My next door neighbour has a concrete inground pool with a spa pool attached to it. I also have an inground fibreglass pool and have always attempted to resolve my own pool problems.
This morning he called over and asked for my input to what might be the problem with his spa. I'll try to include as much information as possible. The spa measure approx. 2 metres x 1.5 and is about 2 metres deep with steps.
The spa is salt water chlorinated and solar and gas heated. It has 6 jets that are controlled by the main pump which is a Hurlcon CX320 (240V 1630 Watts). Pump seems fine, working as it should. No visible leaks, no unusual noise and visually the filter is spotless. 2 jets at the side are for the heating.
Only 3 of the spa jets are working (and two of them have less pressure than one of them). With the other 3: one is delivering a very low pressure stream of water (almost not visible) and the other two are sucking? rather than "blowing" water. If you block the jet adjacent to the one that is discharging at very low pressure - the stream pressure increases marginally.
Any ideas where to start trying to analyse what is going on here. My first thought was the possibility of a partially blocked inlet (there appears to be 6 inlets?) from the spa to the pump, but not sure how you would check that.