What does yellow alert flash code 3 mean on my Bosch TW Heat Pump?
A yellow alert flash code 3 on your Bosch Heat Pump indicates short cycling. This can be due to an intermittent thermostat demand signal, a defective time delay relay or control board. If a high-pressure switch is present, refer to Flash Code 2 information; if a low-pressure switch is present, refer to Flash Code 1 information.
What does yellow alert flash code 4 mean on my Bosch TW?
A yellow alert flash code 4 on your Bosch Heat Pump indicates a locked rotor. This could be due to a failed run capacitor (verify if it's bad), low line voltage (contact utility if voltage at disconnect is low and check wiring connections), excessive liquid refrigerant in the compressor, or seized compressor bearings (measure compressor oil level).
What does yellow alert flash code 5 mean on my Bosch Heat Pump?
A yellow alert flash code 5 on your Bosch Heat Pump indicates an open circuit. Possible causes include: 1. An open outdoor unit power disconnect. 2. An open compressor circuit breaker or fuse(s). 3. A failed open compressor contactor. Check the contactor wiring and connectors, look for signs of failure (burned, pitted, or open), and check for low pilot voltage at the compressor contactor coil. 4. An open high-pressure switch that requires manual reset. 5. An open circuit in the compressor supply wiring or connections. 6. An unusually long compressor protector reset time due to extreme ambient temperature. 7. Damaged compressor windings. Check the compressor motor winding resistance.
Why does my Bosch TW Heat Pump short cycle?
Your Bosch Heat Pump might be short cycling due to several reasons. The unit may be oversized, requiring a recalculation of heating and cooling loads. The thermostat might be installed near a supply air grill, in which case you should relocate it, or the heat anticipator may need readjustment. Also, check for a defective or improperly calibrated low-pressure switch.
What to do if there is no or low flow in my Bosch TW?
If you're experiencing no or low flow in your Bosch Heat Pump, consider the following: * Check the power supply. * Ensure the on/off switch is in the “ON” position. * Engage the heat pump contactor. * Repair or tighten any broken or loose wires. * Purge air from the piping system. * Remove the pump cartridge and clean if the pump shaft/impeller is stuck. * Replace the pump if it is defective. * Repair any kinks in the water piping and check for proper line size.
What to do if my Bosch Heat Pump unit is off on low pressure control?
If your Bosch Heat Pump unit is off due to low pressure control, it could be due to several reasons. If in cooling mode, there may be a lack of or inadequate source-side fluid flow, or the entering water temperature may be too cold. If in heating mode, there may be a lack of or inadequate water flow, the entering water temperature may be too cold, or the condenser may be scaled or plugged. Also, the unit might be low on refrigerant. In this case, check for a refrigerant leak, repair it, evacuate, and recharge with the factory-recommended charge. Finally, there may be a defective or improperly calibrated low-pressure switch.
What to do if my Bosch TW Heat Pump unit is off on high pressure control?
If your Bosch Heat Pump unit is off due to high pressure control, it could be due to several reasons. If in cooling mode, there may be a lack of or inadequate water flow, the entering water temperature may be too warm, or the condenser may be scaled or plugged. If in heating mode, there may be a lack of or inadequate load-side fluid flow. Also, the unit might be overcharged with refrigerant. In this case, reclaim the refrigerant, evacuate, and recharge with the factory-recommended charge. Finally, there may be a defective or improperly calibrated high-pressure switch.
Instructions for mounting the unit on a vibration absorbing pad.
Lists default UPM board parameter configurations.
Details UPM board DIP switch default positions for functions.
Describes UPM features like anti-short cycle, random start, low pressure bypass.
Lists key features of the Bosch water heat pump controller.
Details unit operational modes: Off, Heating, Cooling.
Describes controller protection against faults and ensuring safe operation.
To Next Page
General