What does your Sterilight ballast fault code mean? Well, unless it’s one of the following it’s likely that you’re reading the display upside down (Yes this happens over and over again) and that LEE is actually 337 days left on your countdown.



Your lamps 1 year lifespan has been spent, you will need to order a new lamp and reset the ballast to fix this code.

A2 – UV level alternating

Your lamps output has dropped below 50%. You will either need to clean your quartz sleeve with an acid based product, clean the sensor head or clean the window the sensor looks into. If all these fail, you will need to replace the lamp.

Low UV level

Either your unit is not powerful enough to treat the quality of the water running through it or once again, your quartz and sensor peripherals need cleaning. Water quality may need a test or retest to come to a conclusion on this. We usually find this happens the most when people go for a smaller unit than they need trying to save money, only to fail their water test later.

Blank LED display

Your unit is not plugged in or doesn’t have enough power being supplied. This is usually found out because the advice is to switch your unit off then back on again. If you have done this and the display is still blank, you have a faulty lamp and it needs replacing. On rare occasions, the internal fuse may have blown on your ballast rendering it useless. This is not replaceable and you will need a whole new ballast.

I can assure you, these are the only fault codes Viqua Sterilight units are programmed to show. You can ring me up and talk about how your one is not on this list but I will bust your different fault code theory.

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19 Responses to Sterilight ballast errors and fault codes

  1. usb sticks says:

    One beetle recognizes another.

  2. conderaze.li says:

    it’s the first time that I got chance to know those ballast,
    before i only know magnetic ballast and electronic ballast

  3. have a customer with a steralite u v and display shows E E E E
    have not found anything that can tell me what that error code means. If you have any info. let me know, thanks, Trey Austin
    Water Technology Company

    • Ryan says:

      That is not a recognised error code I’m afraid. This points to the ballast having an internal error and will need replacing. Depending on how old the equipment is, it may still have some degree of manufacturer warranty available. It’s valid for up to 5 years on ballasts.

  4. Teri Stephens says:

    What does error 0374 mean?. Our lamp went out, so we replaced it and now it’s still beeping and says 0374. After the lamp went out I suggested unplugging the unit, since it wasn’t working, anyhow, but my husband left it beeping for 5-6 days. When he replaced the bulb he said the unit was very hot. What’s wrong – is the fan out causing overheating? Is there a wiring problem or the bulb bad?? HELP!

    • Ryan says:

      Because this isn’t one of the standard error messages it doesn’t sound good I’m afraid. I would try a reset as outlined here http://www.uvo3.co.uk/blog/uv-water/how-to-reset-an-r-cansterilight-ballast/ typically this will either solve your problem (the ballasts can get confused sometimes) or confirm you have a fault. Sterilight have a 5 year pro rata warranty that I’m sure applies to ballasts, so if you get in touch with whoever supplied the unit with your serial number to hand, they should be able to supply a new one that has the cost covered to some degree.

  5. MICHAE says:

    i HAVE a3 showing and understand lamp requires replacement how do I reset the ballast. Any help would be greatly appreciated

  6. Amber says:

    A3 code but we have new bulb in. At first we thought it was a faulty bulb so we ordered a second one and it’s still throwing that code

    • Ryan says:


      This will almost definitely be because one or more of the pins on your lamp aren’t making contact with the pin receivers in the connector cap. Do a quick visual check of the cap and make sure the pin holes aren’t either rusted up (easy to fix) or bent at some obscure angle (more difficult to deal with). Once you can see the problem, the solution should become apparent. Give us a call if you need any help though.

  7. Daniel says:

    How about error code 0t??

    • Ryan says:

      Hi there,

      An error code of 0t isn’t a recognised fault code. If the reset process hasn’t remedied the problem then I’d recommend talking to the people the unit came from to see where you stand. It doesn’t sound right though.

  8. jj says:

    my counter is reading 376 and climbing it is also throwing A-3 code I have cleaned pins and found no problems unit will not reset.

    • Ryan says:


      The A3 fault code is the one for ‘lamp life expired’ so I’m not surprised it’s showing that if you’re unable to reset it. If you can’t get the reset button to engage then if it’s still within warranty then I would ask your supplier to have a look at it. If they can’t then you will looking at replacing the whole thing as the button is not a repairable part.

  9. salim says:

    My Electronic controller showing A3 fault. I changed Bulb & try to reset but still A3 error not going. I replaced controller with new & its working good. Again i replaced bulb & fix old bulb in stand of new bulb. The new controller still working good.
    So what is the exact problem of my controller which is showing error A3 ?

    • Ryan says:

      I would say that there’s a connection fault either in the wire or through the lamp pin receivers in the end of the lamp lead. They will be in contact through some residue from the wires leaking out at high temperature.

      Alternatively you could have some build up on the pin receivers and need to clean them up a bit. They are often a problem on older units.

  10. salim says:

    The controller model is as below…
    “VIQUA model- BA-ICE-CM”

    • Ryan says:

      That controller is for a Viqua Colbalt unit that’s used with a UV sensor (the M stands for monitored)

  11. George says:

    I changed my bulb and got all the correct displays on the controller then the next day it started beeping so I reset the controller again and the reset was faint on the display and the 365 was faint and only came on for a second then the screen went blank. Did a couple of more resets with the same results. Is it the controller that is bad, it has only been 3 years since the unit was installed. What is the life of a controller?

    • Ryan says:

      I would actually say that it sounds like your lamp has failed. That’s what it would usually mean. The life of a controller is around 10 years, 15 if you’re lucky. They come with 2 years warranty on them so it’s out of that but it sounds like it may not be the problem anyway.