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Heat pumps are fast becoming the beating heart of the UK’s transition to low-carbon homes. Efficient, electric, and renewable-ready, they offer a smart alternative to gas and oil heating, reducing both carbon emissions and long-term energy costs.
But there’s a quiet risk that many homeowners don’t see coming.
A heat pump is only as good as the system that supports it. If poorly designed or badly commissioned, what should be an efficient, future-proof heating solution can become an underperforming liability, costing you comfort, money, and peace of mind.
A heat pump isn’t a like-for-like replacement for a boiler. It works differently. While boilers produce short, high bursts of heat, heat pumps operate at lower temperatures over longer periods. This means everything from pipework to radiators to controls must be carefully calibrated for your home.
System design is the foundation. It determines the correct heat pump size (bigger isn’t always better), the type of emitters you’ll need (radiators, underfloor, or a mix), flow temperatures, and heat loss calculations. Commissioning, meanwhile, ensures the system is installed and configured to run exactly as intended. You want the right amount of heat, in the right place at the right speed for maximum efficiency and savings.
When either step is skipped or rushed, performance drops, and problems begin.
If your heat pump is undersized or radiators aren’t matched to lower flow temperatures, your home may never reach the desired temperature, especially in colder months. This leads to constant tinkering with settings, discomfort, and disappointment.
2. Excessive electricity use
An incorrectly designed system often runs harder and longer than necessary. The compressor may short-cycle (frequent starts and stops), reducing lifespan and increasing wear. The result? Higher electricity bills and a frustratingly inefficient system.
3. Reduced efficiency and COP
The Coefficient of Performance (COP) is the key efficiency metric for heat pumps. A well-designed system can achieve a COP of 3–4 (i.e. 3–4 units of heat for every unit of electricity). Poor design can cut this significantly, undermining the financial and environmental case.
4. Noise complaints and mechanical stress
Overworked or incorrectly installed systems may generate unwanted noise from the outdoor unit or internal components. This is not just annoying; it can be a symptom of deeper mechanical stress and eventual breakdown.
5. Poor integration with solar and battery systems
If you’re planning a fully electric home with solar PV and battery storage, the integration must be carefully designed. An inefficient heat pump can negate the benefits of your solar generation or drain battery reserves faster than necessary.
6. Voided manufacturer warranty
Many manufacturers require evidence of proper commissioning, including key performance data and flow temperature settings. If these aren't properly recorded, you may struggle to claim on a warranty if something goes wrong.
Even if you've already had a heat pump installed, these red flags could indicate underlying design or commissioning issues:
Insist on a full heat loss calculation and understand the assumptions
This is non-negotiable. It should be done room-by-room and include building fabric, window performance, and ventilation losses. It’s also important to understand and be clear about what assumptions have been made in order to create your quote and propose a design.
Work with certified professionals
Choose an installer certified by recognised schemes like MCS (Microgeneration Certification Scheme) professionals who can demonstrate the technical knowledge, experience, and compliance required to install renewable systems safely and effectively.
We’re also proud members of SNIPEF (Scottish and Northern Ireland Plumbing Employers’ Federation), a membership that goes beyond the basics. SNIPEF sets additional standards for professionalism, training, and accountability, ensuring its members uphold best practices and deliver consistently high-quality work.
When you choose a certified and accredited installer, you're not just getting a heat pump, you're getting peace of mind.
Request a commissioning report
You should receive clear documentation of system setup, flow rates, temperatures, and performance expectations.
Think holistically
Don’t treat the heat pump in isolation. Consider your home’s insulation, hot water needs, and whether smart controls or zoning would enhance performance.
A well-designed, expertly commissioned heat pump can deliver exceptional performance, comfort, and savings for years to come. But cut corners, and what should be a smart, sustainable investment can quickly become a source of stress, spiralling costs, and long-term inefficiency.
A Heat Pump should be a long-term asset, not a costly mistake
When done properly, a heat pump system is more than a heating upgrade; it’s an infrastructure transformation. With the right system design, including accurate heat loss calculations, appropriately sized emitters, and properly configured controls, your home is set up not just for today, but for decades to come.
And here’s the real long-term benefit: when the time comes to replace your heat pump, typically 15–20 years down the line, a correctly designed system means you’ll only need to swap out the heat pump unit itself. Your pipework, radiators, controls, and system architecture will still be fit for purpose, future-ready, and fully optimised.
It’s a one-time design decision that protects your comfort, efficiency, and investment for the long haul.
If you’re considering a heat pump or want a second opinion on an existing system, our team can help. We design, install, and commission systems that are truly built to perform: intelligently engineered, carefully configured, and ready for the low-carbon future.
To discuss your home heating system and heat pump project get in touch with our team today.
