I’ll check out the inverter in morning.
Ultimately the installer has got to take some responsibilty, as it was working fine prior,whether that is 50:50 with free installation or you pay for the inverter and he installs it for free. Ultimately, I prefer the former option, as fairness all round but, what ever you do ensuure its written in the contract/final invoice, thus providing a solid warranty for future reference. I would also gain some proof that if a new inverter is the go forward plan and it doesn’t work due to some other fault or problem previosly stated, the installer takes full responsibility for any costs incurred! If it were me, I’d be cchecking and fault finding my work before proceeding, ensuring nothing silly is causing it to not power up.
Take a look at this Solis fault finding guide, which explains in detail what I’m trying to get across 🙂