What you could do is switch Heatran out with Lanturn and then Talon flame with Noivern. The only problem with this is you would have to switch Rotom Wash for something else (I have no idea what), maybe something with a rock resistance. Anyway here are the movesets I would use for Noivern and Lanturn I would use.
Lanturn @ Leftovers
Ability: Water Absorb
EVs: 252 HP / 4 Def / 252 SpD
Calm Nature
- Volt Switch
- Scald
- Heal Bell/Roar
- Thunder Wave/Toxic
Noivern @ Choice Specs
Ability: Infiltrator
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Draco Meteor
- Air Slash
- Flamethrower
- U-turn
You could substitute Roost for either Flamethrower or U-turn if you wanted.
Hope This helps!
Doesn't exactly help here.
What does Lanturn accomplish over Heatran? What does Noivern accomplish over Talonflame? Talonflame is in here to provide revenge killing utility.
I don't think Noivern is suitable for this team because it's not that strong. If you want other Water resists on the team, try out Dragalge (while it has Noivern's Special Attack, it has Adaptability to compensate for its lack of power). Heatran should stay because it provides crucial (backup) Dragon and Fairy resistances; Excadrill shouldn't be relied on to deal with them.
Anyway, here's the Dragalge set if you're interested:
-Sludge Wave
-Draco Meteor
-Scald/Hidden Power (Fire)
-Focus Blast/Hidden Power (Fire)
Nature: Modest
EVs: 200 HP/252 SAtk/56 Spe
Item: Choice Specs/Dragon Fang/Poison Barb/Toxic Plate/Draco Plate
Ability: Adaptability