Water Heater Saga

Nate bought a tankless hot water heater booster through Kickstarter ($250). It finally came in almost a year after promised. We called a plumber to install it and they said we had to get an electrician to install a new circuit breaker first ($200).  Then we called the plumber back and they installed the unit ($200). It didn't work so we called the plumber back and he said it was because we needed to get the electrician to come back to finish the electrical installation ($75). It worked... for 2 days. Now it's not working again so the electrician is coming out again tomorrow...