Why is my house cold with a heat pump?

Key takeaways

• Warm radiators don’t need to be hot. Heat pumps heat your home differently to a gas boiler, using lower-temperature water over longer periods.
• A heat pump should maintain a steady temperature. Turning it on and off like a boiler can make your home feel colder and reduce efficiency.
• If your home never reaches the temperature you’ve set, it’s worth checking your settings, insulation or speaking to your installer.

If you’ve recently switched to a heat pump, or you’re researching one before making the change, you may have heard that homes feel colder with a heat pump.

Fortunately, that’s one of the biggest myths about heat pumps.

Unlike a gas boiler, which quickly heats your radiators before switching off again, a heat pump works differently. It supplies your heating system with lower-temperature water for longer, gently replacing the heat your home naturally loses throughout the day.

The result is a more consistent, comfortable temperature – without the intense bursts of heat you’re used to from a boiler. By heating your home steadily instead of in short bursts, heat pumps use less energy and are much more efficient.

If you do have a heat pump already, and your home genuinely isn’t reaching the temperature you’ve set, though, there are a few things worth checking.

Is your home actually cold?

One of the biggest surprises for new heat pump owners is that the radiators don’t feel as hot as they did with a gas boiler.

That’s completely normal.

A gas boiler might heat your radiators to 70–80°C. A heat pump typically runs at a much lower flow temperature of around 35–45°C. That means your radiators feel warm rather than piping hot.

But remember, your heat pump isn’t trying to heat your radiators. It’s trying to heat your home.

If your thermostat says 20°C and your home feels comfortable, your heat pump is working exactly as it should.

Are you using your heat pump like a gas boiler?

Heat pumps are designed to maintain a steady temperature, not heat your home as quickly as possible.

So, if you’re turning your heating off overnight, only switching it on for a few hours each day, or turning the thermostat right up when you feel cold, your heat pump will have to work much harder to catch up.

Instead, leave your heat pump running and let it maintain a comfortable temperature throughout the day. If you’d prefer a cooler bedroom overnight, simply reduce your thermostat by 1–2°C or turn down your radiator valves rather than switching the system off completely.

Ultimately, your heat pump works best when you set it and forget it. 

Is your home losing heat?

It doesn’t matter which heating system you have; it has to replace the heat your home loses.

If your home isn’t well insulated, heat can escape through your roof, walls, windows and doors faster than the heat pump can replace it. That doesn’t necessarily mean there’s a problem with the heat pump – it simply means it has to work harder.

Simple improvements like topping up your loft insulation, reducing draughts and upgrading older windows can all help your home stay warmer for longer.

Learn what actually drives heat pump efficiency in a UK home.

Are your radiators the right size?

Heat pumps work most efficiently at lower flow temperatures than a boiler system.

Because the water circulating around your heating system isn’t as hot as it would be with a boiler, your radiators need enough surface area to comfortably heat each room.

That’s why some homes need larger radiators when switching to a heat pump. It’s not because the heat pump isn’t powerful enough – it’s because larger radiators can release the same amount of heat using cooler water.

At Aira, we assess every room during your Home Energy Assessment to make sure your heating system is designed to keep your home cosy.

Have you checked the basics?

Before assuming something’s wrong, it’s worth checking a few simple things:

• Is your thermostat set to the temperature you’d like your home to be?
• Is your heating programmed to come on when you expect?
• Is the outdoor unit free from leaves, snow or anything blocking the airflow?
• Are all your radiators turned on and able to circulate heat properly?

Sometimes, a small adjustment is all it takes.

Could it be the defrost cycle?

On particularly cold mornings, you may notice your heat pump briefly stops heating or starts making a different sound.

This is called the defrost cycle, and it’s completely normal.

As your heat pump extracts warmth from the outside air, frost can build up on the outdoor unit. Every so often, the system automatically removes this frost to keep everything running efficiently.

The process usually lasts just a few minutes before normal heating resumes.

How does Aira Intelligence help?

With the Aira Heat Pump, Aira Intelligence continuously works in the background to keep your home cosy.

It monitors outdoor temperatures, weather forecasts and how your home warms up, then automatically fine-tunes your heating throughout the day. That means your heat pump is always working to maintain your chosen temperature while using as little energy as possible.

Instead of constantly adjusting your heating yourself, Aira Intelligence does the hard work for you.

When should I contact my installer?

It’s worth getting in touch if:

• Your home never reaches the temperature you’ve set.
• Your heat pump suddenly starts behaving differently.
• The outdoor unit stays covered in ice for a long time after the defrost cycle should have finished.
• You notice unusual noises or error messages.
• Your energy bills have increased significantly without an obvious reason.

These could indicate that your settings need adjusting or that your system would benefit from a professional check.

The bottom line

If your home feels different after switching to a heat pump, that’s perfectly normal.

Heat pumps don’t produce short bursts of intense heat like a gas boiler. Instead, they gently maintain a comfortable temperature using lower-temperature water over longer periods.

If your home is reaching the temperature you’ve set, your heat pump is doing exactly what it was designed to do. And if it isn’t, checking your settings, insulation and heating system is usually the best place to start. If the issue persists, contact your installer for help.