Will my gas pool heater corrode if I empty my pool?

[macman]

We will be resurfacing our swimming pool this coming week. To do this, we must completely empty it. A gas heater is used to warm the pool during winter.
When we empty the pool, water sitting in the gas heater and its piping will drain out into the pool. I am concerned about possible corrosion within the heater due to oxygen causing corrosion inside the water pipes of the heater.
Is this a concern, in your opinion?
The pool will not likely be refilled for 2-3 weeks.

 

[cowboycasey]

Not worried about the heater at all.. I am concerned about the pool.. Is there any water under the pool? High water table? Just not sure in Australia if you have that to worry about it...