What a good idea for a thread.
Just an addition to your comment:
During this cold spell if you find the central heating will not fire up then check the condensate pipe particularly if it is on an outside wall. If it has frozen then the boiler may not fire up. To fix get a couple of jugs of hot water and pour over the pipe to thaw it. Much cheaper to check this before you pay for call out charges as it only takes a couple of minutes.
Once you've thawed out the pipe, you may have to reset/restart the boiler. This is different on all boilers but modern ones tend to have a power switch that you can hold down to turn it on, and then again to turn it back on. Older ones may require power cycling via other means (isolation switch or similar).
Bleeding your radiators can make a big difference, especially if they haven’t been done for a while.
Be aware that after bleeding the system, you may need to increase the water pressure in the system. Most modern boilers have an inbuilt filling loop, and older ones tended to have this separate. Familiarise yourself with the setup of your system before you bleed out the air, otherwise your boiler may shut off due to low water pressure with no knowledge of how to increase it again.
On that note, if your water pressure has dropped since you last looked and you haven’t bled your radiators (and the system is at the same temperature), this may be indicitave of a leak, or a failing expansion vessel. Both of these would be best left to a heating engineer unless you’re very good at DIY (and then this thread likely isn’t telling you anything new).
And finally a simple one: if your electricity goes off, your gas boiler and heating will do too. All systems require electricity to pump the water around, ignite the gas, and run the controls (timer/thermostat). Not much you can do about this aside from check that the boiler is working again once the power comes back on.