These plants prefer a very sunny spot, and flower better in years when we have hot summers. Yours is on a west facing wall, so won't get as much sun anyway. However, you don't say which Campsis it is, nor what the size of the pot is - as its a climber, it needs a large pot for its roots. If its Madame Galen or similar, prune in February, and in March, topdress the pot with some sulphate of potash, and stir it in, then again in April.

may I add it might be down to the fertilizer, to much nitrogen will produce groth of folage at the expence of flowers, this is added to what Bamboo said not insted of you might try some bloom booster from your garden center

That's what the sulphate of potash is for, Cliffo - it encourages flowering

thank's Bamboo,