An obvious candidate would be blocked drains from the heater intake plenum. Water runs down the intake, cannot drain fast enough and ends up going through the heater into the footwells.

Could be crud in the drains themselves or just leaf matter in the plenum blocking them.

Many thanks indeed for your help and reply, unsure who to address my thanks too,

If your TeeCee again thank you," I'm sorry to ask and take your time again" would the location area where the blockage has formed is this to be found beneath the grill that followers on from bottom of windscreen to start of the bonnett.

Once again many thanks in advance