I have Pentair Minimax NT spa heater and the heater won't come on. The inside panel shows one blink of a red light, "air flow fault". The only light I have on the control panel is the Pressure SW light. I have already replaced the transformer, per the Pentair customer service person's recommendation, but to no avail. Any ideas? Thank you.

Welcome to TFP!!

You can check the clear air tubes (like surgical tubing) for water or debris.

Sometimes mice will get inside the blower and make nests down inside. If you're not comfortable removing, checking and reinstalling the blower or ignition module, PLEASE get a heater or pool expert to do it!