Comment: Initially the wrong type of unit was sent to my location- a non-truck unit. This could not do the job because there was no hot water available. However, dispatch immediately scheduled the right service for the same appointment period time and the technician arrived during the stated time period. This technician, Jamie, is very thorough and efficient. I highly commend him for his demeanor and work.
As to solving the problem about what type of unit to dispatch, online order site needs to have questions about this.