Jet MAXI D125 User Manual (English)

Questions and Answers:

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Alexander MunozAug 20, 2025
What to do if the LOW PRESSURE fault is displayed and the pumps do not run on my Jet Heating System?
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  Jeffrey PriceAug 20, 2025
  If the LOW PRESSURE fault is showing and the pumps aren't running on your Jet Heating System, here's what might be happening: * The internal isolation valve within the unit could be closed. If so, open the internal isolation valve. * The system pressure might have dropped below the LOW PRESSURE set point. To fix this, increase system pressure using a filling loop, or enable the SYSTEM FILL option. * The SPC CONTROLLER option might be enabled. Try disabling the SPC CONTROLLER option. * The LOW PRESSURE set point might be too high. In this case, review the system specifications.
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Clayton HarrisonAug 22, 2025
Why is the HIGH PRESSURE fault displayed on my Jet MAXI D125?
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  Joyce LoganAug 22, 2025
  If a HIGH PRESSURE fault is displayed on your Jet Heating System, it could be due to several reasons: * The internal isolation valve within the unit is closed, so you should open it. * The system pressure has risen above the HIGH PRESSURE set point, so you should decrease system pressure using a suitable drain point. * The expansion vessel has failed or lost its pre-charge, so check the expansion vessel pre-charge and re-charge if necessary. * The expansion vessel is undersized, so review the expansion vessel selection. * The HIGH PRESSURE set point is too low, so review the system specifications.
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Kelsey BellAug 25, 2025
What causes the break tank to overfill in my Jet MAXI D125?
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  lschroederAug 25, 2025
  If the break tank in your Jet Heating System is overfilling, consider the following possible causes: * The wrong or no flow restrictor is installed in the float valve (mini and midi units only). Check the float valve flow restrictor selection (mini and midi units only). * The float valve position is set incorrectly. Set the float valve to its lowest possible position. * The float valve has failed. Replace the float valve. * A pump non-return valve has failed. Replace the non-return valve.
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rluceroAug 26, 2025
Why doesn't the pressure reading match the actual system pressure on my Jet MAXI D125 Heating System?
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  Kristy DeleonAug 26, 2025
  If the pressure reading on your Jet Heating System doesn't match the actual system pressure, consider these potential causes: * The internal isolation valve within the unit is closed. Open the internal isolation valve. * The SENSOR TYPE option is set incorrectly. Review the SENSOR TYPE setting. * A non-return valve has been installed between the unit and the system. Remove the non-return valve. * The pressure sensor has failed. Replace the pressure sensor.
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Charles Ruiz MDAug 28, 2025
Why does the pump repeatedly run in short bursts in my Jet Heating System?
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  Bradley FinleyAug 28, 2025
  If the pump in your Jet Heating System is repeatedly running in short bursts, here are a few possible reasons: * The internal isolation valve within the unit is partially closed. Fully open the internal isolation valve. * The restriction in the connecting pipe work is too great. Increase bore, reduce number of bends, or reduce length of connecting pipe work. * A pump non-return valve has failed. Replace non-return valve. * The expansion vessel has failed or lost its pre-charge. Check the expansion vessel pre-charge and re-charge if necessary. * The point of connection of the unit is too far away from the expansion vessel. Move unit/expansion vessel connection points closer together.
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ramosjacquelineAug 29, 2025
What does it mean when the LOW H20 fault is displayed on a Jet MAXI D125?
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  Jennifer MooreAug 29, 2025
  If the LOW H20 fault is displayed on your Jet Heating System, it could be due to: * The mains water supply to the unit has been isolated. Turn on the mains water supply. * The mains pressure is poor. The fault will clear once the break tank has been re-filled. * A non-standard electrical connection has been made into terminals 19 & 20. Remove all non-standard electrical connections. * The low water float switch has failed. Replace low water float switch. * The digital controller has failed. Replace digital controller.
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Amy GoldenAug 31, 2025
What does P1 and/or P2 FLOOD LIMIT mean on my Jet MAXI D125?
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  ajonesAug 31, 2025
  If P1 and/or P2 FLOOD LIMIT is displayed on your Jet Heating System, it could be due to these reasons: * A large amount of water has been lost from the system. Investigate cause. * The relevant pump is air-locked and not pumping water. Bleed the pump. * The unit is undersized for the system. Review unit selection. * The FLOOD LIMIT time is too short. Consult Wolseley.
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jacksonchristopherSep 2, 2025
What does ERROR 1 fault mean on my Jet MAXI D125 Heating System?
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  Ryan MaysSep 2, 2025
  If ERROR 1 fault is displayed on your Jet Heating System, this could be due to: * The SENSOR TYPE option is set incorrectly. Review SENSOR TYPE setting. * The pressure sensor has failed. Replace pressure sensor.
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Jennifer ParkSep 3, 2025
What does HIGH H20 fault mean on my Jet MAXI D125 Heating System?
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  Daniel ThomasSep 3, 2025
  If the HIGH H20 fault is displayed on your Jet Heating System, it could be caused by: * A non-standard electrical connection has been made into terminals 21 & 22. Remove all non-standard electrical connections. * The digital controller has failed. Replace digital controller.
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Kimberly LopezSep 5, 2025
What does P1 and/or P2 FAIL mean on my Jet MAXI D125?
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  Douglas ClaytonSep 5, 2025
  If P1 and/or P2 FAIL is displayed on your Jet Heating System, it might be because: * The PUMP TYPE option is set incorrectly. Review PUMP TYPE setting. * The relevant pump has failed. Replace pump.