Why will my dryer not work it keeps flashing and says f04

F04 E04 means low power voltage to dryer - check both sides of AC receptacle for 110 to 120VAC on each side to ground - check breaker panel for tripped or bad 220VAC breaker. Only one side may be suppling voltage to dryer.
https://www.6ya.com/callphilipforhelp

This should be in your manual?
F04 Rear thermostat fault Advice: We recommend you call our customer service centre to book an engineer on: 0344 822 4224

The air duct is inside the case.
Try this. If this isn't your dryer run a search on youtube.

http://imagebank.indesitcompany.co.uk/brochures_online/pdf/Hotpoint/Washer-dryers/F078494%20TCUD97B6G%20MANUAL.pdf

http://www.hotpointservice.ie/help-and-advice/error-codes/
which says: F04 - Pressure switch jammed on empty*
You probably need a talented service technician.

did you try to unplug machine fot 5 to 10 mins to reset machine? hopp this works for you

F4, F04 is always door related.

If your lights are flashing, use these codes to pinpoint the error.

These codes are reading from the top neon down.

F01....OFF, OFF, OFF, Flash, OFF.
F02....OFF, OFF, Flash, OFF, OFF.
F03....OFF, OFF, Flash, Flash, OFF.
F04....OFF, Flash, OFF, OFF, OFF.
F05....OFF, Flash, OFF, Flash, OFF.
F06....OFF, Flash, Flash, OFF, OFF.
F07....OFF, Flash, Flash, Flash, OFF.
F08....Flash, OFF, OFF, OFF, OFF.
F09....Flash, OFF, OFF, Flash, OFF.
F10....Flash, OFF, Flash, OFF, OFF.
F11....Flash, OFF, Flash, Flash, OFF.
F12....Flash, Flash, OFF, OFF, OFF.
F13....Flash, Flash, OFF, Flash, OFF.
F14....Flash, Flash, Flash, OFF, OFF.
F15....Flash, Flash, Flash, Flash, OFF.
f16....OFF, OFF, OFF, OFF, Flash.
F17....OFF, OFF, OFF, Flash, Flash.
F18....OFF, OFF, ON, OFF, OFF. Fault on control board, check Eeprom.
these are the codes and this is what they mean

f01 light 4, motor triac
f02 light 3 motor, jammed/ tacho
f03 lights 3&4 Ntc fault
f04 light 2. pressure sw stuck on empty
f05 lights 2&4, pressure sw stuck on full
f06 lights 2&3, N/A?
f07 lights 2&3&4 heater relay
f08 light 1. heater relay
f09 lights 1&4 eprom/setup error
f10 lights 1&3, pressure switch not sensing
f11 lights 1&3&4, pump/draining error
f12 lights 1&2, communication error
f13 lights 1&2&4, dryer ntc/ fan motor
f14 lights 1&2&3, dryer heater
f15 lights 1&2&3&4, dryer heater relay
f16 N/A
f17 light 4, door lock
f18 light 3 comms error (3 phase motor) power board

also try checking this manual
http://imagebank.indesitcompany.co.uk/brochures_online/pdf/Hotpoint/Laundry/WFseries_19504110305_Jan05_book.pdf

my hotpoint washer dryer if flashing f-04 please help

the F04 code refers to improper venting of the dryer.
either your vent is too long, or blocked by lint or a crimp.
dryer vents should be no longer than 10' in flexible venting or 15' in rigid venting.
alot you will find that at the EXIT port outside your house is clogged with lint. remove the lint and you should be ok.

FO4 indicates a pump fault.