Indesit IDCA735 Tumble Dryer Pump/Float Switch Question

Hi,
I have recently bought an Indesit IDCA735 condenser tumble dryer. An Indesit engineer came out last week to carry out the safety recall mods and gave it a clean bill of health. I then noticed that the drain pump was running constantly so phoned them up to check if this was normal and they sent another engineer. The second engineer spoke to in-house tech support who confirmed this was normal but he re-flashed the control module firmware anyway. I queried what the float switch beside the pump was for and he said that it was to tell the machine when the water tank is full (on my other machine the float switch triggers the pump and the pump stops once the water level drops enough the open the switch).

I have since found a post on another forum that said when the float switch is activated the heating element should cut out and the tank full warning light should illuminate on the front panel. With the rear pump cover removed I manually lifted the float arm to trigger the switch while the machine was running and the machine carried on running, no warning lights illuminated and the heating element seemed to stay hot.

Can anyone confirm, once the float switch is triggered should the tank full warning light immediately light up?

I have checked the switch with a multimeter and the contacts are opening and closing fine. Thanks in advance.