Low flow vertical hot tub spa heaters will usually be mounted vertically like a juice can on the side of the control box. Some heaters have replaceable elements but most don't.
Savannah Spas heater assembly for hot tub spas - $170.00
Savannah Spas
26-00257
Vertical heater assembly
3" x 10.10" housing
4.0kW/240v
1" 90° socket tail piece
Part # Description
46-371-1300 Low flow assembly, 4.0kW/240v More Info
Sunbelt Spa heater assembly for hot tub spas - $218.59
Sunbelt Spa
26-08147
Vertical heater assembly
3" x 6.469" housing
5.5kW/240v
1" 90° socket tail piece
10/3 SO 36" cord w/terminals
Part # Description
46-371-1315 Low flow a... More Info
Sundance Low Flow heater for hot tub spas - $519.65
Sundance Spas
Vertical heater assembly for sundance spas and hot tubs
3-1/2" x 13" with 3/4" barb x 3/4" 90°
barb inlet/outlets.
Rated at 5.5kW/240v.
Purchase of a foam
wrap... More Info