Tube Heater Parts Search Already know your model? To get the correct part for your tube heater, you will need the following information.1. Model Series (XTS, HL, DTHS….)2. Date of ManufactureDate code is part of the serial number. Serial Number Identification Serial Number Chart sample burner box tag Model Series DTH Series (40-100 MBH) DTH Ver. [11/86 & Prior]DTHS Ver. [1984 & Prior]DTHS Ver. [1985 to 11/86]DTH(S)-2 Ver. [11/86 to 01/87]DTH(S)-2 Ver. [01/87 to 04/92]DTH(S)-2 Ver. [04/92 to 01/01] DTH Series (125, 150 MBH) DTH(S)-2 125, 150 Ver. [1988 to 1989]DTH(S)-2 125 Ver. [1989 to 1994]DTH(S)-2 150 Ver. [1990 to 1994] XTS Series (All MBH) XTS Ver. [08/99 to 05/03]XTS Ver. [06/03 to 04/05]XTS Ver. [05/05 to 04/08]XTS3 Ver. [07/07 to 07/12] DX Series (All MBH) DX Ver. [01/93 to 05/04/95]DX Ver. [05/04/95 to 09/95]DX Ver. [09/95 to 08/00]DX-2 Ver. [09/00 to 05/03]DX2 Ver. [06/03 to 08/14]DX2 Ver. [09/14 to Present]DX3 Ver. [07/08 to 09/12]DX3 Ver. [10/12 to 07/14]DX3 Ver. [08/14 to 12/16]DX3L Ver. [06/15 to Present] HL Series (All MBH) HL Ver. [01/94 to 05/04/95]HL Ver. [05/04/95 to 09/95]HL Ver. [09/95 to 09/00]HL-2 Ver. [09/00 to 08/02]HL-2 Ver. [08/02 to 06/03]HL2 Ver. [06/03 to Present]HL2-DS Ver. [09/17 to Present]HL3 Ver. [07/08 to 09/12]HL3 Ver. [10/12 to 07/14]HL3 Ver. [08/14 to Present] LS Series (All MBH) LS Ver. [06/00 to 12/12]LS Ver. [12/12 to 2014]LS3 Ver. [12/13 to 10/16]LS3 Ver. [11/16 to 09/21]LS3 Ver. [10/21 to Present] LD Series (All MBH) LD Ver. [06/00 to 12/12]LD Ver. [12/12 to 2014]LD3 Ver. [12/13 to 10/16]LD3 Ver. [11/16 to 9/21]LD3 Ver. [10/21 to Present] DES Series (All MBH) DES Ver. [05/00 to 06/03]DES Ver. [06/03 to 04/05]DES Ver. [05/05 to 06/07]DES3 Ver. [05/06 to 06/09]DES3 Ver. [07/09 to 09/12]DES3 Ver. [10/12 to 08/14]DES3 Ver. [08/14 to Present] DET Series (All MBH) DET Ver. [06/03 to 04/05]DET Ver. [05/05 to 06/07]DET3 Ver. [08/06 to 06/09]DET3 Ver. [07/09 to 09/12]DET3 Ver. [10/12 to 08/14]DET3 Ver. [08/14 to Present] RH Series (All MBH) RH Ver. [07/01 to 04/05]RH Ver. [05/05 to Present]RHT Ver. [05/05 to Present]