I REQUIRE A TIMER THAT WILL LOOK AFTER 220 VOLTS FOR A SMALL WALL BUILT IN ELECTRIC HEATER SPRING LOADED 30MIN

You want spring-operated 30 minute countdown timer for 240Volt electric heater.
You don't say how many watts your heater is.
Answer is longer without knowing watts.

1) As you know, you can turn off any 240Volt circuit by turning OFF one hot leg.
http://waterheatertimer.org/240-v-water-heater-circuit.html#120-240
People are skeptical when working with 240 V and believe both hot wires have to be turned OFF.
But you know the heater needs both hot wires. Disconnect one hot wire and see.
240V water heater thermostats operate in this way ... they turn OFF 1 hot wire.

2) Intermatic FF30 and FD30 series timers can directly turn off 1 leg of 240Volt 2500 watt heater.
Max 2500 watt, no more.
This Intematic timer is rated for wattage shown. With other brands, check the rating.
Amazon sells FD30 30-minute
http://www.amazon.com/dp/B00004W4WW/ref=sc_vs_google_Intermatic_2520FD3

3) Intermatic also makes DPST timer if you want to turn OFF both hot wires
Aplussupply sells FF and FD Intermatic timers, and 30-minute DPST model FD430M
The rating is same as shown above.
http://www.electricsupplyonline.com/prod/intermatic-springwound_timers.php
http://www.intermatic.com/products/timers/in-wall%20timers/decorator%20spring%20wound%20timers.aspx

4) If your wattage is greater than 2500 watts, then you need to install a 30amp contactor with 120Volt coil. Timer turns magnetic coil on-off, coil opens and closes contacts that turn heater on-off. You can use any ordinary light-weight wall timer with a contactor.
http://waterheatertimer.org/Countdown.html

5) Following page gives you information for installing a contactor to handle 240Volt loads up to 5500 watts.
Pages show how to wire, where to buy, what to buy.
http://waterheatertimer.org/How-to-install-water-heater-timer.html

Add a comment for more free help.
Also take advantage of fixya phone service.
For a price, expert speaks with you over phone while you work on timer or any do-it-yourself project.
Fixya is always less expensive than a service call.