downpipe smelling of ammonia

[rward74]

I have a brickbuilt lean to in which my downpiperuns through, recently my outside drain was blocked and was cleared by a council approved contractor. He told me that we might be prone to blockages due to the fact that the sewer had a ubend drain with a access clearing straight pipe. he also told me that this clearing pipe should have a cap on it. since having it cleared there is a accrid ammonia smell in the brick built lean in which the downpipe runs, is this because there is no cap on this pipe and if so is it difficult to install, i really need you help as the tumble dryer is out there and my wife is refusing to go out there and dry my shirts

 

[Nige F]

that`s an interceptor trap and 99.9 % of them in the country have the bung missing . Try resealing the manhole lid with some heavy grease Ammonia could be a cat creeping in