Three weeks is pretty good for a specialised unit that wasn't in...

Three weeks is pretty good for a specialised unit that wasn't in mass production last winter. The unit would have needed to be checked by someone from CFU, then quite probably a new part would have needed to be fabricated. Then it would need to be installed and checked. This isn't a bog standard boiler or hydronic heating system! There may have been some time required to diagnose the fault.

Because we now have Jabil on side as the manufacturer for all of the Bluegen except the fuel cell itself, the turnaround for parts will be much shorter. And as utility companies come onstream, they will train up a servicing network. I would expect servicing times to drop.

Living in the UK, I once had problems with my boiler and heater, it took 2 weeks to fix.