Actualy, those heaters will get the water to near boiling. That's why I had to set them on a brick.
The main problem I've had with pumps is when they got sludged up with the dust from the tile cuts. Before I got the Dewalt saw, I always had a set up where the pump was in a clean bucket of water and the dirty water drained out into another bucket. Once I stated doing that, the pumps lasted a long time.
The dewalt tray has a separate compartment for the pump, and it keeps most of the dirty water out.
Speaking of Dewalt saws, my local tile store has them on sale for $809 with a stand. That is about ~550 GBP.