Yes it might! Depending how you define "IT"!
Have done things similar and it works, though detail and function would depend on the specific system, and what you're trying to achieve.
What (I think) you want is that when the "HW" is switched on, the circulation from the boiler is pumped.
The pipe from the boiler up to the top of the cylinder's primary inputs is often the route the vent takes, so you can't interrupt it, but you can put the pump in the return. That's usually the lower pipe.
There's no point pumping cold water round so put a pipe thermostat on that rising/vent/top pipe from the boiler. Also put a thermostat on the cylinder.
For just improving an existing system, take a wire from the HW ON at the programmer, which will be the same as the "on" at the boiler (if not then yell), through the pipe stat and the cylnder stat, to the pump.
So the pump only comes on
If there's a demand for HW
and if the primary pipe is hot
and if the cylinder isn't hot enough yet.
That's just one of several possibilities. If there's already a cylinder stat then you should be able to use the live feed to that. If there are no wires going to the airing cupd from the programmer/boiler you can still do it by getting power locally - on a timer if you want.
Note that the water will still get hot by gravity circulation whenever the boiler is on (ie when the heating is on) so doesn't satisfy building regs for a new system.
If you can get wires where you want, you can use a system like Honeywell A plan to turn the boiler off if the ch is off and the water's hot enough.
if you want a modern system do what DIA says!
