The dryer is 1 year 5months old
all the lights were flashing along the top row altogether.
I turned it on to make sure which lights were flashing and lo and behold, the dryer is functioning fine.
Presently drying my work clothes!
Could it have been that the dryer was overloaded?
That makes sense if it is the belt / pulley as it was a large load and it seems to be going ok now. I will monitor it and see what happens. I can mend it if the pulley / belt needs replacing.
Thankyou for your input. I'll let you know if that is what it was( if it decides to play up again)