There's an acid test that we as engineers should always subject our creations to: do they make life better for the end user? "Better" is perhaps quite difficult to quantify, but you can always approach the problem from the opposite direction and see if you've made things worse.

This is something British Gas's man clearly failed to do when fixing my grandparents' central heating recently. I don't know the full details of the problem, but I do know that their thermostat was broken, so he installed a new one.

Fair enough, but it turns out that the iron march of progress has changed a thermostat from a knob with some numbers on it to something 'smart':

Central heating thermostat, circa 1990

Wireless super-blingy modern thermostat, circa 2011

And how does the new wireless thermostat make life worse for my nonagenarian grandparents? Let us count the ways:

  • Because it's wireless, it has batteries in it which need replacing every so often. This is achieved by opening a flimsy plastic door on the bottom of the unit which is fiddly to access once it's wall mounted, then scrabbling on the carpet as the batteries fall to earth. It also means the thermostat will mysteriously stop working once every n months until someone younger sorts it out for them, since there's no way they'll hear a low-battery beep or spot an indicator on the screen.
  • Since it's superglued to the wall just inches away from the hot water tank it controls, the only advantage of wirelessness is to save the drilling of one hole and the running of a six-inch bit of cabling - and even these could presumably have been avoided by replacing the original thermostat instead of leaving it screwed to the wall but not doing anything.
  • Instead of reading the numbers round a knob, you see them on an LCD display which is not backlit and not very big, thus making it perfect for people with poor eyesight to see in a not-very-well-lit hallway.
  • Pressing the middle of it resets it to a pre-programmed 'preset temperature' ("ideal for the poorly sighted", the manual claims with no sense of irony) - an unnecessary recipe for confusion if you knock the middle by mistake
  • It doesn't go 'click' as it passes the current room temperature like an electromechanical thermostat would, so you have to read the screen instead
  • By default the display shows the current room temperature, meaning you can't tell without adjusting the knob what temperature the thermostat is currently set at

Somewhat more subjectively, I think it's more likely to malfunction than an electromechanical device with two moving parts, and presumably it has to fight for spectrum with all surrounding cordless phones, WiFi units and garage door openers - let's hope the base station does something sensible in the face of losing contact with the unit.

Well done, lads. Another triumph of engineering.