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Lennox SL280UHV series gas furnace- intermittently works

8146 Views 17 Replies 7 Participants Last post by  supers05
Hi, I am renting a house that has a 3 year (ish) old Lennox SL280UHV gas furnace that sometimes works and sometimes doesn't. I am the third renter so I have no idea if any maintenance has been done on it (and I highly doubt it has). My landlord/property manager creeps me out and I'm a single woman so I"m hoping someone can help me. Is there something simple I can try to do before calling this guy? OH yeah....he lives across the street so I can't just call in a company and pay for them to service the furnace. :vs_no_no_no:

Honeywell thermostat is working fine and wires are secure.
Furnace tries to light 3 times in the morning (I can hear it in crawl space) and then won't go on. The interesting thing is that sometimes I can get it to start by turning off the circuit breaker, wait about 10 minutes or so, and then flick it back on and the furnace starts up. But sometimes it won't.

OR it's not working in the morning and then I come home from work and then it is. Any ideas that I can easily try? I'm pretty handy but don't have tools such as a voltage meter or such.
I live in Colorado. Thanks in advance! It's supposed to snow this weekend so a quick answer(s) is GREATLY appreciated!
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Without his blessing you will be resposible if anything you do causes any damaged. Just remember that.

It is his resposibility to ensure his renters are taken care of. You have a very ligimate complaint. I would call him.

Please wait for the hvac techs to respond. They may have more advice. Thanks.

Hope you get it working right soon.
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Look at teh error code, and see what it is saying. May just nee its flame sensor cleaned. or could be moisture in the pressure switch hose..
How can I find these items?
Understood....however, I'd rather not have a creepy guy in my home if I can....hence the asking of simple troubleshooting advice :)
It could be the flame sensor needing cleaning but it is a very low 34" furnace and not easy to get at the sensor. Get your Brother or a male friend or relative to be there and get the landlord to fix it.
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well really alot of top notch techs ...are creppy..but there only intrested in their work....you know geeks...:biggrin2:
Troubleshooting will require you to go into the crawl space. A meter may be required, along with working with live electricity and gas.
I'm concerned about the property manager....not HVAC techs.
I'm concerned about the property manager....not HVAC techs.
thougth you ment the property manager would work on furnace...sorry...but it still is funny:wink2: then i would agree with yuri ..have somone there with you...
Get a pitbull. That ought to keep him away.:smile:
Please...this is serious. Thanks for the replies...but for all those wanting to reply, please keep it to the helpful suggestions on what I can try as my troubleshooting proceedures. Thanks!
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Most likely the flame sensor is dirty as the basement is probably damp or dirty and they need cleaning anyway. If you remove the front door it sticks in front of one of the burners and looks like one of these. Has a wire going to it and has a white procelain holder. Remove it and clean it with new clean steel wool or #800 emory paper.

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as mentioned..need to look at error code in furnace window..that means going into the crawl space..sounds like flame sensor may need cleaned,may also have a clogged trap setting of the pressure switch,


if the model number is correct that is an 80% furnace''
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I'll double check the model number but I thought it was the SL280UHV (series). ?
I'll double check the model number but I thought it was the SL280UHV (series). ?
if it is an 80 % model it won't have a trap...but it could have a clog on the pressure switch tubing or a small clog at the port on the inducer wher the tubing connects too..
Please...this is serious. Thanks for the replies...but for all those wanting to reply, please keep it to the helpful suggestions on what I can try as my troubleshooting proceedures. Thanks!
Don't worry, those not quite on topic suggestions are half from boredom and half from legitimate concern.

Back on topic, been asked if you can read the error code on the furnace. You'll have to actually be at the furnace, even if that means crawling through a crawl space. (I hope that it's easier done then said) You'll have to remove the front cover. iIRC, there's no screws holding it. There will be a window in the lower half, and a flashing light behind it. I've copied the flashcode description table for


Straight from that manual:
The SureLight® integrated control features a red LED light, for furnace status and troubleshooting. The LED flashes in X"+ Y" codes. For example using table 4 under PRESSURE SWITCH CODES", if the red LED flashes 2 times, then off for 2seconds then flashes 3 times, the low pressure switch is failed open. Two green LEDs show indoor blower status and CFM.


FLASH CODE DESCRIPTIONS

Pulse) A 1/4 second flash ON / four seconds of off time.

Heartbeat) 1/2 second bright / 1/2 second dim cycles.

X + Y) LED flashes X times at 1/2 second / two seconds off / flashes Y times at 1/2 second / four seconds off −repeats.

Pulse) Control powered (standby) Also signaled during cooling and continuous fan.

Heartbeat) Call for heat − normal operation

FLAME CODES

1 + 2) Low flame signal −− Check flame sensor.

1 + 3) Flame sensed out of sequence −− flame still present. Flame sensed without gas valve energized.

PRESSURE SWITCH CODES

2 + 3) Low fire pressure switch sensed open. 80% − check blocked exhasut (90% check inlet/exhaust or condensate line. condensate line)

2 + 4) Low fire pressure switch sensed closed prior to activation of combustion air inducer.

2 + 5) High fire pressure switch sensed open. 80% − check blocked exhaust (90% check inlet/exhaust orcondensate line)

2 + 6) High fire pressure switch sensed closed prior to activation of combustion air inducer.

2 + 7) Low fire pressure switch opened during ignition trial or heating demand.

LIMIT CODE

3 + 1) Primary / Secondary limit switch open.

WATCHGUARD CODES

4 + 1) Watchguard −− Burner failed to light, exceeded maximum retries. (auto retry after 60 min)

4 + 2) Watchguard −− Low pressure switch opened 5 times in one heating cycle. (auto retry after 60 min.)

4 + 3) Watchguard −− Lost flame sense 5 times in one heating cycle. (auto retry after 60 min)

4 + 5) Watchguard −− Limit open longer than 3 minutes. (auto retry aftrer 60 min.)

4 + 6) Watchguard −− Flame sensed out of sequence; flame not present. (auto retry after 60 min.)

4 + 7) Watchguard −− Ignitor circuit fault −− failed ignitor or wiring. If ignitor and wiring are okay, replace control.(auto retry after 60 min)

4 + 8) Watchguard −− Line voltage below 90 volts

HARD LOCKOUT CODE

5 + 1) Rollout circuit open −− Reset rollout switch, check wiring and recycle power to furnace.OTHER CODES

5 + 2) Control failed self check, internal error (control will restart if error recovers).

5 + 3) No Earth ground (control will restart if error recovers).

5 + 4) Reversed line voltage polarity (control will restart if the error recovers).

5 + 5) Low 24V (control will restart if voltage rises to normal)

Cheers!
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