Heaters have a pressure switch... In my mind the best method is to turn the pump to the lowest RPM you plan to use and see if the heater works.. If not, keep increasing the speed about a 100 RPM at a time until the heater's pressure switch closes.. Then add a 100 or so RPMs and call that your "heater speed."
Is this a standalone pump/ or do you have automation? Does your pool has a saltwater chlorine generator (SWCG)??
The heater should be starting and stopping, unless the heater hits the temperature you set for it.. If you have enough RPMs to turn it on, it should be turning off..
New pump is in and working beautifully. Unfortunately I have a “SW Rollout Switch Open”. Which I suspect happened before the install. The old pump was not working correctly and flow was slow and the old pump was so hot that you could not touch it. Do you think this could cause the switch trip? My burners are clean. See picture. Let me know what you think. I have a new thermo switch, have not installed it yet.J,
Have you actually tried to run the heater yet? I am not sure about the "too low of an RPM theory", but if you find the heater is cycling, just adjust the RPMs up.
The IntelliFlo is a great pump by the way...
I have the older version 011018.. I don't have a heater and run mine most of the time at about 1200 RPM.. I suspect with a heater you will need to run at 1500 or more.. But that is just a guess as each pool's plumbing is different, that is why you need to experiment to see what works best for you..
I would not run less than a 1000 RPM as you really don't save much at that speed.