Now push it down with a very SMOOTH very QUICK motion
That's the key on a mechanism which is starting to wear a little. You have to remember that the standard U.K. flush system is quite different from the one used in the U.S. It consists of an up-and-over siphon arrangement, like this:
http://www.screwfix.com/app/sfd/cat/pro.jsp;jsessionid=?cId=100996&ts=39696&id=44047The handle operates a diaphragm which lifts the water and starts the siphoning action. When that diaphragm starts to wear it becomes more difficult to start the flush -- A really worn-out diaphragm can reach the point where you can only start the flow by either pressing down
very sharply or by pumping the handle several times in rapid succession. (It has to be
very worn out to reach that point!)
So if you start to have trouble with the flush, it's time to service the cistern. As I mentioned above though, we have just started to see flapper valves appear on the market here in the last couple of years in place of the siphon. These are the same arrangement as in the States.
Just to complete the picture, you might still come across a very old high-level cistern with chain pull which operates on a slightly different system again. Some of these old high-level units had a kind of bell arrangement, and the flush starts when you
release the chain, not when you pull it! They're fairly rare nowadays, but you'll still find them in old houses occasionally.
Is there a way to do that for just the sinks?
There's no simple adjustment which would let you reduce the hot temperature for the sinks while keeping it high for the bathtub, washer outlet, etc. You can set the boiler or immersion heater thermostat right down, but obviously that will limit the temperature at
all hot outlets.
It's possible to fit a thermostatic mixing valve to an individual bath/basin/shower. The hot outlet from the valve can feed either a separate hot faucet or the hot side of a mixer tap, as required. These valves are commonly used in care homes, schools, etc. these days. You set the required maximum temperature and the valve automatically mixes in a small quantity of cold water as needed to limit the temperature.
http://www.screwfix.com/app/sfd/cat/pro.jsp;jsessionid=?cId=100121&ts=39741&id=18732