Got a 200,000 BTU that won't light. Replaced the rocker switch and igniter. Igniter glows and I can see the fuel going past the igniter, but it won't fire up.

Hello, Most newer gas furnaces (propane or natural gas) has one of several different types of igniters. The most common one is called a hot surface igniter. This is a ceramic easy to break, glow coil, glowing igniter. Some has a Spark igniter that lights all the burners from a constant spark and some light the burners off a pilot proven /spark igniter. This one sparks then lights a pilot then the burners will come on. In any case if any of these types are not working they could be cracked or broke. Also the inducer draft motor has to be running, the little motor that hooks to the exhaust of the furnace ( if it has one ). This causes the pressure switch to close then the igniter should come on. My suggestion is to call a qualified service tech from your area to assist you. To determine which one of these may be your problem they will have to perform several test. Hope you get going soon. I hope this helped. J

Remove the top and turn the heater on. Look for the igniter and make sure it is working. I don't know which type you have, but it could be the spark plug type or may be a HSI (hot surface igniter which will just glow until the heater starts). If the igniter isn't working, you may need to clean the sparkplug and set the gap. You can also check the transformer for the igniter. If it is the HSI type make sure it isn't broken off. Also check the flame sensor.

Well it is getting fuel but is it atomized in very small droplet form? If so is your igniter close enough to ignite the fuel? You see these spray a very fine conical mist under high pressure, if the mist is not defined or conical it sprays past the igniter. If it is fine and cone shaped it could be the positioning of your igniter. Please check both by removing the top section of the heater and watch what is going on in there. My thoughts are a bad nozzle and if you replace it pay attention to spray angle and GPH rating printed on the side of the nozzle.

If you are firing, and then going off and getting an E05, your igniter is to blame. It may be glowing but it's getting weak. The diagnostic goes further but that is usually the fix.. With inactivity, the igniter is always to blame. You really need to fire it off weekly to make it reliable and make sure that your heater is serviced at least one time a year to keep all the internal components operating as designed.

• PILOT ASSY LP MV CH150 IID
• Manufacturer: PENTAIR WATER POOL AND SPA INC
• Manufacturer Part #: 471291
• Description: Propane pilot assembly for heaters with millivolt ignition.
• Retail Cost: Approximately $65.00

Try consulting the owners manual for these pool heaters. The troubleshooting guide is very thorough. However, it it wont fire at all and the service light comes on, you are probably going to need to replace at best case your ignition, and at worst case, your entire pool heater.

http://www.backyardcitypools.com/images/bwp/Max-E-Therm-Manual.pdf

Hi see if the ignitor is glowing , or has a crack in it jump out pressure switch see if it glows then , possable new ignitor

sounds like an ignition problem. The fan is supposed to start first to get the airflow going, then the igniter should heat up (glow igniters) or start sparking (spark plug igniters), then the fuel starts pumping. If the igniter is not working the fuel won't start. Things to check.... igniter - see if it is intact, fuse (usually in the circuit board), If those are ok, then check fuel pump, fuel filter, air filter. Hope this helps.

The way it works is the igniter gets voltage signal from the control and will start to glow. The gas valve for the burner and the igniter are wired on the same circuit. When the igniter starts to glow it takes all the voltage from the circuit. As the igniter increases in temp the resistence changes and the voltage starts to travel to the gas valve. Once the gas valve registers 3 to 4 volts it will open allowing gas to the burner for ignition. The igniter needs to reach approx 2200 degrees for this to happen. So it could be the igniter or the gas valve. The igniter should test approx 500 to 700 ohms with a ohm meter. The gas valve could also be sticking. If the igniter is glowing bright and you tap the gas valve with a wrench and it comes on then the gas valve is sticking and needs replacement(as long as the igniter tests good)...Hope that helps.

CAD flame sensor is bad, also check your air inlet line for the fuel mix, could be cracked.