The Misquote That Ruined the Heating Industry

Talk to a multitude of influencers, policymakers and heat pump salesmen in the UK, and it’s easy to find common ground. They all think heating should be as easy to use as flicking a switch, responding to clients’ expectations of thermal comfort. They say, “The client is always right!” Any attempt to explain that thermal responses to ambient temperature and building heat take time, and that boosting functions and tinkering with thermostats make the system inefficient, are shut down. Many of you are probably nodding your heads thinking, “Yes, the client is always right, damn it.”

But here’s the thing: the original quote by Harry Selfridge in 1909 is actually, “The client is always right, in matters of taste.”

And here we are in a technologically advanced country allowing a relay developed in the 1940s to control our state-of-the-art, highly efficient heat pumps because so many of our engineers couldn’t be bothered to read to the end of a quote! I sympathise with manufacturers who say their complex installation instructions are rarely read.

The irony, of course, is that heat pump controllers do exactly the same as on/off relay controls, but in a different, often better way:

• Temperature Adjustment: You can turn the target room temperature up (just like a relay control), but because there is less power than in a (usually) oversized boiler, the system takes time to raise room temperature. So it’s probably best to just accept one stable temperature.

• Setback Periods: You can set time periods for comfort and setback temperatures. If your setback is set low enough, radiators will shut down and get cold (just like a relay control). But why do this when setback avoids long waits to heat ambient temperatures to acceptable levels?

• System Shutdown: You can turn the system off (just like relay control), and the system goes into frost protection mode and exercises moving components such as pumps and valves to avoid seizure during inactivity. Surely you want this!

Constant variable levels of heat in radiators or floors match heat loss of buildings, maintaining stable room temperatures that enable high efficiencies. Paradoxically, because there are no temperature swings, people can get used to lower ambient temperatures, starting a virtuous circle of energy efficiency.

It is often pointed out that higher efficiency doesn’t necessarily mean less energy used, but judicious use of the controller will enable optimum usage of energy that will likely use less energy. And frankly, if people want to save energy, they can just turn down the set point temperature or put on a sweater.

Complexity of interfaces is routinely cited as an argument against heat pump controllers, but this raises a question: Why are people tinkering? If a good heating system delivers a stable room temperature (are you really going to argue for unstable temperatures?) people adapt to new interfaces regularly. Cars, TVs, sound systems, etc., all change regularly. Yet, I have heard our own industry experts argue in defence of keeping the same thermostat installed circa 1980 on a heat pump.

So why aren’t manufacturers educating their staff, installers and homeowners on optimum settings for heat pump controllers? To put it bluntly, it’s a cost issue. Anyway, you can always use an on/off relay thermostat, and the system will do what you expect, leaving the hapless installer to pick up the blame for a failing installation – a virtuous circle for the manufacturer.

Engineering-led policymakers in other countries effectively removed on/off controls from the market with enlightened regulations. In the UK, the enhanced capabilities of heat pump controllers were never fully appreciated (despite being developed at Glasgow University in the ’90s). To this day, you can still buy the very same thermostat developed over 80 years ago.

People are happily told what to install and where when building or renovating a property (fans, windows, smoke alarms, etc.). But when it comes to heating, it’s a free-for-all.

And like it or not, that has to stop. So policymakers, influencers, engineers, installers, salespeople and yes, even homeowners, let’s rise to the challenge and spread the word about the benefits of using just the heat pump controller. Heat pump and control manufacturers, do the right thing and stop selling technologies that don’t optimise systems. Start sharing information in an understandable format about your state-of-the-art controllers that actually optimise them.