Pentair MasterTemp 400 not igniting after changing Fenwal

[barriosj]

Hi everyone. I cant seem to find a 2024 fix for this issue. Here is a bit of what happened to me when i bought my home. First pool and just dont know much but i learn pretty quick from what ive read here. Im just stumped now. Dont know where the issue is now.

Bought the house heater didn't ignite would try 3 times and then service heater light would go on. Replaced the following:

Stack Flue Sensor
Thermistor
Hi Limit Switch
Gas Shutoff switch

Still same problem occurred. No codes on LCD. Read online (this forum) and learned to check FENWAL led light for code. Lit up 3 times. Code was for ignition lockout. Recommended to change igniter/flame sensor.

Replaced:
Igniter and gasket that came with kit.

Same code again (3 blinking flashes) Recommended to change ignition control module.

Replaced:
FENWAL ignition control module
Air flow switch.

Same problem same code. 3 flashes. Ignition lockout.

Gas value is on, no corrosion in box. All breakers on.

All parts from pentair.

 

[1poolman1]

Hi everyone. I cant seem to find a 2024 fix for this issue. Here is a bit of what happened to me when i bought my home. First pool and just dont know much but i learn pretty quick from what ive read here. Im just stumped now. Dont know where the issue is now.

Bought the house heater didn't ignite would try 3 times and then service heater light would go on. Replaced the following:

Stack Flue Sensor
Thermistor
Hi Limit Switch
Gas Shutoff switch

Still same problem occurred. No codes on LCD. Read online (this forum) and learned to check FENWAL led light for code. Lit up 3 times. Code was for ignition lockout. Recommended to change igniter/flame sensor.

Replaced:
Igniter and gasket that came with kit.

Same code again (3 blinking flashes) Recommended to change ignition control module.

Replaced:
FENWAL ignition control module
Air flow switch.

Same problem same code. 3 flashes. Ignition lockout.

Gas value is on, no corrosion in box. All breakers on.

All parts from pentair.

Have you checked for voltage at the ignitor during the start-up sequence? Disconnect the white connector, check at the end connected to the Fenwal. If you have the old ignitor, its easier to cut the the wire off at the ceramic, strip those wire a bit, plug the part into the connector, check voltage at those wires.

 

[ajw22]

Have you checked the gas pressures with a manometer?

So the heater has never worked for you since you owned the house?

You sure all gas valves are open?

What is the CFM of your house gas meter? Post pictures of the data plates.