Cause of rusted heater?

[cmcq]

Thanks for all the replies. For some reason I didn't get notified when they were posted.

Anyway, here is what I know and what I don't.

When I open the heater, all the metal parts I see are rusted. The pan on the bottom, the outside of the gas line, some of the sheet metal that seems to house the pipes and heater mechanism, etc. I don't know if the rust was caused by water than leaked out of the plumbing/heater, or another source (rain?). Given how widespread it is across the inside of the unit, it would have to be a lot of water but some of it could have come after the big leak which was causing the pool to lose pressure.

In the past few years, I've had problems with metal stains in the water and had to consistently put metal binding agent in the water and/or the vitamin C treatment. Since the heater has been removed, I haven't had any issues with metal stains. If it is related, that could indicate some issues inside the pipes, right?

I can't pinpoint the leak that led to the final demise of the plumber.

Thanks to PoolDoc's comment, I located the Pentair manual and it says clearly "These heaters are designed for the heating of swimming pools and spas, and should never be used as space heating boilers, general purpose water heaters, in non-stationary installations, or for the heating of SALT WATER." I'm going contact the miserable, greedy, lousy pool company who installed it and go back at them (although I have very low expectations with that).

Assuming that does nothing for me, I'm getting estimates on new heaters. One is the RayPak - Digital Pool Heater P-R406A-EN-C Natural Gas, and the other is an un-named Hayward heater (I'm getting the details next week). Both quotes are around $3100 - ouch. Based on chem geek's suggestion, it appears I should ask for the cupro-nickel or titanium, which I suspect will drive the price up further.

Any final thoughts from the group (and thanks again)
Charlie

[Pool Clown]

A Layer of rust throughout, as you describe, suggests that the rust may have come from chems stored in close proximity to the heater (in the same room).
Or...
A pin hole leak that acted like a mister, and kept the area in question not so much wet, but humid.

The absence of metal stains after you removed the heater suggests a possible chemistry problem.

Raypak heaters are great heaters IMO, i think you will be happy if you choose them.