Availability Of Replacement Parts For Nautilus Panel On 2021 Grand Design Momentum 397TH

Updated 12/08/2025 | Published 11/23/2025

Products Featured in This Question

Replacement Dual Diverter Valve Assembly for B&B Nautilus P3/P4 Panels - 1/2" MPT

(26)

$121.89

B&B Nautilus P4 RV Water Control Panel - 12-1/2" Tall x 11-1/2" Wide - Polar White

(18)

$292.90

Question:

I have a 2021 Grand Design Momentum 397TH. I believe this is one of the parts I need to replace in my water system. Do you know what the other parts of the Nutalis system are, and do you carry them? Would it be more beneficial to purchase a new panel? THank you

asked by: Michael

Expert Reply:

Hello Michael, thanks for reaching out. The Replacement Dual Diverter Valve Assembly # BM88GR is for the P3 and P4 Panels, so if this is what you have, you can be sure the valve assembly will work.

We carry the complete Nautilus P4 panels like part # BM54GR. We do have a few various replacement parts for them also, so if there is something specific you are looking for just let me know. Depending how many replacement parts you are needing, it might make more sense to just get a whole new panel. Just depends how much of the panel needs to be replaced. Let me know.

expert reply by: Jesse M

B&B Nautilus P4 RV Water Control Panel
(click to enlarge)

Jesse M.

12/8/2025

Hey Michael, how did things go with the Nautilus panel on your Momentum? Did you end up replacing just the diverter valve or decide to go with the full P4 panel instead? Your update could make it easier for others working on the same water system.