Spend any time on social media and you’ll see people claiming that “heat pumps just don’t work in UK houses”, or that “you’ll need to rip out all our pipes and radiators” and other such claims that make the prospect of swapping out your gas boiler for a new heat pump somewhere between eye-wateringly expensive and simply impossible.
But now that tens of thousands are being fitted per year it has become clear that the heat pumps can be installed to our homes and function perfectly well.
However, lingering doubts may well persist and even with grant funded installs a heat pump is still likely to cost several thousand pounds more than a gas boiler, so people want to get it right.
If you are in the position that you want to benefit from getting gas out of your home, but are nervous about encountering problems and regret with a heat pump install then read on because you can quite easily simulate a heat pump installation using your existing gas boiler, and you’ll soon have a good idea if you can ‘drop’ in a heat pump in without fuss.
In the most basic terms heat pumps run cooler and longer, so reducing the temperature of the radiators but leaving them on for longer is the aim.
Running Your Gas Boiler at 55°C: Simulating Heat Pump Efficiency in Your Home
You can simulate the efficiency of a heat pump by lowering their boiler's flow temperature to around 55°C. This will help you understand how a heat pump is suited to your home and can also save energy, reducing your bills and carbon footprint. Here's how you can do it.
The flow temperature is the temperature of the water that your boiler sends to your radiators or underfloor heating system. Traditional gas boilers are often set to high flow temperatures (typically 60-80°C) to quickly heat a home. However, this high-temperature operation is relatively inefficient and wastes energy with properties internal temps swinging up and down.
Heat pumps, on the other hand, operate at lower flow temperatures (typically 35-55°C). By lowering your gas boiler's flow temperature to 55°C, you can mimic the way a heat pump heats your home helping you understand how your home performs with constant lower-temperature heating.
(We suggest 55°C rather than any lower as even though heat pumps generally run cooler than that, they also run at higher water flow rates which compensates for that difference.)
1, Check Your Boiler's Manual: Not all boilers allow you to adjust the flow temperature, so consult your manual or contact the manufacturer to ensure your boiler can operate at 55°C. Most modern boilers have a dial or digital interface to adjust the flow temperature. Set it to 55°C for central heating. If you have a combi boiler, you may need to set a separate temperature for hot water (typically around 50-55°C to ensure safety and comfort).
2, Ensure your radiators valves are fully open to let the lower temperature water flow without restriction.
3, Set your timer for a much longer run than usual, maybe even a steady 18 hours of heating. If you have a smart meter installed then you’ll be able to monitor the cost as you go along.
Slower Heating: Your home will take longer to heat up compared to high-temperature systems. This is normal and mimics the operation of a heat pump.
Consistent Comfort: Once your home reaches the desired temperature, it will stay warm for longer due to the steady, low-temperature heating.
Older and smaller radiators may struggle to emit enough heat at 55°C. If certain rooms feel too cold, then it suggests that larger radiators will be needed in those locations.
Click to check out this money saving boiler challenge from NESTA.
Running your gas boiler at a flow temperature of 55°C is a practical way to simulate the efficiency and operation of a heat pump. While it may require some adjustments to your heating system and habits, the benefits—reduced energy bills, lower emissions, and improved comfort—are well worth the effort.
Regardless of this ‘test’ you may well find that you prefer the lower flow temperatures that encourage longer heating cycles. They can create a more consistent and comfortable indoor environment compared to the short, intense bursts of heat from high-temperature systems.
