Gloucestershire,
United Kingdom 
Have two rows runner beans have grown well but produced hardly any flowers. One variety "Enorma" the other "Scarlet Emporer". Not a case of flowers dying off but just didn't develop on stalks. See photo's.
Can't detect any pest which may have eaten tips though suspect it might be cause.
29 Jul, 2014
Have noted comments made in website regarding soil structure and shade. Suspect both have contributed as well as dry spell soon after plants were established. I live in hope we may yet get a bean to grow!
2 Aug, 2014