Your Arros controller may be telling you to purchase the wrong lamp!
Please continue reading below for more information.
The Viqua Arros UV systems come in three different sizes: the Arros 9, Arros 15, and Arros 22 and each of these systems has a unique replacement lamp (VA09LU, VA15LU, and VA22LU). When an Arros system is installed, the installer needs to "tell" the controller what system it is being used with (the 9, 15, or 22). If the installer does not do this, or does it incorrectly, when it is time for a replacement lamp the controller my suggest the wrong replacement. We are seeing this quite frequently.
Before purchasing a replacement lamp, please double check which one you need. There are two ways to do this:
1. Check the label on the steel chamber:

2. Check the steel chamber length:
The following chart shows the system model name, corresponding replacement lamp number, and the length of the steel chamber for each system. If you can't read the sticker on the chamber, or have any doubt about which replacement lamp you need, please use the steel chamber length as your primary guide:
| Model Name | System Chamber Length | Replacement Lamp |
| Arros 9 | 11.2" | VA09LU |
| Arros 15 | 16.5" | VA15LU |
| Arros 22 | 22.5" | VA22LU |
The "chamber length" for a Viqua Arros system is shown in the image below. Use this chamber length as a double-check to know if you're ordering the correct Viqua Arros replacement lamp.
