lennox package unit

[anthonyac1]

im throwing this one out there. hoping someone came across this issue, it has gas heat, with electric backup rtu. maybe 5 -7.5 tons. i was checking all the ac's at this new account (restaurant), came across this one that was off. the circuit board was about 6"x12" it gave a fault code of #4 which meant smoke alarm fault. in the unit it had a pan relay from the pannel com. and N.O. jumped it out reset the unit thinking the contacts in the switch were bad. same code. but once i take off the r wire going down to the tstat or a wire that is in the r circuit such as 1 wire off the smoke relay unit fires up and runs smooth.cools down to 72. so i was confused the book said if the unit cannot locate a thermostat it will run off the supply and return air sensors. i looked down the return duct and see a duct detector ima go back monday and try to reset it. but if its that it shouldnt run at all. it started pouring and i didnt get any info please don't ring my neck. but its something that failed or stuck open because as soon as i reset it the born lights up then flashes the code. it doesn't even start. im hoping someone by luck ran into the same issue.

[Texas-Tech]

I personally have never seen a gas pack with ele backup heat. What is that all about?

[timebuilder]

Code 4 can also mean a problem at the fire control panel, because that panel can affect the detectors.

Reset all detectors, and if the problem persists, you may have a loose wire at the SD terminals or a bad supervisory relay, which means replacing the detector.

I'd do the reset, and if that fails, determine which detector is in trouble, and see if it is something simple. If applying a jumper at the detector clears the fault, you will probably need a new detector. Get the info off the detector an install the same thing. I like to photograph the wiring before I begin.

[anthonyac1]

I personally have never seen a gas pack with ele backup heat. What is that all about?

haha thats a dumb one on my part. i must admitt there is no way of backing out of that one.

[anthonyac1]

Code 4 can also mean a problem at the fire control panel, because that panel can affect the detectors.

Reset all detectors, and if the problem persists, you may have a loose wire at the SD terminals or a bad supervisory relay, which means replacing the detector.

I'd do the reset, and if that fails, determine which detector is in trouble, and see if it is something simple. If applying a jumper at the detector clears the fault, you will probably need a new detector. Get the info off the detector an install the same thing. I like to photograph the wiring before I begin.

im going to check the detector on monday because they were busy in that area n wouldnt allow me to set up on the floor with a ladder and all that good stuff, i appreciate your response

[Bklyntek]

Hi guys, bklyntek, yes an SD is wired to a N.O. Contact, this way panel will interrupt control power if activated. You may have an S.D. in both supply and return ductwork. But beware it can be somewhere else in the fire control loop.

[timebuilder]

Story time!!

I get a call to go to a store down on Delaware Ave in Phiily. A major office supply retailer named after a paper fastener. They have no AC.

I go up on the roof, and every Lennox L series unit has a code 4. WTF (why the face?) I say to myself.

Nothing wrong in the units. I decide to go look at the fire panel.

Me: "Say, can you tell me where the fire panel is located?"

Ms. Manager: "gee, I don't know."

I notice the wires go down a wall in a conduit, and don't seem to terminate in the store. Hmm.

I go next door, to a vacant space where construction is underway. Lots of demo activity. I find an electrician. I say "hey, was there a fire control panel on that board over there, the one with all the wires hanging out?"

"Yeah, I removed it this morning. Gotta make room for the new panel."

Me: "ahhh...."

So, I get on the phone to the real estate management Co. He is happy I told him about it. They sent a guy from the alarm Co out the next day to install new panel.



IN THE STORE!!!!!