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 Are your heaters easy to install? What is the difference between the SpaNet Hybrid & Power Save Heat Pump? Comments 0 comments Article is closed for comments.