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Cleaver Brooks CB70 Troubleshooting

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nevele
nevele Member Posts: 30
in Oil Heating
Is anyone out there familiar with the CB70 cleaver brooks primary control. Its been obsolete for at least ten years but I need some advice on troubleshooting. thanks

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  • deadmansghost
    deadmansghost Member Posts: 32
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    I worked with the CB 70 years ago, what's your question?
  • nevele
    nevele Member Posts: 30
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    The boiler starts,30 second prepurge,10 sec low fire hold, fires up ,burns for five or ten seconds, flame goes out, fault code is F10 which means flame detected during 10 second low fire hold. There is no flame or spark or anything during that period . I reluctantly tried the primary control from the other boiler and it worked fine. So the problem is either with the infrared flame detector , the plugin program module or the CB70 itself.
    Do you know of any way to check the flame detector (red plugin box).I don't want to tamper with the other boiler in any way since it is maintaining the building with no problem. A new control would have to be wired in at a cost of around five thousand dollars so I want to make sure i've tried everything first. thanks for your reply
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,506
    edited March 2016
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    deadmansghost said:

    I worked with the CB 70 years ago, what's your question?

    Holy crap!...how old are you now

    steve
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,506
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    Have a gander
    steve
  • deadmansghost
    deadmansghost Member Posts: 32
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    LOL retired Steve.
  • nevele
    nevele Member Posts: 30
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    Thanks but I've seen this and it doesn't answer my question.
    Docfletcher
  • deadmansghost
    deadmansghost Member Posts: 32
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    Hi nevele,
    I was a tech with a Cleaver Brooks Agent years back when the CB70 came out. I broke open some old notes from a factory training session I attended, nothing in there about IR amplifier testing on the CB70 which if memory serves me was a special version of the BC7000 control.
    Steve has sent a copy of the manual above and I recommend following the checks as shown for fault code F10.
    In my opinion the FSG has had its operating life and the boiler
    requires upgrading to new controls.
  • Docfletcher
    Docfletcher Member Posts: 487
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    One CB70 in NJ on ebay with best offer. 30 day guarantee.
  • nevele
    nevele Member Posts: 30
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    The building may be closing later this year so the owner doesn't want the expense of a new control so we might have to keep our fingers crossed that the other boiler will do the job. I'll have a closer look at the pdf that steve suggested. thanks everybody
  • gennady
    gennady Member Posts: 839
    edited March 2016
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    Try to change amplifier only, red thing plugged into the controller. It is probably just a bad amplifier.
    If you are not lucky then controller itself is bad. Controller is manufactured by Honeywell. BC7000. You can get it at reasonable cost.
    Make sure it is right one. Pay attention to the letters and numbers at the end of the model number.

    https://customer.honeywell.com/resources/Techlit/TechLitDocuments/60-0000s/60-2529.pdf
    Gennady Tsakh
    Absolute Mechanical Co. Inc.
  • nevele
    nevele Member Posts: 30
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    I don't have a spare amplifier and they tell me they are also obsolete . I just thought somebody might know how to check it without having a spare to try. thanks
  • Docfletcher
    Docfletcher Member Posts: 487
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    I'm not in the trade, but can you take the amp from the working boiler and try it in the non working one?

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