Warranty terms for Solar PV installations

[UrgeToSplurge]

[font=andale mono]We have a 3.92 kWp solar PV installation, with independent inverters, one per panel.  The reason for that choice was that even though it cost more up front, the failure of a single inverter only affects one panel, not all of them.

Recently, one of the inverters failed, and so we contacted the installer to replace it under warranty.  They in turn got in touch with the manufacturer, who have supplied a replacement inverter to the installer under warranty.  Unfortunately, the installer tells us that the [i]labour charges[/i] associated with replacing the inverter are [b]not[/b] covered under that warranty  >:(, and want nearly £350 to do it.  Our cost-benefit analysis of having solar PV was on the basis of the installation being under warranty for the lifetime of the system (25 years), so this information runs counter to that.  Is this usual practice in the industry?  If so, this is misleading and undermines the economic case for domestic solar PV.[/font]