by Perry525 ?? Tue Apr 30, 2013 7:22 pm I know this is old.Concrete or brick are the best things to use for storing heat.In one of my houses I had thermostat controlled gas fires that were on 24/7, that was before I installed my own skirting board heating system.When it came to making the change over, the brick chimneys kept the house warm for four days.It turns out that concrete has one of the hi