flow rate set too high or too low lack of gas or electricity water pressure too high or too low misconception of how tankless water…

Why won’t my tankless water heater stay on?

Check the gas valve and ensure that it is open, and that you have paid your gas bill. Check all sensors, wiring fuses, and electrical components to ensure they have not burned out. Ensure there is no condensation or debris on the burners that may cause them to not ignite.

Why does my tankless water heater go cold during shower?

So to avoid damage to the heat exchanger (and to avoid scalding you with super hot water), your tankless unit will shut itself off, leaving you with cold water in the middle of your shower.

What is the most common problems with tankless water heaters?

Most Common Problems With Tankless Water Heaters

  • Overload. Every tankless water heater has a flow rate capacity that should give you a good idea of how much hot water can be used simultaneously. …
  • Cold Water Sandwich Effect. …
  • Mineral or Sediment Buildup. …
  • Flame or Ignition Failure.





Why does my water heater keep tripping?

Altogether, the answer to your question “why does your water heater keep tripping the breaker” is simple: you either have a faulty breaker, a bad heating element, or damaged wiring. With these anomalies, it is necessary for you to find out where the problem takes place.

Why does my Rinnai water heater keep turning off?

Electric Tankless Water Heater Keeps Shutting Off



It could be something as simple as a loose wire. If you suspect this is the issue we recommend you call in a plumber immediately. Check that the heater is getting electricity, gas and water. Check the filter to make sure that there’s no debris in it.

How do I know if my tankless water heater is bad?

Signs Your Tankless Water Heater System Needs Repairs

  1. A drop in hot water pressure. …
  2. Lukewarm water. …
  3. The water heater keeps shutting off. …
  4. Unusual behavior from other appliances. …
  5. Leaks.



Can cold weather affect tankless hot water heater?

Most indoor and outdoor tankless water heaters have built-in freeze protection against temporary winter temperatures ranging from -5 degrees Fahrenheit to -22 degrees Fahrenheit. This protection cannot withstand long term below freezing temperatures.

What does a flow sensor do on a tankless water heater?

A flow switch is used to detect the presence of water flow and turns on the system to heat the water. Whenever there is a hot water demand, a reed sensor within the tankless water heater identifies the demand and initiates the heating process.

What temp should a tankless water heater be set at?



You’ll want to shoot for 100-115 degrees Fahrenheit for your water to be heated. If your groundwater temperature is 60 degrees and you want your shower at 110 degrees, that’s going to be a 50-degree rise.

What’s the lifespan of a tankless water heater?

15 to 20 years

One of the most common questions asked by consumers about tankless water heaters is how long they will last. A tankless water heater can last anywhere from 15 to 20 years with proper maintenance and operation. In comparison, a standard tank water heater normally has a working life of 10 years or less.

What maintenance is needed on a tankless water heater?

The good news is that tankless water heaters don’t require much maintenance, either. A tankless system should be serviced as a part of the regular preventive maintenance that heating and cooling systems receive. Electric or gas components should be inspected.

Why am I not getting hot water from my Rinnai tankless water heater?



If you find you’re not getting the hot water you need, start by lowering the temperature setting on your tankless water heater by a couple of degrees. It’s counterintuitive, but it affects the hot/cold mix ratio and will activate the tankless water heater unit for lower-flow fixtures.

How do you check gas pressure on a tankless water heater?

Quote from the video:
Quote from Youtube video: Slide the rubber hose. Over that port once we are connected your manometer is on. We can open the gas valve. Let your gas pressure. Study.

How do you check a Rinnai tankless water heater Ignitor?

Verify igniter is working. Turn off gas valve feeding the appliance. Unplug igniter wire; hold the igniter wire with an insulated pair of pliers about a 1/4″ from a piece of metal. Cycle the unit to ensure you see a spark when unit is cycling.

How do you check a tankless water heater Ignitor?

Testing the igniter



Turn the gas supply to the water heater off. Unplug the igniter wire. Use the insulated pliers, hold the igniter wire, and ¼” from a metal part. Run the heater.

How do you clean a tankless water heater Ignitor?



Quote from the video:
Quote from Youtube video: On the right side of the burner in front here remove this little plate.

How do you clean the Rinnai igniter?

Quote from the video:
Quote from Youtube video: So looking into it the two flame sensors go to the left and the igniter goes down which then on the bottom. The two connectors go down and the igniter goes towards the right.