Got this response from HydroHot directly.
Scott,
As a general rule , the fuel stand pipe sets around 6-8 inches off the bottom of the tank , with that being said the Hydro - Hot will stop drawing fuel at a 1/4 of a tank.
Thanks
Bob Turecek
Technical Support Supervisor
Aqua - Hot Heating Systems ,Inc
E-Mail :
bturecek@aqua-hot.com
303 / 857 / 2901 Ext 122
However, I'm below at an 1/8th now and still working. I'll have to ask a tech directly while in Nappannee.
__________________
Scott Crompton
07 Dutch Star 4304
Sue (DW)

Celia 10, Alec 8, Bella (Greyhound), Isis (Abyssinian)