I'm in a small flat with an old Biasi combi boiler. Currently I have an ancient electric shower that is absolutely pathetic - I have measured the flow rate at around 2.8 l/m of warmish water.. I'm wondering how much better a shower I could expect from a thermostatic mixer fed by the combi boiler. A possible issue is that due to overheating problems when the central heating is on, the effective output of the boiler has been dialed back a bit, so it's not running on all cylinders. The boiler engineer who adjusted it mumbled something about t*rd polishing.. ;-) When I run the hot tap in the bathroom sink at maximum the flow rate is about 7 l/m (the flow rate of the cold tap is about 13-14 l/m). The temperature of the hot water at 7 l/m is about 40C when the cold water is around 8C (so I guess the boiler output is 7 l/m for a 32C rise?). This might seem obvious, but can I assume that the output in l/m from a thermostatic mixer shower will be much the same as from the hot tap in the bathroom, at least if the hot shower tap is fully on? In which case it would be 2.5 times as good as my current electric shower at least? To me this would seem like a massive improvement, but reading around I get the impression that 7 l/m at 40C wouldn't be considered a good shower by most people.. And I'm worried that the flow rate from the shower might be less than from the tap for some reason I'm not aware of. Or would I be better off with a really good new electric shower?