Living with your heat pump

Living with this new, carbon-footprint-friendly hot water and heating system may take some time to learn. But once you're familiar with its steady and effective way of keeping your home warm, living with your heat pump will seem as natural as sunrise and sunset.

Scotland’s residents are set to become familiar with heat pumps this decade. Heat pumps are a vital part of the Scottish Government’s Heat in Buildings strategy, which targets switching one million homes to zero emissions heating by 2030.

If you’ve not installed a heat pump yet, don’t forget there is financial support for heat pump installation available with the Home Energy Scotland Grant and Loan. 

The quick guide to how heat pumps work

Heat pumps offer a low-carbon and more energy-efficient heating option than traditional gas and oil boilers and electric heating systems.

A heat pump warms a building by capturing heat from outside a home. The most common are air source and ground source heat pumps. The heat pump transfers heat from outside to your home. It's powered by an electric compressor, so it does use some energy, but the amount transferred is greater than the energy the compressor uses.

Therefore, heat pumps are able to deliver a greater quantity of heat into a building than the electricity used to power its systems, making heat pumps very energy efficient.

The benefits of installing a heat pump include cosy and constant temperatures and waving goodbye to hot and cold spots in your home thanks to your low-carbon emission, energy-efficient heating system.

How do you use a heat pump?

A control panel is the nerve centre of your heat pump system; your installer should have set your system to meet your heating and hot water needs. From here, you can programme settings for when you're away on holiday, ensure frost protection, fix any system errors, and programme the heat pump to turn back on for your return home.

Your installer will set what’s called a ‘weather compensation curve’ on the control panel. This curve varies the temperature of the flow temperature circulating through the radiators based on outside temperatures.

For example, if it’s freezing outside, your heat pump may circulate flows at 50°C to maintain an inside temperature of 20°C. If the day warms to 5°C, you may see the curve regulate flow temperature to 40°C to keep that stable 20°C temperature in your home.

Heat pumps also offer heating flexibility. Thermostats allow you to adjust the temperature in different rooms, and radiator valves mean you can turn off the heating in specific areas. Some heat pump models may enable thermostats to be controlled by apps on smartphones, tablets, and laptops that connect to the control panel.

The control panel allows you to adjust some or all of the following, depending on the model:

• room temperatures
• hot water temperatures
• summer, light, holiday, and other settings
• switch between heating and cooling your home
• on and off settings
• diagnose and understand potential faults
• setting up specific heating programmes.

Panels may also show the inside and outside temperatures.

What's the ideal temperature to set my home?

The ideal heat pump temperature is the lowest you feel comfortable at home. For most people, this is around 18-21°C.

Experiment by lowering thermostats one degree at a time until you find your perfect temperature. Avoid significant temperature changes—remember your heat pump takes time to bring rooms up to temperature.

Having thermostats in various rooms also gives you more control over your heating.

You can lower the temperature in rooms like bedrooms and heat others to your wishes. Do you like a warm kitchen when you wake up? Programme the kitchen’s thermostat, and you can come down to make a morning brew in a cosy atmosphere.

Should I leave my heat pump running 24/7 and overnight?

In general, it’s best to leave your heat pump on all the time—but that doesn’t mean it will be actively working and using electricity.

Heat pumps work best by keeping rooms at a consistent temperature where you feel comfortable. They only start working and drawing power once they need to heat a space.

Letting a house get cold or freezing will make the heat pump work hard and take time to bring it to your desired temperature. It may seem counter-intuitive, but heat pumps work most efficiently when left working to maintain stable temperatures.

Many people use their heat pumps to reduce their home’s temperature at night or when away during the day at work. This is called ‘set-back.’ Most people sleep better in cooler rooms and often set their temperature at around 5°C less than their daytime setting.

Don’t forget you can also control individual room temperatures with thermostats, zonal radiator controls, and closing radiator valves. Those with underfloor heating can use zone controls or thermostats to the same effect.

However, you shouldn't need to turn off your heat pump overnight. They run most efficiently when left working for extended periods. Be aware that allowing your home's temperature to drop drastically overnight means the heat pump—like all heating systems—will work harder the following morning to bring the house back to the desired temperature.

Factors affecting how you use your heat pump

You may not always be at home to monitor your heat pump, or you might want to stay cool on a hot summer's day. What if guests are staying over? Will there be enough hot water for everyone to shower?

It’s natural to wonder if your heat pump will be up to the job, come rain or shine. Below, we answer some typical questions about using heat pumps.

What is the best summer setting for heat pumps?

The weather compensation curve mentioned earlier will change the flow temps to take into account warmer outside temperatures. Alternatively, heat pumps come with ‘summer’ modes on the control panel.

People without the summer mode could also lower their thermostats, which stops the heating from turning on but means hot water will still be available.

I’m going away: what’s the ideal setting for my heat pump?

If you’re away for a day or two, it’s best to leave your heat pump settings as they are.

A more extended trip of a week or two would mean slipping the system into the 'frost protection' or 'holiday' setting on the control panel. These will prevent pipes from freezing while you're away and lower room temperatures and energy use.

What hot water temperature can an air source heat pump reach?

Your installer will set your hot water temperature based on your system and the volume of hot water your family needs. They will also establish a sterilisation cycle to ensure all stored water heats over 60°C periodically to kill harmful bacteria like legionella.

However, your hot water doesn't need to be stored at 60°C all the time as long as a regular sterilisation cycle is set. Your installer will work with you to set the lowest water temp for your needs; remember, the lower this is set, the more efficient your heat pump will be. Anything over 50°C sees most people adding cold water when bathing, something worth keeping in mind when setting the hot water temperature.

You will likely also have an electric immersion heater inside your hot water cylinder. This can provide a backup water heater. Solar water heating is another option.

Will a heat pump provide enough hot water?

A heat pump can provide plenty of hot water for bathing, washing up, and daily chores.

Your installer will have selected the correct-sized hot water cylinder for your needs based on your home’s size, the number of occupants, and general hot water use. That way, you’ll always have enough water if you’re someone who loves having guests stay or enjoy a long soak in the bath.

Do heat pumps work in very cold temperatures?

Heat pumps work well in winter and can perform in temperatures as low as -15°C or more. Locating your heat pump in a sunny and unsheltered spot helps with its running efficiency.

Many homes in Sweden, Canada, Norway and Germany have heat pumps, and these countries regularly experience temperatures lower than those in Scotland. However, if temperatures plummet below that range for a prolonged period, a rare occurrence in Scotland, then a backup is required. People who may need a backup should discuss backup boilers and heating options with installers during the planning process.