To Next PageTo Next PageWhy does the pump persistently become air-locked in my Jet MAXI D125 Heating System?
If the pump in your Jet Heating System keeps becoming air-locked, it could be because the wrong or no flow restrictor is installed in the float valve (mini and midi units only). Check float valve flow restrictor selection (mini and midi units only).
Why is the HIGH PRESSURE fault displayed on my Jet MAXI D125?
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.
What causes the break tank to overfill in my Jet MAXI D125?
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.
Why doesn't the pressure reading match the actual system pressure on my Jet MAXI D125 Heating System?
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.
Why does the pump repeatedly run in short bursts in my Jet Heating System?
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.
What does it mean when the LOW H20 fault is displayed on a Jet MAXI D125?
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.
What does SERVICE displayed on the screen mean for my Jet MAXI D125 Heating System?
If SERVICE is displayed on the screen of your Jet Heating System, the unit is due an annual service. Contact service engineer.
What to do if P2 FAIL is displayed on a single pump Jet MAXI D125?
If P2 FAIL is displayed on your Jet Heating System, but it's a single pump model, the PUMPS NUMBER option is likely incorrectly set to 2. Change the PUMPS NUMBER setting to 1.
What should I do if the pump runs but doesn't make up pressure in my Jet MAXI D125?
If the pump runs but doesn't build pressure in your Jet Heating System, it's likely that the pump is air-locked and not pumping water. Bleed the pump to resolve this.
What does P1 and/or P2 FAIL mean on my Jet MAXI D125?
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.
General| Brand | Jet |
|---|---|
| Model | MAXI D125 |
| Category | Heating System |
| Language | English |
Details electrical connection requirements, safety, and isolation for the unit.
Lists essential conditions to verify before starting the commissioning process.
Explains how to access and modify controller settings using access codes.
Details all menu items, their functions, and default values for configuration.
Procedure to test the unit's operation by simulating a minor pressure leak.
Lists and explains all fault codes displayed by the digital controller.
Addresses issues when the LOW PRESSURE fault is displayed and pumps do not run.
Addresses issues when the HIGH PRESSURE fault is displayed.
Addresses issues when P1 or P2 FLOOD LIMIT faults are displayed.
Addresses issues when P1 or P2 FAIL faults are displayed.
Addresses issues related to low or high water level faults.
Addresses issues with pressure readings and sensor errors.
Addresses pumps not making pressure or becoming air-locked.
