I have my Aqualink controlling my Hayward heater right now via a 2 wire "fireman" connection. The Hayward is in "remote/BO" mode with SPA selected and the spa set temp a few degrees higher than what I would ever want. The Aqualink controls the temperature via it's inline probe, and cycles the heater as needed, meaning the Hayward never reaches it's set temperature. This all works as intended.
However...
I'm finding the stability of the temperature in the hot tub to be pretty shaky, especially in the 20 minutes or so after it's come to temperature. The Aqualink temp probe is 6 to 7 degrees warmer than the hot tub, though this variance gets better the longer things run. I've bumped the filter RPM up to 3500 from 2800 and that seems to make things a big better. I've maxed out the temperature compensation Aqualink allows (4 degrees, I believe). I don't know if there's a way to decrease the amount of time the Aqualink takes between cycles (I think it's 5 minutes by default?), but that might fix the issue, if it didn't hurt the equipment somehow. Does anyone know if this is possible/advisable?
I've thought about going to 3wire mode by moving the non-common AQUALINK heater wire from HAYWARD SPA terminal over to HAYWARD POOL terminal, and then wiring an spare AUX relay to connect the HAYWARD SPA to COMMON. In that way, the Aqualink heater function would still work, albeit via the HAYWARDs Pool set temp, for things like freeze protection. Then if I wanted to use the SPA, I'd have to flip on that AQUALINK AUX instead of turning on the AQUALINK HEATER, though I could probably hide that complexity (and filter RPM) behind a one touch button. In this way, it'd be the HAYWARD spa set temp managing the spa. I'd loose cool down after spa use if I did that, though my old setup never had that anyway. Anybody ever try this type of setup?
However...
I'm finding the stability of the temperature in the hot tub to be pretty shaky, especially in the 20 minutes or so after it's come to temperature. The Aqualink temp probe is 6 to 7 degrees warmer than the hot tub, though this variance gets better the longer things run. I've bumped the filter RPM up to 3500 from 2800 and that seems to make things a big better. I've maxed out the temperature compensation Aqualink allows (4 degrees, I believe). I don't know if there's a way to decrease the amount of time the Aqualink takes between cycles (I think it's 5 minutes by default?), but that might fix the issue, if it didn't hurt the equipment somehow. Does anyone know if this is possible/advisable?
I've thought about going to 3wire mode by moving the non-common AQUALINK heater wire from HAYWARD SPA terminal over to HAYWARD POOL terminal, and then wiring an spare AUX relay to connect the HAYWARD SPA to COMMON. In that way, the Aqualink heater function would still work, albeit via the HAYWARDs Pool set temp, for things like freeze protection. Then if I wanted to use the SPA, I'd have to flip on that AQUALINK AUX instead of turning on the AQUALINK HEATER, though I could probably hide that complexity (and filter RPM) behind a one touch button. In this way, it'd be the HAYWARD spa set temp managing the spa. I'd loose cool down after spa use if I did that, though my old setup never had that anyway. Anybody ever try this type of setup?
