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Rinnai tankless heater stops working after it rains?!

Mr_Beal Member Posts: 2
hi, I have had multiple useless service technician​s to my house and my land lord has spent over three grand on trying to get the problem worked out. after any rain, my rinnai spits error 61, the fan assembly has been replaced once, the techs have simply said nothing is wrong, but obviously something is wrong. do you have ANY little idea as to why it would stop working after it rains? thanks for littlerally any light you can shine on the situation.

this is the video I took of what it does when I try to use hot water https://youtu.be/ZQSBS9tQ0sU

This has been an ongoing issue for at least a year. So needless to say any ideas are awesome!!!!


  • Jamie Hall
    Jamie Hall Member Posts: 23,456
    How does the rain get into the intake or the exhaust or both?
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Mr_Beal
    Mr_Beal Member Posts: 2
    The pvc vent that runs from the top of the machine through the foundation to outside is the only way I could see water getting into the machine.
  • Gordy
    Gordy Member Posts: 9,546
    edited May 2017
    Pic of intake, and exhaust terminations outside to rule out improper venting.

    Edit: is the combustion fan proven defective? Or is it just replaced because the 61 code?
  • Gordy
    Gordy Member Posts: 9,546
    If the intake run is short, and an improper intake termination possible it sucks enough moisture into the fan. However when replaced was there moisture in the venting.
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,239
    I would also take a look at the power supply. If you have an underground electric service coming into the house, and the wire is compromised, you can get faulty, unstable current in your house. The reason it would create symptoms when it rains, is that the soil becomes more conductive when it is wet and would strengthen the electrical short.
    A good electrician would be able to diagnose that for you. I won't post details on the diagnostics procedure because they are dangerous and should only be done by an experienced electrician.

    If you getting water directly into the unit, it should leave some evidence of such.

    Also, the vents on the gas regulators should be checked. If the are oriented such that they could collect water, that could cause a problem with gas pressure.
  • cougar11
    cougar11 Member Posts: 1
    edited May 2020
    Hello, mine does the same thing but it’s a different code. I will do my best to describe but I don’t have knowledge of all the parts within the system. My Rinnai will pool water at the bottom of the housing if the hot water is running WHILE it’s raining or there’s moisture in the air. When it occurs I hear a beeping noise, go to the system on the wall, it reads 79 so, I unplug it while I dry out the bottom of the housing with towels and an air can or blow dryer. Once it’s dry, I plug it in and it works like a charm until the next time it rains AND is in use. My vent runs horizontally. It seems that there’s condensation further inside the system but I don’t know where to look for a fan. I notice that water drips from a pin hole below the component that houses the flames. My dad is a plumber 30+ years and he was convinced that it was just a looped condensation line that was missing. We added that and still it happens but only when it rains/moisture and being used. If it’s not raining it works fine. Thoughts? Suggestions?
  • warriorrob3
    warriorrob3 Member Posts: 1
    Cougar 11, SAME with my unit....I wish Rinnai would help, the phone customer service is horrible, and professional plumbers need to see it while its happening, otherwise they are no help and costly. Simple has water everytime I get a bad rain storm....