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Rinnai water heater continually running

My home has a Rinnai 2552 water heater. For the past several days it has been running almost continually. It has not done this before. There is no water running and it continues to keep coming on. It sounds to me like the air intake fan is what is running but every minute or so it does ignite for less than a second and the fan stays on. There are no error messages on the remote. When the water is turned on, it works normally. Every now and then it will turn off for a few minutes but for the most part it is running continually. When I turn the water inlet valve off the unit will stop running so I am thinking there is either a pressure or temperature issue – possibly related to the change in seasons where I live? I don’t know if these units come on after a pressure change, temperature change, water movement, or a combination of these?

Any advice is appreciated.

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The rinnai comes on when water starts flowing through the unit.

Posted on Apr 18, 2008

  • Scott Magill Apr 24, 2008

    Do you have a hot water circulation line? If so that will cause flow through your water heater. If not there probably a faucet that could be mixing hot and cold water through it. You can turn off valves to faucets and see which one it is



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