What kw Heat Pump do I need for my spa? Sherralyn June 22, 2018 06:05 Updated Follow As a general rule, the 5.5kw Spa Heat Pump works well on spas up to 3000 Liters and 8kw works well on spas/swim spas up to 5000 Liters. For assistance, please contact our support team via our online chat function. Related articles Do I have a venturi or a diverter? Are your heaters easy to install? Comments 0 comments Article is closed for comments.