I had a potential customer call me today to look at their pool, complaining that they had DE in the bottom of the pool and requesting a quote for weekly maintenance. Of course once I got there, the pool was full of algae and you couldn't even the bottom
Anyway, the first issue I noticed was that the filter pump had lost prime. After shutting it off, I took the top off of the pump basket and what water remained in the pump was actually steaming I re-primed the pump and everything seemed to be okay...apparently good flow. However, that doesn't seem to be the case.
The pump looks like it is going all gang busters, but there is an imperceptible return flow to the pool and the filter pressure gauge is showing 0 PSI. I have not seen this before, because usually heavily soiled, poorly maintained filters show a very high PSI. At first, I suspected a bad gauge on this 6 year old filter, but the lack of a return flow to the pool makes me second guess this. This model of filter also has an automatic air relief valve that could also be malfunctioning because of its age. Also, the valves are in their proper positions for a good return flow.
I suspect the gauge is not working properly. Any other ideas?