H400 natural gas heater that was throwing the IF code
I have an 18 month old H400 natural gas heater that was throwing the IF, ignition failure error code when we started the pool last week.
The local "pro" from a large installation and maintenence company that pulls the cover for us and gets the filter up and running told us that the keypad, the controller board and the motherboard needed to be replaced. All for the low price of $650. These things are very complex he explained.
Not being one to cough up that much dough without a fight I decided to take a look at it.
From the Hayward wiring diagram, It could be one of 4 things: igniter, flame sensor, low gas pressure or the control board
Time for some basic troubleshooting:
1. Is the heater behaving as it is described in the Hayward manual before displaying the IF? Yes it ran though 3 cycles 30 seconds apart before displaying the IF. The blower was operating and I could briefly smell gas as the blower cleared it out between cycles.
2. Is the igniter working? After running through one cycle and displaying the IF, I opened the circuit breaker and removed the igniter; it was still very hot to the touch. I reinstalled it.
Removing the top cover form the H400 to clean out leaves & small twigs that had accumulated I could see the heater core. I closed the circuit breaker to watch the ignition sequence through the heater core BEING CAREFUL NOT TO PUT MY FACE DIRECTLY OVER THE OPEN COVER, I could see the igniter glowing cherry red as it went through the 3 cycles. Yes the igniter was working but I could not see any open flames.
3. Is the flame sensor working? With the breaker open, I removed the flame sensor cleaned up some built up scale by gently using some 600 grit sandpaper. Checked the connection at the controller board, it looked good. At this point I was not sure if the flame sensor was working. I reinstalled it.
4. Is there enough gas pressure? I could get a whiff of gas during the ignition sequence but I had no idea if the pressure was correct or if the orifices were obstructed. I turned off the power and the main gas valve outside the unit. Disconnecting the gas pipe I removed the 4 screws that hold the orifice manifold in place. It came out easily.
Upon inspection, the orifice that is adjacent to the igniter was blocked with a spider web. See the attached pics. The orifice on the left is clear and the one on the right is blocked. I removed the orifice with a 7/16 wrench and cleaned it out with a bamboo skewer.
I reassembled everything, turned the gas on and checked all the joints for leaks with soapy water. Once I was satisfied that there were no gas leaks I closed the circuit breaker and the unit fired right up.
If you are not comfortable with working on gas lines get a plumber or a competent pool tech that you trust to check the gas orifices.
