Its in the Known Error codes thread, page #4. F13= rear NTC open or short circuit. Some have two stats plus NTC some just one stat and NTC. You should always replace the lot and make sure the condensor is clear.
there is 3 in the back but iv not come across this machine before what is a ntc will it come in a thermostat kit i tested all and one is ok the other 2 are gone is that the ntc thats ok