Sorry can't solve your problem but be patient every thing seems to be slower this year, my beans are only just starting to set.they need feeding are you doing that ?good luck

Runner beans are never easy t grow this year they seem to be a royal pain! Just cross your fingers - we don't even have any flowers yet! They are meant to prefer a cool climate but are not playing ball with us!

It should say on every packet of runner beans, "Beans may take some time to set depending on temperatures and the time of the season."
In my 35 years of gardening I think I've heard this question asked every year.
The answer is always to spray the flowers or the plants, but in my experience they will start when they are ready and not before.

how true Bertie :0))

Our runners were doing very well this year hundreds of flowers but worryingly not many bees. Then last week we had a massive rainstorm and the flowers from the bottom half ended up on the deck ! Honestly you cant win with beans all you can do is water them lovingly. Yesterday we had our first picking - 10 runners between two of us.Ah well have to hope for the best !

I've been watering my beans with a tube fitted with little spray nozzles (Gardena type) putting this on for about 15 minutes a day. I've now got the first really successful crop of runners I've grown here since we moved (where it can be very hot and dry in summer). I think adequate water must be the solution to many of these flower drop problems, though mine were dropping until a week or so ago. The plants are now covered in young beans though, and I expect this will be the experience for all those with early flower drop problems very soon.

Thanks to all who tried to solve my flower drop on runner beans,
I am now getting a few pickings, three meals so far but still very sparse,I think Bertiefox you have the answer, water lots and often,i to have purchased a ten metre length of irrigation hose[ a pound at the poundshop] i have laid it in the centre of my flower bed,really brought them on,I am going to purchase a length of soaker also and try that.

Frankly you are lucky we haven't even got flowers yet - beans over 2 metres high - I think they are just having fun with us...