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low voltage indication on our lochinvar knight boiler

GL Member Posts: 2
<span style="font-size:16pt"><strong>When we experience voltage blinks....the kind that make your clock radios start blinking 12:00....our boiler likes to give us a low voltage message.....it proceeds then to stop all need to heat water....if i shut power to the unit off, then turn it back on....it will say standby....then will operate normally once there is a call for heat.....i have had the boiler man over to no avail....any ideas freely accepted......george



  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
    Possible solutions...

    Dirty power is rough on all new solid state controls.

    You could install a UPS power supply that would avoid the brownouts.

    If that is too expensive, you could install a Graslin timer that would reset the power to the controls every so often by cycling the boiler off then back on again.

    You might also contact the factory and see if they have a possible solution for you.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Zman
    Zman Member Posts: 7,554
    Have you?

    Have you checked the voltage. Any meter will give you the voltage. I would also check the polarity and ground. Some meters will allow you to "log" over a period of time. I would also check for a flaky neutral connection on the boiler and the electrical panel. Bad neutrals can drive you nuts!

    Triangle tube  had a problem a while back with short power out flashes. They solved it with a delay relay that would wait a few minutes before restarting after a power loss. The problem was fixed with the MBCA 5 board upgrade.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Paul48
    Paul48 Member Posts: 4,469
    edited July 2012
    Power Bump

    I was thinking that a time delay relay would provide more time for a reboot. Split second bumps could also cause parameters to change.
  • SWEI
    SWEI Member Posts: 7,356
    power conditioning

    Be careful with putting boiler controls on a UPS.  Some of them are sensitive to the so-called "modified sinewave" power the majority of UPSes provide when running on battery.

    If the glitches are very short, a power conditioner might do the trick.  This is not a "surge protector" you get at the home center or a computer place, but a big heavy beast made of copper and iron which will actually condition 60 Hz power properly.  You can find Oneac CB or CC series units for next to nothing on eBay if you're patient.
  • CMadatMe
    CMadatMe Member Posts: 3,086
    Dedicated Circuit

    Boiler should be on its own dedicated circuit and its sounds like it's not. I'd head to the local radio shack or best buy and purchase a line condiitioner before you loose a board and have to fork out more cash then 5 line conditioners would cost.

    Boiler is telling you there's a problem so the problem needs to be addressed and fixed. I don't think fooling the boiler with some type of time delay is going to stop it from seeing voltage drops.
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • Plumdog_2
    Plumdog_2 Member Posts: 873
    The way it was explained to me.....

    An instantaneous (very short duration) power outage can leave the boiler control "confused"and it will lock out sometimes on random errors. The time delay re-start gives it time to "re-boot" and resume normal function. I placed a half-dozen or more of these in service on Prestige and Wiel-Mclain Ultra boilers, and they seem to work. They are just a timed-delay relay with a very heavy-duty enclosure that is near impossible to put your fingers inside. Around here (Colo.), we get a lot of instantaneous power outages, more lightning than Florida! I have used UPS devices also, but I wired them so they only backup the boiler control, while everything else (pumps and exterior controls) are still on regular power supply (or else your battery goes dead right away). Good Luck, I hope the engineers are making this stuff more robust because what they are now is delicate and unsuited for heating equipment! JMHO10
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    I have frequent short-term power interruptions.

    I have a W-M Ultra 3 boiler, and have had it for a little over three years. I have a UPS on all my computer stuff, but none on the boiler.

    I have frequent (every few days) power interruptions that are short (less than one second0. The boiler is on 24/7, though it does not run that much (domestic hot water only in the non heating seasons). I do have a whole-house surge protector in the main power panel that supplies the boiler on a dedicated circuit of its own.

    So far, it has not caused a hard lockout of the boiler. Am I lucky? Or has W-M fixed this problem?
  • Zman
    Zman Member Posts: 7,554
    This sounds..

    This sounds exactly like the problem Triangle Tube had with it's MBCA 3 controller. It may be the same controller on your boiler (I believe it was made by honeywell).

    The fix was to install a "delay on" relay on the power supply to the boiler. When the power flashes it would leave the power off for a minute then turn the power back on. It sounds like your controller is sensitive to brief outages.Perhaps it holds enough charge to think it is still powered, then shows the lockout error. I think this would solve the problem.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Paul48
    Paul48 Member Posts: 4,469

    the delay is not tricking the boiler. When this occurs, it has already been tricked(if you will).It just holds the power out longer than the instantaneous outage.It should be on a dedicated circuit, and I see nothing that tells me otherwise. Even if it is, the power is lost to the whole house, and all circuits are affected.
  • SWEI
    SWEI Member Posts: 7,356
    it sounds like

    Your boiler's control board has enough capacitance in its power supply to not be affected my a momentary interruption of supply current.
This discussion has been closed.