Don’t Install a Heat Pump Until You Read This

Mars · 2024-12-15T22:36:31Z

If you’re considering a heat pump or had one recently installed, this article is for you. Our six-year journey with a heat pump has been a rollercoaster of expensive mistakes, lessons learned and a mission to help others avoid our pitfalls. Heat pumps are incredible technology when installed and designed correctly. But when things go wrong, they can become a source of great frustration. Here’s what you need to know to ensure your heat pump journey is a success. The Start of Our Heat Pump Journey Six years ago, after an extensive vetting process, we appointed Global Energy Systems to install our air source heat pump. Global Energy Systems supplied the unit and subcontracted the physical installation to another MCS-accredited company, All Seasons Energy, while maintaining the full contract with us. From the very beginning, it was evident something was amiss. The first three winters were plagued with issues: rooms that wouldn’t heat properly, issues with the controls and higher than expected running costs, temporarily obscured by the cushion of cheap electricity tariffs at the time. Each time Global Energy Systems dispatched a team to address our concerns, we talked ourselves into believing things had improved – perhaps out of desperation to justify the £16,000 investment in the system. But as soon as the next cold spell hit, the same problems reared their ugly heads. In hindsight, it’s glaringly obvious: the installation wasn’t just flawed – it was fundamentally botched from the start. A System That Was Never Designed to Work One of the biggest revelations came years later as we gradually started to educate ourselves on low temperature heating: our system as a whole was never designed to work properly with a heat pump. Instead, it was slapped in to run like a boiler. This critical error was evident from the start, but we didn’t know enough then to question it. The heating services and operations engineer from Global Energy Systems commissioned our system to run on a 45°C set point – a decision that is utterly indefensible if you understand how heat pumps should work. Heat pumps are designed to operate most efficiently at lower flow temperatures: the higher the flow temperature, the more energy they consume, driving up costs and eroding efficiency. Shockingly, when we inquired about weather compensation – a feature that optimises system performance by adjusting flow temperatures based on outdoor conditions – Global Energy Systems outright denied that their heat pump had this capability. This was a blatant lie. Years later, after tinkering with the control panel, we discovered weather compensation settings and heat curve adjustments buried in the system. Global Energy Systems, it seems, had deliberately chosen to run the system at a fixed 45°C, not for our benefit, but to mask deeper issues with the system’s design and performance. As we learned more about heat pumps, we suspected that a proper heat loss calculation and heating design had never been done. When we confronted Global Energy Systems, they admitted it hadn’t. This was a massive blunder. Proper heat loss calculations are the cornerstone of any heat pump installation. Without them, you’re essentially flying blind, which explains the inadequacies of our system. The Saga of Cold Rooms and Circulation Pumps For years, cold spells exposed more limitations of our system. The north end of our house – where the index circuit is – struggled to exceeded 16°C when outdoor temperatures dropped below 3°C. Global Energy Systems' solution? Add more or upsize circulation pumps. We now have four, and they haven’t resolved the problem. Instead, they’ve increased our running costs. When we had our system evaluated by some of the UK’s top installers, their feedback was unanimous: the system had no design and was set up to fail. As Ken Bone explains in the video below, it was essentially running as a boiler replacement with a Delta-T of 20, littered with on/off stats, which is unsuitable for a heat pump. Our house as a whole never had a chance of being heated efficiently.Lessons Learned Insist on a Proper System Design Before installation, double, triple and quadruple-check that your system is designed properly. Ensure every room and heat emitter can hit its target temperature (19°C, 20°C or 21°C, depending on your preference). Get this in writing. These temperatures must be achievable when running weather compensation. Don’t let your installer convince you to settle for a fixed flow temperature. In mild months, this approach wastes energy and money. Understand the Importance of Controllers Heat pumps are fundamentally all very similar at their core: a metal box with pipes, refrigerant and a compressor. The controller, however, is what determines how effectively the system runs and does what you want it to do. In our case, the controller from Global Energy Systems has been dreadful. As we have a hybrid system, it can’t even run weather compensation if we wanted to use th...

Page 2 / 2 Prev

Air Source Heat Pumps (ASHPs)

Last Post by davidnolan22 6 minutes ago

13 Posts

5 Users

4 Reactions

879 Views

RSS

davidnolan22

(@davidnolan22)

Reputable Member Member

Joined: 10 months ago

Posts: 125

21/11/2025 6:16 am

@editor the size matches the heat loss calc they did. But, they assumed there was some insulation in one floor where there was none. They installed the UFH and told me not to bother insulating it so how that happened is beyond me. That was a 1Kw error. But, there should be enough fat in calculation to still be ok. But it’s not

ReplyQuote

Page 2 / 2 Prev