My wife has set the temperature knob on our gas AGA to give known temperatures in the various ovens.
We noticed that yesterday a loaf of bread was slightly overcooked compared with the normal 20 mins in roasting oven plus 10 minutes with cold shelf (heat shield) above the loaf. The temperature gauge on the AGA was reading a bit higher than normal.
The weather was very windy. Could it be that wind blowing across the top of the flue pipe was creating more of an updraught than normal, making the gas flame burn hotter? If so, wouldn't the thermostat (set by the temperature knob) have corrected for that?
If we'd thought, we'd have measured the temperature in (for example) the roasting oven to see if it was hotter than normal.
Gas usage for the house was a bit higher than normal: about 105 kWhr rather than about 95 kWhr which it has been averaging recently, even though the outside temperature was warmer so the central heating wouldn't have been on for as long. (Yesterday the boiler was on for 2 hr
2 min, compared with 1 hr 58 min for previous day, so CH usage was very similar. Figures courtesy of Hive.)