Hello and Welcome ! Its still early for Runner Beans ,depending what part of the country you live .I am in the Midlands and have nt got any beans setting yet.But I know from experience that patience is required and then all of a sudden there will be plenty.
Some people mist the flowers with water and say this helps the beans to set.The recent strong wind can blow the flowers off before they have pollinated and birds and some bees even can be the cause, but the Runner Bean will prevail and you will have beans eventually.