How many LBS of Malt is going into your all-grain mash?
Depending on the volume of malt, you may need add more water to the mash to hit your temps
i.e. on a Stout I recently had 9# of Malt and started with 3.5 gallons at 130degF. I then added 1.25 gallon of water at 200 degF. I hit 150...
In my last batch of home brew I used about 13-14# of Malt and 4oz of Hops (Plug style).
2-1/2 gallons of mash water and 1-1/2 gallons added to the mash. 3-1/4 gallons of sparge water.
Hope this helps