Spa O-Ring Replacement

[briannp]

I purchased a spa 3 years ago and the o-rings on each side of the internal BWG heater failed (where the RED circles are) and were leaking badly when the circ-pump ran. I contacted a spa repair company to come out and replace the o-rings. I watched the guy do it, and because there's no flexibility in the system (he unscrewed) the control box, he could barely get the o-ring in place. It still leaks. The repair co said : 'It's leaking because there's no flexibility in the system and the weight of the pumbing is bending everything'. To the right of the control box (the PURPLE box) is external PVCs to an external heater. This configuration was delivered by the company that made the spa. The Spa Company recommended we add a coupling to the left of the control box (the GREEN box), which the spa repair guy thought it would make the problem worse.

The spa repair co seems quite knowledgeable and worked on one from this manufacturer in the past. They want to replace the filter canister and put a flex line to the control box.

Since the spa repair guy is suggesting such an expensive repair on a new spa, and the spa company is suggesting something that doesn't make sense, I'm asking if anyone has a suggestion?

Spa O-Ring repair problem

[CanadianSpaTech]

Says image service unavailable

[Cusser]

I was able to see the image.  I'm surprised that installing new O-rings in the red circles could be so tough, only need to get a small amount of "give" in the plumbing.  I'd also use a little silicone grease or teflon grease on the O-rings.  Did you use a wrench (strap wrench, ViseGrips 12LC) to tighten those large plastic nuts?

https://ibb.co/3WyWXFj