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I have a one zone single pipe-steam heating oil system with a
Lux PSP 511 La thermostat, I see that when the inside temperature
drops below the thermostat setting it takes time for the boiler to
turn on. My question is, "How long should it take for boiler to
turn on when temperature dips below thermostat setting".


  • Jamie Hall
    Jamie Hall Member Posts: 21,105
    That thermostat has a "swing" setting (check your user's manual) which affects how much below the setpoint the actual temperature goes before the thermostat really calls for heat. You could try changing that. The user's manual suggests 3 to 6 cycles per hour for heat -- which is not correct for steam. 1 or 2 is what you need for steam.

    The other question, though, is whether the time to which you are referring is a matter of a minute or so, in which case it may be a built in delay in either the thermostat or the burner Unfortunately, it does not appear that that thermostat has an indicator telling you when it is actually calling for heat...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • heatinghelpfor3
    heatinghelpfor3 Member Posts: 17
    Thank you for all your help, I am new at this, I am
    taking over boiler responsibility for my elderly parents and I have a lot of questions and a lot to learn.