To Next PageTo Next PageHow to reset Dometic Qht when 'Ar / FL' is flashing?
If 'Ar / FL' is flashing on your Dometic Control Unit (Filter Reminder), clean or replace the filter. Reset and stop the flashing by pressing the FAN, UP, and DOWN buttons simultaneously.
How to troubleshoot Dometic Control Unit that will not start?
If your Dometic Control Unit system won't start, try the following: 1. Ensure the air conditioner circuit breaker is on at the ship’s panel. 2. Make sure the digital control is turned on by pressing the Power button. 3. Check the wiring at the terminal strip against the wiring diagram and correct if necessary. 4. Verify the input-line voltage is sufficient by checking the power source for proper voltage and inspecting wiring/terminals. Use a voltmeter to confirm the power at the unit matches the power source. 5. Inspect push-on connectors or butt splices for disconnections; disconnect the power supply and open the electric box, check wiring diagram, and correct if needed.
Why does my Dometic Qht system run continuously?
If your Dometic Control Unit system runs continuously, it might be due to the following causes: * The set point temperature is improperly set. Raise or lower the set point. * Make sure all port holes and hatches are closed. * The air sensor location might be incorrect. Verify the air sensor location with criteria found in the control manual.
How to fix low airflow in Dometic Qht?
To address low airflow in your Dometic Control Unit, try the following: * Remove any obstructions in the return-air stream. * Clean the return-air filter and grille. * Check for crushed or restricted ducting, ensuring it is as straight, smooth, and taut as possible. * If the fan speed is set to manual low, press and release the Fan button until the desired fan speed and airflow are reached. * For automatic fan speed control, press and release the Fan button until the letter “A” displays.
What to do if Dometic Qht Control Unit fan coil is iced?
If the fan coil in your Dometic Control Unit is iced, consider the following: * Raise the thermostat set point if it's too low. * Remove any obstructions in the return air stream and clean the return air filter and grille. * Check for crushed or restricted ducting, ensuring it is straight, smooth, and taut. * Redirect supply air so that it is not blowing into the return air stream. * Seal any air leaks on the duct. * Close hatches and doors. * Switch the air conditioning unit to heat until the ice melts, or use a hair dryer to melt it.
How to troubleshoot Dometic Qht Control Unit when digital display panel is not lit?
If the digital display panel of your Dometic Control Unit is not lit: * Turn the circuit breaker on. * Ensure the control is connected to a Q-Logic or U-Board, as it will not work with an SMXII Power Board. Replace with Q-Logic or U-Board if necessary. * Replace CXP or TSEP cables if necessary. * As a last resort, replace the control, Q-Logic, or U-Board.
Why is the Dometic Qht temperature display erratic?
If your Dometic Control Unit's temperature display is erratic: * Try shutting the power to the unit off and then back on. * Perform a Restore Factory Settings. * Check the sensor cable and connections. * Ensure the temperature sensor is installed properly. * Calibrate the temperature. * Replace the Q-Logic or U-Board.
How to fix erratic system operation of Dometic Qht Control Unit?
To address erratic system operation in your Dometic Control Unit: * Shut the power to the unit off and back on. * Check the CXP cable and connections. * Check the temperature sensor, cable, and connections. * Replace the control. * Replace the Q-Logic or U-Board.
Why does the fan run continuously on my Dometic Qht Control Unit even when set to cycle with the compressor?
If the fan runs continuously on your Dometic Control Unit, even when set to cycle with the compressor, it may indicate a failed triac on the circuit board. Consider sending it for repair or calling a local service technician.
How to increase duration of Anti-Icing Routine on Dometic Qht?
To increase the duration of the Anti-Icing Routine on your Dometic Control Unit, change Programmable Function 21.
General| Brand | Dometic |
|---|---|
| Model | Qht |
| Category | Control Unit |
| Language | English |
Contains essential information for operating the control system; keep for future reference.
Describes the two different controls, Q3 and Qht, for operating the system.
Lists standard and optional features of the Q3 and Qht controls.
Explains the basic principle of air conditioning and heat transfer in marine systems.
Details how seawater temperature affects system efficiency and capacity.
Details the layout and function of the Q3 control display panel and its indicators.
Provides critical notes for installers and end-users regarding programming and system setup.
Instructions for physically mounting the Q3 and Qht display panels on a control surface.
Guidelines for properly installing ambient and seawater temperature sensors for accurate readings.
Explains the available operating modes like Cool, Heat, Auto, and Dehumidify.
How to view and adjust the desired room temperature set point using the control buttons.
Details manual and automatic fan speed settings, control, and operation.
Covers display dimming, sleep mode, and lockout display mode for user convenience.
Step-by-step guide to enter and navigate the programming mode for system customization.
Introduces customizing functions, restoring factory defaults, and function descriptions.
Detailed explanations of individual programmable functions and their settings.
Explains shutdown due to high discharge pressure and its behavior in Cool/Heat modes.
Details shutdown due to low suction pressure, its causes, and behavior in Cool/Heat modes.
Describes shutdown due to sustained low AC line voltage and the need for calibration.
Provides a table summarizing fault codes, their descriptions, and the resulting system action.
Outlines the essential steps for the initial start-up of the air conditioning system.
Common problems and solutions for general system operation issues not related to digital controls.
Guidance on checking and cleaning condensate drains and replacing or cleaning the return-air filter.
Covers maintenance for seawater connections, pump, and strainer to ensure proper flow.
Maintenance for refrigerant status, reversing valve operation, and cleaning the condenser coil.
Describes various methods for winterizing the air conditioning system to prevent freeze damage.
Details set point range, sensor accuracy, voltage, frequency, and power consumption of the system.
Provides physical dimensions for panels and standard cable lengths for sensors and displays.
Lists the various system inputs monitored by the control, such as temperature and pressure sensors.
Illustrates the typical wiring connections for the U-Board system, including sensors and components.
Shows typical wiring connections for an older or obsolete version of the control board.
