I replaced the exhaust blower today after the old one was running rough. It runs smooth and quiet now. Problem now is that igniter glow coil will not ignite. Switched it out with a new one because they usually go bad after a couple of years. Still no ignition. I checks connections and grounding. Checked for blockage in exhaust pipe, found none. Should be pretty simple. Any helpful thoughts would be gratefully appreciated.

There is a pressure switch on the direct vent system. You will see a box roughly 4" X 6" with two low-voltage leads going to it (make sure with a volt meter that they are in fact low-voltage).

There will be a tube going to the pressure switch from the pipe. If you unscrew the connection to the pressure switch you can blow into it and you should hear a click (making the connection). Check for blockage. You can also put a jumper wire on it, across the two terminals and the unit should fire. If it does you either have blockage or the pressure switch is bad.

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Originally Posted by dewey066

There is a pressure switch on the direct vent system. You will see a box roughly 4" X 6" with two low-voltage leads going to it (make sure with a volt meter that they are in fact low-voltage).

There will be a tube going to the pressure switch from the pipe. If you unscrew the connection to the pressure switch you can blow into it and you should hear a click (making the connection). Check for blockage. You can also put a jumper wire on it, across the two terminals and the unit should fire. If it does you either have blockage or the pressure switch is bad.

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Thank you so much for your helpful advise. As I did jumper the two wires it did fire up and works fine. Now all I have to do is get the new switch. I don't believe there was any blockage for I could here the flap as I blew into the tube. Thanks again for saving me a lot of time guessing.

How old is your furnace? On the older units they had two ports that looked the same that the pressure switch hose hooked to. One in front, and one in back. You need to hook to the one in back, as the one in front is not pre-drilled. Lots of options to your problem so exact model and serial numbers of the unit would be of great importance to any tech. Or, pics would be of great assistance also.

Quote:

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Originally Posted by dewey066

There is a pressure switch on the direct vent system. You will see a box roughly 4" X 6" with two low-voltage leads going to it (make sure with a volt meter that they are in fact low-voltage).

There will be a tube going to the pressure switch from the pipe. If you unscrew the connection to the pressure switch you can blow into it and you should hear a click (making the connection). Check for blockage. You can also put a jumper wire on it, across the two terminals and the unit should fire. If it does you either have blockage or the pressure switch is bad.

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Well, I replaced the pressure switch and it still won't fire. I did indeed jumper it and it did fire. Now when you say blow into the tube going to the switch it should click. When I blow into the tube... nothing, but if I suck it pulls the pressure switch closed and it will fire. What type of blockage could there be or am I looking in the wrong spot. The pressure switch I replaced the old with was the recommended replacement part. A little befuddled. �� Any more thoughts? Thanks.

Okay, sounds like you now either have a draft inducer problem, or a blocked exhaust vent. Possibly even a blocked port on the draft inducer where the pressure switch hose hooks to the draft inducer. Check the hose port on the draft inducer assembly, is it clear? If so, unhook the vent directly off the furnace and see if things work correctly. If so, check the entire vent run for blockage. Could be a weak draft inducer. Could be a bird in the vent system. Could be a lot of things. It may require the tools and expertise of an on sight tech to check things out correctly. No matter what, don't use the system with the pressure switch jumped. The pressure switch is a very important safety component of the system. If it is bypassed other than for trouble shooting, it can lead to a very serious safety (life threatening) issues.

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Originally Posted by mygirlsdad77

Okay, sounds like you now either have a draft inducer problem, or a blocked exhaust vent. Possibly even a blocked port on the draft inducer where the pressure switch hose hooks to the draft inducer. Check the hose port on the draft inducer assembly,,is it clear? If so, unhook the vent directly off the furnace and see if things work correctly. If so, check the entire vent run for blockage. Could be a weak draft inducer. Could be a bird in the vent system. Could be alot of things. It may require the tools and expertise of an on sight tech to check things out correctly. No matter what, dont use the system with the pressure switch jumped. The pressure switch is a very important safety component of the system. If it is bypassed other than for trouble shooting, it can lead to a very serious safety (life threatening) issues.

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The vent pipe on the outside has a mesh on it that has been there for years. I have checked the exhaust while the blower was running and it blows out like, a hand dryer in a bathroom... with authority. There is no way a bird or anything could get in the pipe. Thank you for your thoughts on this.

Okay, time for an onsite tech. A good tech should be able to get this figured out in short order once he/she gets test equipment and hands on it. Good luck and please let us know how things work out.