I bought and installed the above heater this July. It was installed by a licensed gas technician and inspected by MB Hydro. It will intermittently have issues where it will shut off and the temp gauge will spike up and then go back down and then the heater will come back on. no service lights come on, just the orange light blinking when it calls for heat and then the orange light will stay on and the heater will light – you can hear it and you can feel the exhaust and the water is warm….30 seconds later it will shut off even though the set temp is 85 and the current temp is 80. It will keep cycling like this indefinitely and then all of a sudden we will notice it working as expected and have no issue for a few days and then it will repeat. I have a variable speed pump and I have tried a bunch of different speeds ranging from 1000 rpm to 3450 and it happens at all speeds. I have also tried back washing in between and it will still have the issue. This has happened since we first installed it. I have talked to both Sean and John about the issue. I also have a video of the heater having the issue.