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.07 draft at burner problems

mikedo Member Posts: 155
in summer i installed a peerless pro boiler had it set up by an oil burner man (im a plumbing contractor) my burner guy has passed away. everything was fine till the last oil drop. it shut off on safety. i told the customer to call the oil company for a service call. they came out changed filter blew back lines new nozzle and it worked threw the night. then it kept shutting down on safety. new cad cell relay was put in. ran fine for a day and then started rumbling on shutdown really bad. oil company came back and claims draft is.07 at burner. and that is the problem. it has a draft regulator rc right before it enters the chimmney. im going to test the draft myself tomorrow. smoke pipe run is four feet. its a 50 year old chimney with a ceramic liner. any ideas what to look for when i go back tomorrow. thanks for any help


  • billtwocase
    billtwocase Member Posts: 2,385
    positive or negative draft?

    overfire or breech? need more info. Could be a bad fuel pump, or even just a strainer that is plugged. last cleaning done? What cad cell control was on it, and what did they replace it with?
  • Patchogue Phil_2
    Patchogue Phil_2 Member Posts: 304
    chimney blocked?

    Check the chimney for (partial) blockage?
  • mikedo
    mikedo Member Posts: 155
    draft problem

    negative draft. oil company wants to bring out a chimney man to look at it. i dont know what draft is before draft regulator im going down to check it mysel. never heard of a chimney with to much draftf
  • mikedo
    mikedo Member Posts: 155
    high draft

    well i went to the job broke out my 20 year old oil burner tools. turns out yes the draft is high .05 at the breech with a fully open rc. boiler is a peerless pro. but the real problem is a bad oil delay soleniod thats why the 7505 cad cell relay kept locking out and when they put the new digital one on it worked. the new relay eliminated the post and pre purge so the unit rumbles on shutdown. im going to put a new oil pump on and put the old cad cell to have the purges agian. i also put the .65 nozzle in they used the .85 nozzle i left on the job and it seemed noisier and reset the air shutters. five days of misery is over
  • World Plumber
    World Plumber Member Posts: 389
    Postive draft

    Are you saying positive draft? If they have been running on low fuel levels there is a tendency for the sludge to fall in and restrict the oil flow to the burner. The pump has to create high vacuum to get oil and the flame soots. Good chance the sections are blocked.

         Check the oil flow if it doesn't run full bore blow the lines back again, check the pump strainer, treat the tanks. You may need to brush down and clean the boiler. I have seen the off on reset, they push the reset, the unit fires right up then goes off sometime later. As the oil becomes harder for the pump to pull the pressure drops the flame gets black and sooty. Run for any length of time it will block the sections.  Sometimes we are unable to keep the lines clear and need to start pulling fuel from the top.

  • mikedo
    mikedo Member Posts: 155
    negative draft

    no its negative draft. i think the peerless triple pass runs at a positive draft at the burner thought. the oil company is afraid its pulling so hard the flame it getting sucked up
  • Big Ed_4
    Big Ed_4 Member Posts: 2,235
    Too Much Draft

    To drop the draft further then one draft regular can handle and second one may be needed ....
    I have enough experience to know , that I dont know it all
This discussion has been closed.