If you’re thinking about switching your home heating to an air source heat pump (ASHP), you might be wondering: can you keep your existing traditional radiators, or will you need to replace them?
The short answer is yes, you can use an air source heat pump with traditional radiators — but there are some important things to understand before making the switch. This guide will explain how ASHPs work, how traditional radiators perform with them, and what changes you might need for a warm, comfortable, and efficient home.
What Is an Air Source Heat Pump?
Air source heat pumps work differently from traditional gas or oil boilers. Instead of burning fuel to generate heat, ASHPs absorb heat from the outside air and use electricity to compress it and warm your home. Even when it’s cold outside, ASHPs can extract heat — sometimes at temperatures as low as -15°C.
ASHPs are very efficient: for every 1 kWh of electricity they use, they can produce 3 to 4 kWh of heat. This makes them a popular choice for homeowners looking to reduce their carbon footprint and energy bills.
Traditional Radiators vs. Heat Pumps: What’s the Difference?
Traditional boilers heat water to around 70-80°C (158-176°F), which is pumped around your radiators to heat your rooms. Traditional radiators are designed to work with this high-temperature water.
In contrast, ASHPs heat water to a much lower temperature — usually between 35-55°C (95-131°F). This lower water temperature means your radiators won’t get as hot as they did before, and so they may not heat your rooms as quickly or as effectively without some adjustments.
Will My Radiators Work with an Air Source Heat Pump?
Yes, traditional radiators can work with an ASHP — but it depends on a few factors:
Radiator Size and Heat Output
Because ASHPs run at lower temperatures, your radiators need to provide the same amount of heat using cooler water. This usually means your radiators will need to be larger or you may need to add more radiators in certain rooms.
If your radiators are older, small, or inefficient, they might struggle to keep your home warm when paired with a heat pump.
Radiator Condition
If your radiators have never been serviced, have cold spots, leaks, or corrosion, they won’t perform well with an ASHP. It’s a good idea to have your radiators checked and maintained before switching heating systems.
Thermostatic Radiator Valves (TRVs)
Adding or upgrading TRVs can improve your control over room temperatures, helping your ASHP system heat your home more efficiently by avoiding overheating or wasted energy.
What If My Radiators Aren’t Big Enough?
If you find your current radiators aren’t heating rooms adequately at lower temperatures, here are some options:
- Upgrade your radiators: Bigger, modern radiators with larger surface areas can provide more heat with cooler water.
- Add more radiators: Installing extra radiators in poorly heated rooms helps balance heat output.
- Supplement with underfloor heating: Combining underfloor heating downstairs with radiators upstairs can give you the best of both worlds.
Benefits of Keeping Traditional Radiators with an ASHP
- Less disruption: Retaining your existing radiators means less invasive work and potentially lower installation costs.
- Familiar heating feel: Many homeowners prefer the look and warmth of traditional radiators.
- Flexibility: You can gradually upgrade radiators over time instead of replacing everything at once.
Things to Consider Before Switching
- Your home’s insulation: Well-insulated homes work best with ASHPs and lower water temperatures. If your home is poorly insulated, your radiators may struggle even if they are the right size.
- Boiler backup: In very cold weather, some ASHP systems have a backup electric heater or boiler to provide extra warmth.
- Professional assessment: Always get a heating engineer to survey your home and heating system before installing an ASHP.
What Does Installation Involve?
Installing an air source heat pump means removing your existing boiler and fitting the ASHP outside your home. Inside, your existing pipework and radiators will be connected to the new system — but it’s important that your radiators are suitable and possibly upgraded to work efficiently.
The engineer will assess your home’s heating needs, radiator sizes, and insulation levels to design the best solution.
Is It Worth Keeping Traditional Radiators?
Many UK homeowners successfully use ASHPs with traditional radiators. If your radiators are in good shape and your home is well insulated, you might only need minor adjustments.
However, if your radiators are small or your home is drafty, you might find better comfort and efficiency upgrading to larger radiators or adding underfloor heating.
Ready to Make the Switch?
An air source heat pump is a smart choice to lower your energy bills and carbon footprint — and yes, you can often keep your traditional radiators with a few tweaks.
If you want expert advice on whether your radiators will work with an ASHP or if you need upgrades, contact the team at NCS today. We’ll help you find the best, most efficient heating solution for your home.
