Octopus Energy Cosy 6 Heat Pump Problems & Solutions

Complete diagnostic guide for Octopus Energy Cosy 6 heat pumps in the United Kingdom.

Note

The Octopus Energy Cosy 6 heat pump uses an intelligent control system. Specific numeric error codes may not be visible on the display. Instead, problems are often indicated by symptoms and behavior of the heat pump. The following information is based on common problems and their solutions.

Temperature and Heating Problems

Common problems with temperature control and heating function in Octopus Energy Cosy 6 heat pumps.

Problem	Description	Possible Causes	Solutions
Cold Radiators	Radiators remain cold or do not get warm enough	Target temperature already reached Weather compensation active Temperature sensor incorrectly positioned Heating circuit not fully bled Low water pressure in system	Check if target temperature is reached - this is normal with weather compensation active Check temperature sensor position - should not be near heat sources or draughts Bleed heating circuit completely Check water pressure in system (should be between 1.0-1.5 bar) Check thermostat settings Contact Octopus Energy Support if problem persists
Heat pump switches off before reaching desired temperature	The heat pump stops heating before the desired temperature is reached	Temperature sensor incorrectly positioned Temperature sensor near heat sources Temperature sensor in draught Problems with temperature control Weather compensation active	Check temperature sensor position Ensure sensor is not placed near heat sources (e.g. lights, appliances) Ensure sensor is not in draught Check temperature control Check weather compensation settings Reposition sensor if necessary
House is too warm	The heat pump heats the house beyond the desired temperature	Thermostat settings too high Boost function activated Weather compensation settings incorrect Temperature sensor defective or incorrectly positioned	Check thermostat settings and reduce if necessary Check if boost function is activated and deactivate it Check weather compensation settings Check temperature sensor function Adjust settings if necessary

Visible Signs and Appearances

Normal appearances and signs that may occur with Octopus Energy Cosy 6 heat pumps.

Problem	Description	Possible Causes	Solutions
Steam or smoke from heat pump	Steam or smoke is visible during operation	Normal defrost cycle Condensation during operation Weather conditions (cold weather)	Steam during defrost cycle is normal and not a cause for concern Condensation may occur in cold weather - this is normal If steam occurs continuously and is not related to defrost cycle, contact Octopus Energy Support
Ice formation on the back of the heat pump	Ice forms on the outdoor unit of the heat pump	Normal defrost cycle Cold weather conditions Humidity in the air	Ice formation in cold weather is normal and part of the defrost cycle The heat pump should automatically defrost If ice does not defrost or forms continuously, contact Octopus Energy Support Do not attempt to remove ice manually

System and Performance Problems

Problems with system performance and general functions of the Octopus Energy Cosy 6 heat pump.

Problem	Description	Possible Causes	Solutions
Heat pump does not start	The heat pump does not respond or does not start	Power failure or power interruption Fuse tripped Main switch turned off Electronic error Problems with power supply	Check if power is available Check fuses Check main switch Restart system Contact Octopus Energy Support if problem persists
Unusual noises	The heat pump makes unusual or loud noises	Normal operation (fan, compressor) Contaminated or blocked components Loose parts Wear parts	Some noises are normal during normal operation Check if components are blocked or contaminated Contact Octopus Energy Support for very loud or unusual noises Do not attempt to repair the heat pump yourself
Low water pressure	Water pressure in heating system is too low	Water loss due to leakage Bleeding problems Defective expansion vessel Normal evaporation over time	Check water pressure (should be between 1.0-1.5 bar) Check system for leaks Bleed heating circuit completely Refill water if necessary Check expansion vessel Contact Octopus Energy Support if problem persists

Need More Help?

If you are experiencing problems with your Octopus Energy Cosy 6 heat pump that are not covered by this information, or if the provided solutions do not resolve your issue, we recommend:

Consult the official Octopus Energy support page for heat pumps
Contact Octopus Energy customer service in the United Kingdom:
- Phone: 0808 196 6842
- Email: heat@octopus.energy
- Support page: octopus.energy/heat-pump-help/cosy/
Seek help from a qualified heat pump repair technician
Check warranty coverage if your heat pump is still under warranty

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