Your home is fitted with a Vaillant aroTHERM Plus air source heat pump. Your heat pump is an outdoor unit that uses outside air to heat your home and hot water. It works best at consistent temperatures rather than quick bursts of heat. 

How it works

  • the outdoor unit absorbs heat from the air and transfers it inside.
  • the system runs automatically.
  • the thermostat tells the heat pump how much heat your home needs.
  • heat pumps warm homes gradually, not instantly.
  • if you increase the temperature, it can take up to 24 hours for your home to reach the new setting. 

Using your thermostat

  • your thermostat shows your current room temperature and your chosen temperature
  • adjust the temperature by pressing the button with three lines in the middle of the device and use the scroll bar
  • small temperature changes work best
  • you can set schedules for heating and hot water
  • if the room is already warmer than the desired temperature, the heating will not turn on

Useful information

  • you should leave your heating on at a range of 18-24°C (recommended setting is 21°C). The heat will be set to 21°C where it is recommended it is left. This is optimal functioning temperature for the system
  • turning the heating off completely makes it harder and slower to warm your home again
  • the system performs best when kept at a steady temperature
  • air source heating works differently to a gas combi boiler. You can’t call on immediate high levels of heat in the same way
  • in summer, you can turn the heating right down while keeping the hot water on
  • hot water is automatically set to 55°C, which the system maintains on its own
  • the water cylinder performs a night‑time disinfection cycle once a week
  • you don’t need to adjust or switch this cycle on - it’s automatic

To ensure your system runs efficiently: 

  • keep at least 1 metre of clearance in front of the outdoor unit
  • do not store items behind or around the unit
  • do not block vents or airflow
  • check the system pressure regularly. It should be between 1.0 and 2.0 bar (black numbers)
  • ideal pressure is 1.5 bar
  • if pressure keeps dropping, report it for investigation
  • if pressure is normal but a pressure/flow fault shows on your display, please report it to us via the customer portal or calling the customer contact centre

*Shared ownership customers can report faults to us within the first year. After 12 months, shared owners are responsible for any faults or repairs. Shared owners can make a claim through product guarantees/warranties or NHBC. 

Your heat pump uses a refrigerant gas. Although issues are rare: 

  • the external unit must be clear of ignition sources and needs the space to the front, rear, and sides for airflow
  • no smoking, barbecues, open flames, or petrol‑powered tools near the unit
  • press the three‑line menu button to access help topics on your thermostat
  • faults will show as messages on your control panel
  • when reporting an issue, always provide the fault message shown on screen
  • located on the outside wall
  • if it senses temperatures around 30°C or above, the heating will not turn on
  • the outdoor isolator switch is a red button on your external wall near the air source heat pump
  • this outdoor isolator switch has been fitted at a height of > 1.5m to keep out of reach of children
  • the outdoor isolator must always be ON
  • the airing‑cupboard power switch for the system must remain ON
  • the immersion heater switch must remain OFF unless Bromford advise you otherwise. Your immersion switch will be left OFF at handover
  • your power switch and immersion switch are next to each other and clearly labelled. Always ensure that you have not left the immersion switch on

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