Question's been puzzling me all summer, now I need to turn the heating on... so if anyone knows...
I have hot water underfloor heating powered by a diesel heating/hot water furnace. The floor takes around 5 hours to warm up as the pipes are under a 6cm slab of concrete with stone floor tiles on top, it also takes around 5 hours to cool down again. I have programmable room thermostats in each room controlling that room's floor.
If, for the 5 hours it takes for the floor to heat up, the thermostat is telling the furnace "more, more, more!" surely at the point the thermostat finally says "OK, 22°C, turn off" the concrete slab is still loading itself up with heat. Is it not the case that the floor will continue to get hotter 23°C...24°C... 25°C... for an hour or so more until starting to cool back down again? Then on it's way down it trips the thermostat again but continues to cool... 20°C...19°C...18°C... until the slab can warm up again - and we're back in the "whoa, too hot! Brrrr, too cold!" cycle?
Or is this not the way hot water undefloor heating works in practice?
-- SL