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  1. #1
    Join Date
    Jan 2005
    Posts
    76

    majestic dual thermopile issues

    I came across a problem with my own fireplace Majestic M#RFSDV34RFN dual thermopile input to a honeywell gas valve. I am looking for literature on the the control board on that gas valve, I first noticed the length of time it would take to open and light the main flame (slight delay) then it would bring the fan on then shut it off right away, ok so I check the thermopile readings #1 is at450mv(wires disconnected) #2 is at 350mv disconnected, I checked the terminals now that they are back hooked up again #1 is at about 380mv, #2 is at 250mv with main flame and fan on, what are the minimun mv readings required to maintain smooth operation, in the mean time I just swapped the leads between powerpiles and it runs great,but I suspect the powerpile with the lower out of the 2 readings is the problem,any thoughts

  2. #2
    Join Date
    Nov 2005
    Location
    London, Ontario, Canada
    Posts
    268
    I learned the hard way on that unit. If you think the valve is the problem , think again. I had good readings on both but 1 had an intermittent short in it and messed me up. Buy 2 new t-piles and replace them before thinking of the valve. Remember the t-piles are polarity sensitive on that valve.

  3. #3
    Join Date
    Jan 2005
    Posts
    447
    As per one of my previous posts , I believe Hearthman stated these systems require a min. of 500mv open circuit on both thermopiles and that they are polarity sensitve, white leads to white dots on terminals.

  4. #4
    Join Date
    Feb 2004
    Location
    Ontario
    Posts
    700

    Smile

    Do the simple thing first, make sure the pilot is clean and is properly adjusted. That may be all you need to bring the mv right up.
    Question authority!

  5. #5
    Join Date
    Jan 2006
    Location
    Ottawa
    Posts
    27
    Majestic has a tech support book which covers this valve in length I suggest gettting a hold of them for it. The book is in my work truck atm and am unable to remeber the title and such. It covers all the vavles and most problems. One thing though is the blinking light codes are pretty vague, have a hard time figuring it all out.

    I work with a tech that claims to have replaced all kinds of these valves gonna have to mention the polarity issue.

    I had one encounter which I told the customer unfortunately I had no replacement batteries in my truck but would still have to charge for the call out there (cleaned the bugger up nice).

    One side note though soaping this valve is very hazardus to the life of it they tell you to use a sniffer.

    I will try to post the name of the book on monday.

  6. #6
    Join Date
    Mar 2005
    Location
    Portland
    Posts
    177
    The RFN valve has a self diagnostic feature and will give you a flashing code when problems occur. both Thermopiles must read within 100 mv of each other. if you have one that is weaker the valve will malfunction. look for 3 flashes of the little red L.E.D ;light this will indicate a thermopile problem. replace both thermopiles at the same time. never replace only one. also be very carefull removing the pilot assy if you have the 1/8 inch pilot tube. it will break off at the brass ferrul very easily.

  7. #7
    Join Date
    Aug 2004
    Location
    S.E. Pa
    Posts
    6,191

    Cool Majestic book

    Korben wrote, "I will try to post the name of the book on monday."

    Gas Hearth Product Service Manual ??

  8. #8
    Join Date
    Mar 2005
    Location
    Portland
    Posts
    177
    I scanned a few pages of the book. hope this helps. Bob
    Attached Images Attached Images   

  9. #9
    Join Date
    Mar 2005
    Location
    Portland
    Posts
    177
    another page
    Attached Images Attached Images   

  10. #10
    Join Date
    Jan 2005
    Posts
    447
    heatermanbob, I tried printing off those 4 pages you posted, but they did not print very clear. Is this manual (book)avaliable somewhere online?

  11. #11
    Join Date
    Mar 2005
    Location
    Portland
    Posts
    177
    as far as i know it's only available from majestic, but i'd be happy to email you better pictures if you give me your email address

  12. #12
    Join Date
    Jan 2005
    Posts
    76
    thanks very much for the info everybody

  13. #13
    Hi Heatermanbob
    I just joined the forum. I'm looking at the pages above you were nice enough to post. I have a honeywell rv8310 in a Majestic DV360. The pages are very helpful. I have a pilot that won't stay lit and I have replaced the thermopiles which generate 690mv and 790mv and light the led on the valve (blinks normally) but as soon as I let up on the pilostat the pilot goes out. I'm getting ready to replace the valve but I see on page one of the four pages you posted it says "should the pilot drop out, there is a safety interlock on the valve which must be reset before the pilot can be re-lit". I don't see such a safety on the valve. Do you know where this is and how I'd reset that? Thanks. Ron

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