I just installed Heliocol solar panels. Although I can hear/feel the solar on in the pipes beyond the valve (in addition to seeing my iAqualink tell me it's on and seeing to control valve turned on), but it's not heating enough. My pump is a fairly new 2-speed:
Jandy Zodiac FloPro FHPM 2.0-2.
I had replaced the impeller with a 0.75 HP impeller to try to get better energy efficiency. However now that the solar doesn't seem to be working right, I think I am probably not getting optimal flow to the solar panels. I asked the installer if it seemed the flow was OK, since I read here by feeling the panels you can tell if they're getting to hot and not absorbing heat due to too slow flow rate. Anyway, I don't think my installers evaluated that aspect. Anyway, the installer's suggestion was for me to switch the impeller back to 2.0 HP.
So while doing so, I decided to see what kind of energy savings I was getting with the smaller impeller. Results with clamp amp meter: 240 volts. Amps:
0.75 HP impeller: 3.0 in low-speed, 5.25 in high-speed
2.0 HP impeller: 3.2 in low-speed, 8.8 in high-speed
Seems like less savings than I would expect if I swapped a 2.0 HP pump for a 0.75 HP one. Especially less than 10% difference in low-speed.
My first thought before measuring was that if it worked with the original impeller I should try replacing it w/ a 1.0 HP impeller. However maybe I'm not getting the efficiencies of lower HP by just replacing the impellers.
So my questions are:
1. Does this seem unusual?
2. If going back to the original impeller fixes the problem, should I consider getting a variable speed pump, or replacing my pump with a 1.5 or 1.0 HP 2-speed pump?