Make sure the condensate drain is not clogged, take it apart, shopvac it
Hey guys,
I went to a call yesterday, and all signs pointed to the vent pressure switch being a failed component. I replaced it, and low and behold still no flame. I put the original back on b/c it has a visible relay, and I can see it move slightly, but not enough to close the contacts. I have checked the inducer, it is drawing .7A @ 120vac, which is what it is spec'd at. I have replaced the tubing from the inducer to the switch, and am finally throwing up the white flag for now... I work on 95% heat pumps and barely see anything else... This week I ran across my first boiler, and now a gas furnace that has got me flustered...... Any help is appreciated, as I don't know where to go from here. ---Thanks
Make sure the condensate drain is not clogged, take it apart, shopvac it
@ Gary... I tried the best I could, but I could not get all up in the 'canister' that the 2 hoses are attached to. Also, there was some gunk built up at where the hose attaches to one side. It tee's into the condensate line for the evap. coil as well... should I run water through it to ensure it is not clegged there as well? Please excuse my limited knowledge of these furnaces, as I mentioned I do not run across them much....
The hoses come off with quickclips (slide them to the side to disengage the teeth of the clip) and then i always unscrew the 2 screws holding it to the case, remove the trap, and clean with water and shopvac. You should have 2 pressure switches, hi and a low. If the drain, or furnace trap are backed up you will get the problem you have. (you may have to cut your lines apart to get to the trap) I then take the trap to a faucet and run water through it.
What sorta neg" w.c. are you getting vs what it is rated for?
Sent from my van
Gotcha.... Thanks Gary. I will check it out in the AM. It is a dual fuel setup, so I got their Heat Pump working, and got my butt handed to me by the furnace so I left to check in here and try to get some help. Ruud was of 0 help. They told me to call the parts distributer, they told me to call 'Steve', and Steve's voicemail said he was in training today. I will, of course, let you know if this worked for me.
@ Daniel, I didn't bust out the manometer. I will find out in the AM if the problem persists. Where is the rating for the pressure located?
ruud is what i put in, and have had this several times, hopefully thats your issue, as its an easy fix.
That's what I like to hear!!!
What's it doing? What pointed you at the pressure switch?
The inducer fan motor fires up, and runs for about a minute... Then everything shuts down. When I jump around it, everything fires off. Also, Ruud has a diagnostic tree and on board diagnostic tool with LED that blinked twice. Which indicates an open circuit at the pressure switch.
Usually on the switch itself
is the switch faulty or is it doing its job??
you cannot go farther without knowing what the switch is rated for and what the actual pressure it is seeing.
get your manometer out. it is your best friend.
if your pulling more than rated, its the switch, if not, a new switch will not help
my boss thinks its possible to repeal the laws of physics
The switch is just doing its job, probably. Diagnose it like every other induced draft furnace out there, Rheem is the same.
Thanks guys... I do not think it is the switch either. However, my lack of knowledge has me at a standstill. I will hook up the manometer first thing in the AM. I am with Gary and believe this unit just needs some maintenance performed on it. However, I am completely lost so keep throwing ideas out to me and I will keep trying until I make it through this one!
And for the record it is rated @ 1.11" WC
If not already mentioned, secondary heat exchanger could have water in it. Something could be blocking the flue as well.
@408 I feel that the exhaust is sufficient, based on only my hand against the pipe outside. I know that is a rudimentary way to measure it. But, you have my interest with the secondary heat exchanger... Please elaborate, I know nothing of this. Thank you
the secondary is the second pressure switch, and the drain, thats the issue's ive had before and why i think its likely from the drain (clear it, and hopefully thats it) you will be suprised the crap that comes out of that trap, even at only a year old, plus the ac is tied in you said, which is more load on the drain.
Chuck, I really don't know much about gas furnaces.... I do not see them very often. If you can point me in the direction of some good literature, I would be stoked to read it. I am not ignorant on these appliances, just uneducated... I do not run across much other than heat pumps, of which I am quite proficient at working on.
Just because you feel wind blowing don't mean it's not .10 in wc off and not closing, check the ports the ps tubes go to on both ends for junk, and the trap. Tee in to the pressure switch to check pressure