Ok I'm missing the basics - do you have to amend the main code to include a statement to look at the bootloader ?

Here's the first few lines of the main program code as requested

Code:
INCLUDE "Hardwr_4580.pbp"
DEFINE WRITE_INT 1                                                                                                         
INCLUDE "DT_INTS-18.bas"                        ; Base Interrupt System
include "AM2302_LIB_v024.bas"
ASM
INT_LIST  macro                                 ; IntSource, Label, Type, ResetFlag?
        INT_Handler   TMR1_INT,  HeaterDrive,   ASM,  yes
        
    endm
    INT_CREATE                                  ; Creates the interrupt processor
ENDASM

T1CON = %00000001                               ; free-running, 1:1 prescaler
@   INT_ENABLE   TMR1_INT                       ; enable Timer1 interrupts

ENABLE DEBUG

;----[DS1820 Options]----Value----Default-----------------------------------
DEFINE  DS1820_DECIMALS    1                    ' 1
DEFINE  DS1820_VERIFYCRC   YES                  ' NO
DEFINE  DS18B20_ONLY       YES                  ' NO
INCLUDE "DT18x20.pbp"                           ' Include DT18x20 module

;----[Analog Settings]------------------------------------------------------
INCLUDE "alldigital.pbp"

;----[PID multi-channel]----------------------------------------------------
PID_Channels CON 4
INCLUDE "incPID_mc.pbp"                         ' Include the multi-channel PID routine.

;----[Port settings]----------------------------------------------------
TRISA = %11001111
TRISB = %00000000
TRISD = %00001111
CMCON = 7                                       ' disable Comparators
ADCON1 = $0F  ' %0000 1111 AN2=VSS, AN3=VDD, AN12-0 = Digital 
ADCON2 = $00  ' %0000 0000

;----[AM2302 ]----------------------------------------------------------
AM2302_MAX_SENSORS con 4  ' Number of Sensors Used

;----[USART defines]--------------------------------------------------------
DEFINE HSER_RCSTA 90h ' Enable serial port & continuous receive
DEFINE HSER_TXSTA 24h ' Enable transmit, BRGH = 1
DEFINE HSER_CLROERR 1 ' Clear overflow automatically
DEFINE HSER_SPBRG 86  ' 115200 Baud @ SPBRGH = 0
BAUDCON.3 = 1         ' Enable 16 bit baudrate generator

RCSTA = $90   ' Enable serial port & continuous receive
TXSTA = $24   ' Enable transmit, BRGH = 1
SPBRG = 86    ' 115200 Baud @ -0.22%
SPBRGH = 0
BAUDCON.3 = 1 ' Enable 16 bit baudrate generator