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Discuss Help.. Intermittent oil boiler lock out ( moved from Central heating Thread) in the Oil and Solid Fuel Forum area at UKPlumbersForums.co.uk.

  1. RayPlumb

    RayPlumb Member

    Help .. Running out of options..
    I have a client with a Grant vortex utility system 36-46 with riello burner.
    There is about a 20metre 10mm oil line under ground from tank to a fire valve (vertical? ) then tigerloop, Then in through a 22mm duct into the property under passage about 2.5mts then into boiler room out behind an unvented cylinder round into back of boiler. 2 Pipe then back to tiger loop.
    Flue is balanced flue straight up +/- 2mtrs through ceiling-roof
    It started locking out every few days last autum. I services it and changed dirty bowl filter.
    Went for a few days then locked out. I had a look and changed a stiff boiler temp control button and was fine all summer.
    Then a few weeks ago started locking out again. They always reset it by the time i got there and it seemed to run like a dream while I was there. Checked combustion, fan movement, oil supply etc. about 2 weeks ago went out locked out and smell of oil - cracked top of tigerloop?
    I then changed the tigerloop, flushed oil line ( few bits of sludge). Changed pump, drive dog and capacitor. Checked photo cell..
    All ran fine for a week then this morning locked out again. Going back tomorrow to have another look.
    I had a suspicion about the fire valve being vertical and no filter just before it. Problem is there is no room to install a filter where it comes out ground and to make fire valve horizontal.
    What is the affects of a vertically installed fire valve.
    Any Suggestions where to check next.?
    Is it only a fault in the burner that can cause a burner lock out?
    If there was a thermostat fault could that cause lock out or just over heat stat...?
    or poor flow through system...?
    Any suggestion welcome
  2. SimonG

    SimonG Plumber

    Heldite all the oil line joints.
  3. Best

    Best Trusted Plumber Top Contributor!!

    Don't waste your time and materials just changing parts.
    If a burner locks out, then the fault is to do with the burner, or its oil supply or fuel/air setting.
    A firevalve fitted vertical is totally fine.
    The oil pipe diameter needs to be not too big for Tigerloop and with no high spots and definitely no leaks. The suction hose could allow air in if jointed bad.
    Get an oil engineer to look at it. Too high an air setting will make boiler not start on cold weather first starts.
    • Like Like x 1
    Last edited: Dec 6, 2016
  4. Dotty

    Dotty Guest

    Wonderful stuff, heldite. ..
  5. RayPlumb

    RayPlumb Member

    What do you mean oil pipe diameter needs to be too big for tigerloop?
    Unfortunately most of the oil line form tank to tigerloop is under concrete
  6. RayPlumb

    RayPlumb Member

    Burner settings are O2 - 5.6%, Co2 - 11.3% , Co ppm - 27 , Xair - 36.6%

    So should I suspect air getting in suction hose or pipework form tigerloop. Presume any air being sucked in on oil line from tank will be vented through tiger loop?
  7. Chalked

    Chalked Plumber GSR

    • Like Like x 1
  8. Best

    Best Trusted Plumber Top Contributor!!

    No, my wording was diameter needs to be NOT too big.
    Your analyser readings are good, so it could be air getting into oil line, or very possibly the capacitor as Chalked mentioned. Check the burner motor/fan starts instantly and try the burner on and off a dozen times to test motor always starts instantly. Any split second start will show capacitor faulty.
  9. RayPlumb

    RayPlumb Member

  10. mache

    mache Member

    If capacitor is OK then solenoid could be on it's way out. OK when cold but degrading when warmed up and cutting off oil feed.
  11. RayPlumb

    RayPlumb Member

    I changed solenoid with one I knew worked. Day later locked out. Tested both and got 100 and 101ohms.

    Trying to work out if suction pipe sizing is correct.. I have 20- 25mts of 10mm copper pipe from oil tank to tigerloop. If pipework was forming gas and air in the pipe run would it not vent at the tigerloop ?

    The boiler nozzle capacity is 4.5kg/h
    Boiler is set at 41kw
    Last edited: Dec 7, 2016
  12. RayPlumb

    RayPlumb Member

    Bottom of tank and tigerloop same height and burner down about 0.5mts
  13. SimonG

    SimonG Plumber

    Remove tigerloop and change back to 1 piper. Had to do that to one week before last. Been fitted on a eaga job. Didn't need tigerloop and compression fittings everywhere.
  14. RayPlumb

    RayPlumb Member

    I considered that but MI says max pipe run for 0.5m head is 10mtrs @10mm and I have a 25metre run, Even if I upped it to 12mm that would only give me 20mtrs, Although should be fine when tank full..
  15. RayPlumb

    RayPlumb Member

    Just back from the boiler. .. Checked all joints that I could access.
    Correct me if I have done this wrong...(Two Pipe system) I put a vacuum gauge on the pump and fired boiler, It read 0 vacuum pressure??.
    I then isolated the fuel at the tank and pressure dropped to -.05bar. I then switched the boiler off and the pressure held. I left it for about 30 min and only lost a fraction -.005bar.
    Opened the tank isolation valve and went back to 0.
    From this can I presume I have pressure tested all of the fuel line suction and return to tigerloop. ?? And they are OK..?
  16. RayPlumb

    RayPlumb Member

    Sorry Pressures are supposed to be -0.5bar at vacuum test. Cant read my own notes
  17. lame plumber

    lame plumber Plumber GSR

    hate to say it but a pressure test means you apply pressure to the line and look for a drop over time