you will need to order thermostat kit: 1701557. Red spot from here:
http://www.cesexeter.org.uk/product_info.php/products_id/80
Make sure the colour is correct otherwise it is a safety hazard.
the heater element where the thermostats are located is behind the cover in the middle. take the wires off and one screw and the thermostat will come out. write down where the wires go before doing this.
Ben, June 2006
