Pentair 474061 Tube Sheet Coil Assembly Kit; Cupro Nickel; For Model 400NA; 400LP MasterTemp(R) Heater
This part fits the newer-model (post 2013) tub design. If you're not sure what you have, check the lid for the tub, if it's held on by a clamp, then it's the older design, the new design has 9 bolts holding the lid on. Much easier to assemble/disassemble. Not sure what the difference in the coil assembly is. But this dropped into place in my unit (2019) with no issues. And this is a fairly easy DIY job too that requires minimal tools and a couple of hours to complete.
Quite a few extra parts came in the box too, like a big o-ring for the old tub design, all those square metal parts for the burner system, and extra metal shield piece (one is attached to the coil) plus the red silicon RTV is not needed either for the new tub design. This must be a catch-all kit for all models. The only thing you need is the coil, the pads and the o-rings. They did not supply any silicon grease for the o-rings (like the manual said), so I took a shot and installed them dry and had zero leaks, so it worked out. Appreciated getting a new igniter too, I broke the original one trying to drop the tub lid assembly through the little hole in the pads and busted it clean off. Recommend removing the igniter, installing the lid assembly, and then installing the igniter. It's super fragile.
Also, the manual is extremely helpful. Follow the instructions, there is a torque pattern and torque value for the 10 bolts that hold on the manifold assembly. Don't miss this step. Also the way the pads are installed is very specific. Overall EZ did a great job shipping, box was packed well but saw some damage in transit, parts were all fine though. Saved me thousands over having Pentair do it. Warranty is totally void now but that was voided the second we let the pool eat away at this coil assembly due to low pH. Learned my lesson, don't let your pH get too low if you have one of these heaters. They will get destroyed and Pentair will not cover it. Thanks a lot EZTest for getting our hot tub back up and running. We've used it half a dozen times already and everything is working great so far!