Heating systems

cold wintery fields

On this page you'll find useful information to help you use your air source heat pump, storage heaters or combi boilers most efficiently.​

Air source heat pumps

When used correctly, air source heat pumps should save you money.
It can take a while to get used to them, as they work quite differently to other types of heating systems.

It's better financially, and for the system to work most efficiently, for the unit to be left at a desired temperature all the time. Turning on and off costs more money and, in the cold weather, the units can take hours to catch up to your desired temperature. We recommend leaving it at a minimum temp of 18 degrees at all times.

Tips on using your heat pump system efficiently

  • Low and slow heating

    How do air source heat pumps work?

    Air source heat pumps take warmth from the air outside (even when it’s freezing) and use it to heat your home.

    They can take a while to get used to, as they operate differently to other types of heating.

    Low and slow

    Air source heat pumps are designed to heat to low temperatures over a long period of time, rather than quickly providing heat when turned on.

    One cycle at a time

    ASHPs work very differently to a gas boiler – as they have to complete one cycle before moving onto the other. Therefore if it is getting the hot water up to temperature it will not do heating and vice versa.

  • Changing the temperature in your home

    We advise you to leave the heating ON at a desired temperature.

    Heat pumps are designed to run for long periods of time. This means it is usually cheaper and warmer to leave them running continually, compared to only heating in the morning and evenings as you may have done with your previous heating system.

    We recommend leaving it at a minimum temperature of 18 degrees at all times.

    They respond slowly to temperature changes

    If you want to turn the temperature up, we suggest changing the setting of your room thermostat by one or two degrees at a time. Wait to see if you are comfortable at this new temperature before turning it up further.

    If you turn the temperature up too quickly, the heat pump can't respond quickly enough and will run at an increased capacity to boost the temperature, using more energy and costing more.

    You may need to wait for it to heat up to a higher temperature

    If you have it on a constant desired temperature and turn it up slowly you won't need to wait long.

    However, if you've had it turned down low, or off, then it may take up to a whole day to get back to the desired temperature. And every time it's turned off or down again the cycle starts again.

    Increasing the temperature will NOT make it heat up quicker.

  • Will turning it down or off save energy costs?

    No. We advise you to leave the heating ON at a desired temperature.

    Don't turn it up and down.

    ASHPs don't work like gas central heating.  Although it may seem more economical to turn it off or down to a really low temperature when you go to bed or out of the house, the system has to work harder to get back up to a desired temperature, using more energy and costing more.

  • Defrosting or a water leak?

    It may look like a leak, but it's probably defrosting

    Water from the small pipe on the outside unit is normal, and if it looks like a significant leak coming from the outdoor unit, the unit will most likely be doing a defrost, which happens more often in the winter temperatures.

    This is a normal process but will turn off the heating and hot water for approx. 10 mins whilst the cycle is running.

    Unless you've lost pressure in the heating system, this water is not a leak.

    If you have lost pressure

    If you have lost pressure, please contact the Customer Care Team to request an engineer to visit on 0300 1234 009 or enquiries@midlandsrural.org.uk

  • Frozen pipes

    The condensating pipe can freeze, but the condensate doesn't stop the unit working.

    In freezing temperature your pipes may freeze. Unfortunately with below zero temperatures, we will not be able to do anything until the temperature rises. If you have lost pressure and your heating has stopped working, please get in touch on 0300 1234 009.

  • Radiators will feel warm, not hot

    ASHPs are a low-temperature heating system, so your radiators will feel warm, but not hot, to the touch.

    If your radiators are hot at the top and cold at the bottom, this is how a normal radiator works regardless of gas/ASHP, eventually the hot water falls to the bottom creating an overall warmth from the radiator.

  • Think the heating isn't working correctly?

    If you don’t feel comfortable in your house in winter, it’s probably not an issue with the heat pump.

    If there is something critically wrong with the heat pump, the control screen will tell you. Anything else is likely to be a setting or control issue.

    If you're not comfortable and would like help with your system, please get in touch with us on 0300 1234 009 or email enquiries@midlandsrural.org.uk

  • Make sure you're on the best tariff for an ashp

    Being on the right tariff is really important, as it will save you money

    It’s really important to check that you are the best tariff for an ashp. If you're on a tariff with on- and off-peak rates, such as economy 7, 10 or 14, you will be paying unnecessary higher rates. Please advise your energy provider that you need to change to the best single tariff for your home.

Storage heaters

Storage heaters are designed to work with a two rate energy tariff, to make use of cheaper, overnight electricity. See below for advice on using your heaters efficiently.

Tips on using your storage heaters efficiently

  • How do storage heaters work? 

    Storage heaters are designed to work with a two rate energy tariff, to make use of cheaper, overnight electricity.

    Overnight they absorb and store up energy, which is then released to heat your home the following day.

    It's important to get the settings right, otherwise you could be wasting power and money.

    Each heater in your home works independently, so you'll need to set each of them.

    And, if you find you're running out of heat during the day, you may need to store a bit more. Take a look at how to control your heater and how to use it most cost efficiently below.

  • How do you control storage heaters?

    Each heater has two controls: input and output.

    Controlling the balance between the input and output will determine how much energy they use and how effective they are at heating your home.


