How can I help my heat pump to produce hot water as efficiently as possible?

The water temperatures generated by your heat pump will be lower than those produced by a traditional condensing boiler. It is therefore important that your controls are correctly set up to ensure that your heat pump can effectively fulfil your hot water requirements.

When considering your hot water requirements as part of your air source heat pump system, the time selection and programming set up by you and your installer will require a slightly different approach to that of a conventional gas or oil boiler. This is because an air source heat pump is not designed to supply space heating and hot water at the same time.

Using heating controls

The heating controls installed by your engineer alongside your heat pump will communicate with your heat pump to manage the space heating and domestic hot water production. Typically, these controls will involve a simple two-channel programmer that controls when your heat pump is working to provide space heating and when it is working to heat your hot water.

Some control systems will have a hot water priority control where the operation of the heat pump is automatically switched to heat hot water when required (for example when you turn on a hot water tap) and then returning automatically back to heating when the demand for hot water stops. If you are unsure about the type of controls set up with your system, please speak to your installer.

Hot water priority explained

When a domestic hot water (DHW) heating period is requested, your Grant heat pump will give priority to hot water production and temporarily deactivate the central heating. To reduce the time the central heating is inactive and to maximise central heating recovery, it is recommended that individual DHW timings are limited to short periods of no more than one hour. It is also recommended that these DHW periods should be limited to three or four times a day. Furthermore, if your installer programmes the DHW heating times to come on in the early morning and late evening, this will further enhance hot water recovery times while also ensuring the space heating temperature is maintained throughout the day. The infographic below helps explain this further.

setback controls

Please watch the video below which explains more about how your heat pump provides your hot water. You can also read our blog ‘How to Control Your Heat Pump’ to find out more about heat pump controls and settings.


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