Hi all, this is my first message. Well i had a fault with my boiler. when it stopped running it did so with a vibrating noise, it then carried on firing up and shutting down with the same noise on each occasion. after several cycles it whent into fail safe with a slow blue flashing light and reset light. A quick general look at the condeser outlet trap showed a lot of grey/black crap inside. I gave the black rubber connecting pipe on top several squeezes and this caused the filter to siphon out and suck a load more crap down out of the heat exchanger area. I then removed said clear plastic unit, flushed it out, refitted and now all is fine. Fault caused by dislodging sludge after draining heating system and refill.