Hello - I have a Pentair Minimax 400 propane heater installed in 2003. I've had some repairs over the years, but appears the time has come to replace. I am going to try and replace the board and module to see if that fixes the service light along with the high temp limits (about $340). But upon closer inspection, noticed the bottom of heater is completely rusted through. The exchanger is fine and pool/spa has been heating fine until last weekend. LPS gave estimate (over $4000!) for the latest Pentair model (Temp Master 400 - #460737) & is pushing this model. Several reviews online with customer complaints though about this unit. TFP searching has many commenting favorably about Raypak heaters. So, I'm researching that. However, not many reviews on the 400 BTU Raypak propane unit (#009227). So, was wondering why Raypak is favored? Division of Rheem. Solid heaters and company? My old Pentair has certainly lasted a long time. Home Depot and Leslie's sells Raypak at considerably different prices, but HD doesn't install. Read that installing yourself can limit warranty, so dilemma continues. I have a SWG and also was considering the "cupro-nickel" or HD models, but many don't think that's needed for residential application and there's lower efficiency with these. My heater is outside on cement pad. Also, read that the Raypak will only control the on/off of heater...and current pool automation allows me to set temp. But if all I have to do is walk over to Raypak and adjust temp, seems that is fine for a quality heater. So, any thoughts or recommendations? My hope is that I can just get a sheet metal panel, lay on ground on bottom of heater above cement, and get current heater working for another year as I prolong the decisions for the next heater purchase. Thanks.