Hi All, my first post and I'm a low-rank DIYer I'm afraid, feel free to slag me off!

I self-installed a couple of chineese cheapo systems off ebay, R407C, working a treat for past couple of years.

Now I've got a 2.5kW Summit Inverter, bought with flexible lines and quick-couple connectors at the outdoor box - installation was nice and easy - but it worked superbly for exactly one day, now the compressor won't start and the timer light is flashing 4 times on the indoor unit.

Supplier seems relaxed enough about it, but are these units generally unreliable?

Thanks!