I have a Raypak C-R336A-EN-X ASME heater on my 30k gallon IGP. This is a Raypak Digital 336, ASME, commercial with Cupro-Nickel Heat Exc. I've only owned the pool for 2 seasons so I don't know the age of the heater. I had a slow leak at the outlet joint at the end of the swim season and I just took it apart to repair the connection. I noticed quite a lot of corrosion in the cast iron header when I removed the outlet pipe. I've noticed similar corrosion in the cast iron return header on the opposite end of the heat exchanger. I've also seen rust flakes come out of the return jets into the pool. So obviously the headers (at least) are corroding. My question is whether it is worth it to buy replacement cast iron headers for both ends of the heat exchanger (probably ~$500+ in parts based on quick online search)? Or is it time to replace the whole heater? I'm fairly confident I could replace the headers myself with the right parts, but I'm not sure whether other parts of the heater will start to fail in the near future. Anyone have experience with repair of this heater?