Simple then, the normal temperature thermostat is faulty so the over temperature stat is catching and tripping out, hence you have to reset it.
Solution used to just as easy which was replacing the normal temp stat; however Truma are no longer supplying them and their specials so not available from anywhere else. Least I've not to date found anywhere.
Best bet then is possibly to ring round dealers in the hope someone's got one on the shelf?
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