    • This controls how much energy you want to store up overnight.
    • The numbers on the input control typically run from 1 (low) to 6 (high). The higher the number, the more energy your heater will store overnight, and the more electricity it will use.
    • You’ll need to store up more energy during the winter nights, to make sure you’ve got enough heat to last throughout the next day. So, when it starts to get cold, keep the input dial at somewhere between 4 and 6.
    • In spring and autumn, keep the input dial somewhere between 1 and 3. You won’t need the heating on as much during the day by then, so you don’t need to store up as much energy overnight.


    • This controls how much heat you want to give out throughout the day, which will affect how quickly the stored heat is used.
    • During the day, turn the output control up or down to heat your home as and when you need to.
    • The higher you turn it up, the warmer it’ll feel. But by doing that, you’ll also be using up more of your stored energy.
    • By gradually releasing heat throughout the day at a low setting of about 1 or 2, you should have enough to turn it up in the evening, when it’s usually a bit colder.


    Some storage heaters also come with a ‘boost’ setting, to give you an extra blast of heat if you need it. However, this may use more expensive peak-time electricity, rather than the energy stored in your heater from overnight.

    You should adjust the controls throughout the year, to avoid using more energy than you need. Find out more about how to use your heater most cost efficiently below.

  • How do you use storage heaters most efficently?

    Firstly, make sure you're on an Economy 7 or Economy 10 energy tariff.

    This is essential, as it makes it affordable to charge your heaters when the energy is at it's cheapest overnight.

    If you use your heaters effectively, by adjusting the input and output, you could save money.

    Input adjustment advice:

    • Forward plan: check the weather forecast for the next day, so you know how much to charge your heaters.
    • Set the input based on energy needs for next day - the higher the number, the more energy is stored and the more electricity used.
    • Only charge heaters in the rooms you'll use the next day.

    Output adjustment advice:

    • Set the output to the lowest setting at night, normally 0 or 1, to avoid wasting heat
    • If you’ll be out during the day, remember to turn the output control right down before you leave, to avoid using up energy.
    • During the day, gradually turn the output from low to high to high starting at one and move up one dial at a time if you feel cold. This way you can retain heat for the evening.
    • Don't block the heaters with furniture / curtains

    Switch it off:

    • In the summer, or when you don't need any heating, switch the heater off at the wall.

    And, don't forget...turn the output control down before you go to bed and when you go out to save heat and money.

  • Help with your heater

    If you need any help understanding how to use your storage heater please get in touch by email or call on 0300 1234 009.

Combi boilers

A recent study by Nesta found that households can save gas by reducing the heating flow temperature on their condensing combi boiler.

Reducing heating flow temperature

  • Make best use of your boiler

    Turn your heating on when you need it

    • It’s better to turn your gas boiler off and on when you need it, or just use it to heat the rooms you’re in rather than having it on low all the time.
    • If you leave the house for a few hours, turn your heating off. It’s cheaper to reheat your home than it is to keep it on low all day when you’re not there.

    Get to know your heating controls

    Your room thermostat should be set to the lowest comfortable temperature, which for most people is between 18 degrees and 21 degrees. Turning your thermostat down by just one degree could typically save you £145 a year on energy bills.

    If you need help with your heating controls, please get in touch with us on 0300 1234 009 or at enquiries@midlandsrural.org.uk

  • Lowering combi boiler temperature flow

    Your heating flow temperature handles the temperature that your boiler heats water up to, before sending it off to your radiators.

    When your boiler is installed the flow temperature is usually set to around 70°C-80°C. This is too high. Combi boilers work most
    efficiently when this water is heated to 60°C or below.

    Why is it more efficient to reduce flow temperature?

    At lower flow temperatures the combi boiler is in condensing mode more often. This means the combi boiler can capture more heat and recycle it back into the system. Lower flow temperatures result in a more efficient combi boiler, that uses less gas to heat your home up to the same temperature.

    Your boiler flow controls are separate from your central heating controls

    Your boiler controls are separate from your central heating controls, such as your room thermostat, programmer and radiator valves. The central heating controls turn your heating on and off, while the boiler thermostat changes the temperature of the water in the system.

    It’s important to get your heating controls right first before you try to adjust the boiler’s flow temperature with your boiler’s thermostat.

    Will it make my hot water colder?

    No, reducing the flow temperature on a combi boiler won’t affect the temperature of the hot water from your taps and showers, but it can save you money.

    What about regular boilers?

    Regular boilers with a separate hot water cylinder must not be set lower than 65 degrees to prevent harmful bacteria.

    For further info:

  • How much can I save by reducing the heating flow temperature on my combi boiler?

    New research from the Salford Energy House found that lowering your heating flow temperature on a combi boiler resulted in gas usage savings of:

    • up to 9% by lowering the temperature from 80°C to 60°C
    • up to 12% by lowering the temperature from 80°C to 55°C

    People who may be more vulnerable to the cold should be careful when reducing the flow temperature. For example, if you're elderly or have underlying health conditions, innovation charity Nesta recommends not turning it below 60°C.

  • Plug-in heaters or central heating?

    Bedrooms are typically cooler rooms in the home, so using an electric blanket or hot water bottle can be a cost effective way to get some added warmth for a short period of time.

    Gas is still a cheaper fuel than standard rate electricity, so if you have gas central heating, it’s generally advisable to use this over individual electric heaters. The exception may be if you only want to heat one room for a short period of time.

    Some plug-in heaters are available with a thermostat, and some have a timer – you can use these to avoid using more electricity than you need. Make sure you always turn them off when leaving the room. If you’re heating more than one room with electric heaters, you’ll probably be better off using the central heating.

    Info from Energy Saving Trust