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Hydrostat 3250 issues

slee
slee Member Posts: 3
edited November 2024 in Thermostats and Controls

I have a Weil McClain Ultra Oil 4 boiler with a Hydrostat 3250 controller.

It's been a long haul to get this boiler to work correctly since it was brand new 4 years ago, but we are close now.

Currently the only issue we're having, is that if the boiler sits for an extended period of time without the house calling for heat in either of the two zones, it seems like it struggles to fire back up. Not sure if it's because the breach temp maybe gets too low or what.

It is not being used with an indirect tankless domestic hot water system, however, we did set a low temp limit anyway (I believe 140) but doesn't seem to help. Max temp is currently set at 186.

It doesn't seem to be an issue of the boiler temp itself getting too low, because even if the boiler temp is 160F or more, if it hasn't run for an hour or two (it's currently in the 60s during the day here in NE PA) it will struggle to fire. When this happens if you "restart" it several times, it seems to warm up and then will run fine on it's own until the next time it sits idle.

Just not sure what to do next. Of course, as soon as it gets much colder outside (soon) this may be a non issue anyway, but, I feel like it should be able to handle this temp. range.

Any help you might provide would be greatly appreciated.

Comments

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,658

    Sounds like air is getting into the fuel line. that would make it fail to fire on the first try. but ut sounds like you may be resetting the primary control more than once to get it going properly. This is not recommended and could actually be hazardous

    When you indicated that you have problems since it was installed and your "are getting close now" indicates to me that the person(s) working on your system are not qualified or trained in hoe oil heating works. When properly adjusted, that is a pretty trouble free piece of equipment. Have you had more than one professional look at this? Usually the place where you purchase you oil has a service tech (or known one) that can help you to get it right.

    Who hac been doung all the troubleshooting?

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • slee
    slee Member Posts: 3

    I don't think it's air in the fuel, and in fact we just replaced the pump as well which seems to have actually made the difference.

    It seems like as long as it doesn't sit without running for an extended (an hour or two) period of time, it runs fine, smooth as silk. If it's cold enough that it is being asked for heat frequently, it hums along fine.

    As far as restarting it goes… well i only did it when it was recycling itself, and as i mentioned it seems like as soon as it "gets hot" again it runs fine.

    The person that has been doing the troubleshooting is a friend who has installed this same boiler (minus the newer genisys controller) in multiple homes including his own. Checking the exhaust with a meter shows nearly perfect combustion, but like I said if it sits without running, then it struggles til it gets warmed up again.

  • LRCCBJ
    LRCCBJ Member Posts: 657

    The person that has been doing the troubleshooting is a friend who has installed this same boiler (minus the newer genisys controller) in multiple homes including his own. Checking the exhaust with a meter shows nearly perfect combustion, but like I said if it sits without running, then it struggles til it gets warmed up again.

    This is your problem. The "friend" is not qualified to find the issue. Ed is likely correct and you have a certain amount of air that is entering the supply line which the pump and delivery system must get rid of to operate cleanly.

    Any air that enters the oil supply will create havoc with combustion, especially on one pipe systems.

    SuperTech
  • Jamie Hall
    Jamie Hall Member Posts: 25,173

    Another possibility is that in fact the draught isn't "just fine" and when the flue is cold it is far enough off that the burner won't fire. What does this boiler exhaust into?

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • slee
    slee Member Posts: 3

    The exhaust flows into a power vent with a barometric damper near the boiler. To be clear when it is cold and the boiler fires, it does light, but it "flutters violently" and flames out.

  • HVACNUT
    HVACNUT Member Posts: 6,433

    Beckett NX?

    Power vent, or Direct vent?

    Actual combustion numbers?

    Actual smoke reading?

    Actual draft readings? All at steady state so crank up the thermostats.

    Pump pressure at trial for ignition?

    Vacuum reading?

    One thing I CAN tell you without knowing the above information. Its not the Hydrostat.

    LRCCBJSuperTech
  • SuperTech
    SuperTech Member Posts: 2,492

    It sure sounds like a poorly setup power venter. What exactly are these "perfect" combustion numbers? Did your good buddy leave a printout of the combustion analysis results?