Dometic Fridge - Water Drain

Hi Everyone,

Just tried the fridge in the van on gas for the first time yesterday and have a question in regards to the water drain that releases any condensation the fridge generates, it runs through what appears to be the heating element and you could smell a plastic burning smell when it was on, when I had a look afterwards the pipe that was white is now slightly yellow/ brown with discolouration which I think might be from it getting hot.

I also only had it of for an hour or so to test it and I am worried that if I leave it on for a long period of time that it will melt. Has anyone experienced this or something similar before with a dometic 3 way fridge or is it normal?

Thanks again for all your help.

Sherron