I have had 3 great winters since I(me) installed this unit but today the exhaust fan runs but igniter never clicks plus no main blower. I bypassed the thermostat, that's not it.the troubleshooting charts are too veige for this DIYer.I don't want to replace an ignition controller if I don't have to. I have used detailed flow charts that worked great. I can't find them fot this. Any help or suggestions are greatly appreciated!

Rick

Are you getting an error code on the board? If so, can you let me know what it says. Sounds like the pressure switch isn't closing. This could be as simple as a plugged pressure switch hose, or the port on the draft inducer where the hose hooks to. If that all checks out, take the vent off the draft inducer and visually look to see if maybe a bird or something got in there, also take the cap off outside and look in there. A plugged vent will cause the pressure switch not to close. Do these things then let me know if it worked, and we will take the next step. Good luck.

Wow! Thank you for reply.
Well I misread the symptoms. The unit is 10 feet high I got on a ladder and I can see that the burner lights when the exhaust fan comes on but after 45 seconds the blower should kick on, instead it just shuts down and one minute later it starts over again. After about three or four times it just keeps running the exhaust fan only with no burner and no shutting down, I have to kill power to stop the exhaust fan. It is a pdp75ae0130 made in 2005.
Much thanks!

Okay. Sounds like you may have a bad blower motor. Check to see if you are getting power to the motor when it should be kicking on. If so, and the blower isn't turning, try giving it a little manual push with a screwdriver. If it takes off, you may only need a new capacitor(if your motor has one). If no cap, and the motor is getting 120v, then you will need a new motor. What is happening, is the high limit is tripping because the unit is getting to hot from the blower not kicking on. After it shuts down, and cools off for a minute or so, the limit resets itself and the process starts over. Usually after it trips three times in a row, it will go into lockout mode for an hour or so before trying again, unless you kill power to the unit, that will reset the board.

So, check for voltage to the motor, and let me know what you find. Good luck.

Hi again and again thanks!
I'm familiar with starting capacitors and tried that first.

Today I put 110v to the motor leads and motor is perfect.

The Pressure switch is good too. I tested by pinching the hose and disconnecting a lead on the micro switch. Both killed the flame instantly. Nice.

The limit sensor switch mounted to the side wall seems to be a n/c switch and tested zero ohms when the unit shuts down. Then shorted manually and nothing changed.

The ignition controller is only for the gas system.

It has to be the TIME DELAY RELAY!! Yeah!!

What else is there?

Rickit

Yep, if you have a separate time delay control for the blower, sounds like a new one should have you up and running. Let me know.

Thank you.
It should be here tomorrow. Just in time for colder weather. The good thing to come of this is that now I know what every part of the heater is and does. This makes it easier to repair in the future. No more mystery.

Rickit

That's right. Its always nice to learn about these things. When it really comes down to it, there really isn't a whole lot to them, just. Kind of overbearing if you don't deal with them a whole lot. Glad you took the time, and had the basic knowledge to figure this out on your own. Good job.

The part arrived and now all is good with the Heater. Thanks for your help!

Rick