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Riello flame sensor

How would I go about testing a Riello RS 100 gas burner flame sensor? The burner is having intermittent ignition issues.




  • heatpro02920
    heatpro02920 Member Posts: 991
    edited March 2014
    Is it a UV probe, rod,?

    I have seen some rs's with a rod that runs opposite the electrode and others that had a UV probe kind of bolted to the left side of the fan housing pointing right...

    Last rs I had with an intermittent issue, drove me crazy for 3 days, I hate to admit it turned me into a parts changer, I first checked the entire burner out {looked great} and fired great while I was in front of it, so I changed the rod, next day, call came back, so I went back and checked it again, someone else already changed the electrode assembly so I reisntalled the old one, 3 hours later it came back, so I changed the air switch, it came back again BUT I got there and it wouldn't light, THANK GOD, found a bad gas pressure switch changed it and I put all the old parts back on and it never came back again...

    I hate them calls, someone needs to invent a camera that can watch the burner with a gauge and meter on each part, like a data logger with visual support...

    Anyway if its a rod, clean it, and test it like any other, I am not positive on where its supposed to be maye between 2.0 and 4.0 hot, you will have to call riello or check the manual...

    The rods are cheap $50 or so the photocell style is not at $300 or so...
  • haventseenenough
    haventseenenough Member Posts: 61

    Riello calls it an ionization rod, and as far as I can tell there is no way of testing it, or I just do not know how to test it. What do you mean by 2.0 to 4.0?


  • heatpro02920
    heatpro02920 Member Posts: 991
    If it were me..

    I would test everything in the burner, go through it and check it all out, make sure the switches are adjusted correctly, gas pressure is rite, relay is working, ect.. Time is money, cant go back 15 times...

    So if I came up with thinking it was the flame rod I would change it, after I cleaned it... You have an intermittent issue, so unless it does it in front of you its tough to pin point..

    To test a flame sensor-

    1- clean it and make sure its in the correct position...

    2- with a micro amp meter, connect the neg wire to the wire and the positive side to the sensors connector...

    3- start the unit as normal

    4- after the burner is lit you should get a reading {some units are different, but most look for between 2 and 4}..

    If its low or erratic change it.... Its a $40-50 part, not worth the fuel it takes to return...

    Hopefully I am explaining this correctly.... good luck..
  • haventseenenough
    haventseenenough Member Posts: 61

    heatpro, seeing as I am onsite at this building I did observe the burner fail. After gently sliding out the burner housing from the air tube I found that the sensor wire had come loose.

    Cleaned the sensor and reattached the wire securely and success.

    Thanks for your help/1
  • heatpro02920
    heatpro02920 Member Posts: 991
    good stuff...

    glad its fixed...
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