I have a Vaillent ecoTec condensing boiler and when I went to adjust the temperature yesterday I noticed a burning plastic smell. I switched the boiler electricity off, took of the front panel and found that a black plastic pipe had melted (from the manual it appears this is the air intake pipe).
The pipe has melted at two points and appears to have melted from the top so I can only assume that the cavity at the top is filling with hot air? A hole has melted in the 'elbow' at the top of the pipe and the whole of the top of the enlarged section has melted (the enlarged section appears to contain some sort of filter foam, I don't know what it is called).
I am going to arrange a Corgi engineer to repair the boiler but I would appreciate it if anyone could tell me what the possible causes of this could be? I assume he will replace the pipe but I'm worried as the why it would melt in the first place, and whether it will happen again.
Thanks in advance for your help.
The pipe has melted at two points and appears to have melted from the top so I can only assume that the cavity at the top is filling with hot air? A hole has melted in the 'elbow' at the top of the pipe and the whole of the top of the enlarged section has melted (the enlarged section appears to contain some sort of filter foam, I don't know what it is called).
I am going to arrange a Corgi engineer to repair the boiler but I would appreciate it if anyone could tell me what the possible causes of this could be? I assume he will replace the pipe but I'm worried as the why it would melt in the first place, and whether it will happen again.
Thanks in advance for your help.

