Pentair e5 error code

SOURCE: Pool heater will not heat

Im no pro, but I know there is an air sensor behind the main board. If the fan is running you probably have a problem with that sensor. If your lucky the air hose could have just popped off.

SOURCE: My pool heater will not start. The power light is off and the pressure sw is lit.

You must turn on the pump and let water circulate through the pool and the heater before you turn on the heater otherwise you will ruin the heater

SOURCE: R=5 CODE ON A PENTAIR HEATER ?

flame sensor falure, probally your pilot.

SOURCE: E04 comes on after fan purge cycle-Pentair minimax nt pool heater

This is a fan falure code. It can mean the fan has problems (not likley if the fan goes and isn't labored) You have a sensor in your exaust (probally not this if you don't get a good start) The culperet is probally in the negetive pressure sensor. This is a 2-3 inch disc with wires going to the controls and a rubber tube going to the fan. Pull the tube from the fan and make sure the fan fitting is clear (poke with a tooth pic) Be sure their are no kinks in the hose. If the heater is 4 years old the diaprahm could be bad in the pressure sensor. Check the other things first but this is probally your problem. Good luck, hope this helped.

SOURCE: I have a Pentair Mastertemp 250 pool heater with

This is an ignition flame falure code. Could be you don't have gas getting to the pilot, no spark to ignite the pilot or your ignition is not reading the flame. Sorry to say but it's probally time to get the pool guy out to look at it. Good luck.