Hello, Newbie, but have searched posts and need some advice. Moved into a refurbished house over the summer with a new Biasi ActivA boiler (still under 5 yr warrantee). Boiler has been working fine until this weekend. First on Friday night, boiler stopped working, and on investigation, the condensate pipe (32mm) had frozen. 20 mins of pouring warm water resolved the problem. Boiler worked all night and throughout saturday. Woke up a 3 am this morning with boiler on, and making loud banging noise and shuddering. The radiators were not warm. I turn everything off, and checked 30 mins later , initially with hot water and then with c.h system. We get hot water, (boiler shudders twice and then continues working). As soon as turn up the roomstat for heating, the banging and shuddering is on continuously. I have turned the boiler off.. I tried to call Biasi, but they are not open today and will have to log a call with them tomorrow. My questions are: 1. Are there any simple checks, that i can do. 2. Can i do them without invaliding the guarantee and breaking the law (I am not gas safe registered), but competent with DIY. 3. would the frozon condensate have caused the current problem. Looking at other posts it sounds like the pump or heat exchanger clogged up. I can see a sticker for Fernox inhibitor on the boiler. Could the heat exchanger clog up in 6 months (i am in the midlands). Any advise would be welcome, as i don't fancy spending a day in an unheated house with 2 young kids!