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OLD System, Help

Hello Everyone,

So here is what I am currently working with. I know this system NEEDS replacing but i need to get thru at least this winter with it. Any and all help would be greatly appreciated.

I have an oil powered boiler for heat only thats old, very old probably from the 60's (and thats high hopes). The boiler is gravity fed (no circulators), connected to 12 cast iron radiators. Boiler is powered by a Beckett - af series I think.

Tstat was calling for heat, beckett would turn on but no ignition. Fuel flow was present. After troubleshooting electrodes were extremely worn down and nozzle was partially clogged.

Replaced the nozzle and replaced the electrodes, had to adjust distances multiple times till finally got ignition.

Closed everything up hit the reset button, lit up immediately. Felt great, I fixed it.........or so I thought.

House was warming up getting nice and cozy, then the boiler turns off after only an hour or so while Tstat still calling for heat, waited another hour or so went to check it out and had to hit the reset button and this time....no ignition.

So I checked the transformer via insulated screwdriver method (when checked earlier appeared to be good) and now barely any spark what so ever. So I plan on replacing the transformer tomorrow morning. Hopefully that solves problem # 1.

Here comes the next part, so in replacing the nozzle with a nice new clean nozzle I noticed the flame is much brighter. Which in turn i assume is due to increased oil flow and therefore burning hotter. The temp shut off is set to around 140*F. Now the boiler is reaching the 140*F Mark and shutting down before all the radiators get hot. Again I am assuming this is due to the new clean flowing nozzle. With the old nozzle the system would pretty much run for hours and hours and rarely shut down. Now it lasted only around an hour before shutting down.

Should I increase the temp shut off setting? If so what is a good temp (I've been reading 180*F on here)?

Should I go down a size or two in nozzle? (Currently using a 1.00 80 A)

Should I do a combination of both?

Again sorry for long post but I want to give as much info as I can think of. Any and all help will be greatly appreciated.


  • Steamhead
    Steamhead Member Posts: 15,991
    What model boiler is it?

    Where are you located?
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,132
    You need an oil tech. Most of your assumptions and methods are incorrect.
    Changing a nozzle requires a combustion test.
    You can’t tell if a nozzle has partial flow. If your nozzle is clogging, your fuel filter and pump strainer should be changed, possibly a fuel issue needs to be addressed.
    Screwdriver test isn’t the only way to check a transformer.
    Electrodes need pretty precise settings, just off a 1/16” on any of the 3 settings could mean the difference in lighting off the oil and not.
    The brightness of a flame has to do with the air adjustment which must be done with proper instruments.
    Gravity system requires hotter water to get better flow thru the system.
    Changing nozzles and guessing is a fools errand.
    You’re in over your head.
  • @Steamhead - Long Island NY, I will see if there are any markings on it tomorrow when i get back.

    @STEVEusaPA - No doubt on needing an oil tech I agree, I need to find someone I can trust. I replaced the nozzle with the same type I took off. So didnt change any nozzle sizes. None of the air openings were adjusted. Maybe its just an illusion or in my head about being brighter. Tomorrow i am going to replace transformer anyway. As for the water temp, what is a good area?
    HVACNUT Member Posts: 5,026
    Nozzles can be + or - 10% from the stamped rating. That's why combustion, smoke, and draft tests MUST be done.
    Sounds like you're getting COD oil deliveries. You need a full service agreement with a reputable contractor. Pay more for fuel but you gain piece of mind.
    I'd think 180° for a gravity system. Not too sure though. I haven't seen one in forever and a day.
  • @HVACNUT you are correct. COD. I think I might just do that. Seems that saving a buck with COD had its drawbacks. Thanks for the info
  • Jellis
    Jellis Member Posts: 228
    I agree with other posters, get a tech in there ASAP with proper equipment, as mentioned the electrodes need to be precisely spaced and you need to do a combustion test to dial in the unit. Otherwise you are surely sending money up the chimney by your unit not being set up for optimal efficiency and possibly creating a situation that could be dangerous, like a plugged boiler.
  • @Jellis I have a boiler tech coming either tomorrow or saturday to check it all out. This boiler is so old I dont think the word efficiency existed yet lol.

    On another note I replaced the ancient transformer with a new one and it is purring like a kitten.

    Also I took electodes out and properly spaced them.

    Thanks everyone for your respnoses.