To keep the cost of your energy bill down, you may have switched to plug-in electric panel heaters, but you’ve found your energy bills have spiked anyway, leaving you asking: why is my electric heating bill so high? Don’t worry, you’re not imagining it. Despite the marketed ‘eco-friendly’ and ‘100% efficient’ labels, a hollow system is incredibly cheap to buy and plug in, converting 100% of the electricity it draws into heat—but failing to store it.
But unfortunately, there’s a gap between what this efficiency claim actually means and what it costs homeowners in practice. With the April 2026 energy price cap sitting at 24.67p/kWh, households across the UK are realising that short-term heating solutions like plug-in electric panel heaters mean they’re coming up short.
With home insulation such a significant component to keeping your house warm, if heat escapes through drafts and poorly insulated walls as quickly as it’s generated, the heater will switch back on to replace it. This cycle can leave households caught between sitting in a cold room or suffering from an increase in their energy bills.
The ‘100% efficiency’ trap of plug-in electric panel heaters, explained
Generating heat is completely different to generating efficient heat AND keeping a room warm. It’s time to explain the ‘100% efficiency’ trap of plug-in electric panel heaters.
How an electric panel heater works
An electric panel heater works by producing heat through convection, warming the air around it. When the warm air rises, in most UK homes it reaches the ceiling, spreads out, and gradually escapes through gaps in window frames, drafty doors, uninsulated walls and into the attic.
While the heater hasn’t wasted a single watt of energy, unfortunately the heat produced has already escaped. The temperature drop triggers the thermostat, causing the heater to run again. This causes a cycle of inefficient heating, as a plug-in panel heater can be running for 45 minutes every hour just to maintain a warm temperature.
With thermal mass central to providing your home with heating efficiency, it explains why a panel heater causes your energy bills to quickly stack up.
Panel heaters vs electric radiators: how heat is stored
Compared to hollow panel heaters, Fischer’s electric radiators are built around a 40mm ceramic HeatCore — a purpose-engineered thermal mass which sits at the centre of every unit.
When Fischer’s electric radiators draw electricity, it charges the ceramic core rather than immediately releasing heat into the air. The ceramic absorbs and retains the thermal energy, releasing it slowly and steadily, even after the element has switched off. Compared to plug-in heaters, Fischer’s electric heaters don’t need to run continuously to maintain the room temperature because the 40mm HeatCore is manufactured to retain heat for longer.
The impact of radiant heat
The effect of radiant heat is often described as the difference between standing in the sun. The sun warms you through radiation, even on a cold day. In the home, radiant heat transfers energy directly to physical surfaces like the walls, furniture, floors, including keeping the people in the room nice and cosy.
With the clever HeatCore retaining the heat, as a result, this provides homes with a more consistent room temperature without the peaks and troughs that panel heaters can cause. Paired with a smart wireless thermostat, households can utilise the efficient technology to heat the spaces they’re using, and only at the time they need to be warm.
Why should landlords ditch panel heaters before 2030?
Following the updates to the Decent Homes Standard in the private rented sector, landlords need to bear in mind the new compliance to ensure they’re providing tenants with adequate heating conditions. Without this, cold surfaces are exactly where condensation and damp will form— precisely the conditions that lead to mould growth.
If a tenant is living in a property where panel heaters are the primary heat source, they have grounds to place a formal complaint under the expanded Decent Homes criteria. Therefore, landlords should consider alternative heating solutions that go beyond convection-only technology — which is all a panel heater offers.
Switching to radiant electric heating solutions means landlords can remain compliant and protect the EPC rating of their private property — a new business requirement for any private letting.
Are electric panel heaters expensive to run?
Yes — relative to the alternatives available at a similar or comparable installation cost. The purchase price of a panel heater is low, but its running cost is determined by its duty cycle (how long it needs to draw electricity per hour to maintain temperature) rather than its wattage rating alone.
Do electric heaters use a lot of electricity?
The amount of electricity used by electric heaters depends on the technology inside the heater, not the wattage on the label. For example, a hollow panel heater drawing 1.5kW and running for 45 minutes per hour uses far more electricity in a day than a ceramic core radiator of the same rated wattage. That’s because heaters built with a ceramic core only need to draw power for 20 minutes every hour as the core retains heat between cycles.
Book a free heating survey and upgrade to a truly efficient home
Convection panel heaters may seem like an easy choice in the short term, but with the heating cycle compounding your energy bills every month, they build a clear case for upgrading to radiant ceramic heating more than ever before.
Find out exactly how Fischer’s radiant HeatCore technology can future-proof your home against the changing energy price cap. Our experts provide a free, no-obligation heat-loss survey to assess your property and identify where heat is potentially being lost. From here, we will recommend the best combination of electric heating solutions specifically to your home.