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Hey I am working on a Goodman GPG10300701A gas pack. This started as a no heat call, when I got to customer site the limit switch in the blower was open. Went to replace it and found the wires off. I put the wires back on the switch and restarted the unit and everything worked great. Cleaned the unit for the customer and tested everything. The next morning I get a call - not working. So I go back to site and the unit is locked out. I reset the breaker and the bottom burner was not working. I test the Outlet pressure it is 8.5 I adjust it back down to 3.5 and the bottom burner comes on and runs. (I could do it the day before because my manometer broke.) So I did a combustion test just to make sure all was ok and it was. Tell the customer no charge head on my way. The next morning I get the same call. Get to unit - it is locked out again! I have checked the fan, filters, gas valve,limit switches, and roll out. I cant tell if it is a time thing or as air temp thing. When I get there and reset the unit, it worked great but it is 65 degrees outside. When it shuts off on the customer it is 40 or so and always at night.
Any clues

Thanks for the help.
 

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how old is this unit and how long did this thing run on 8.5" of gas pressure?
Did you check the pressure switch and pressure switch hose for water?
Direct spark, or hot surface, or intermittent pilot.
were the limit switch wires that were unhooked jumped or was the unit running with the wires unhhoked and not connected.
Why did the bottom burner not lighting make you think gas pressure instead of just dirty burner?
Scooter
 

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First off you might want to make sure that it wasn't LP because that is normal pressure for propane. I went to a call with that same scenario was happening where it wouldn't work at night time. Found the heat exchanger clogged full of soot because it didn't have a LP Conversion kit.
 

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When you've been there how long have you allowed the unit to run? If you're walking away from it without letting it run as long as it could conceivably need to run at night when it's colder, then the problem is most likely present at all times, not just at night.

The thing fails 3-5 times throughout the day \ evening and locks itself out by night time.

Amp out the blower motor...maybe it is going out on thermal overload after sustained run time, causing hi-limit. Otherwise your heat exchanger may be suspect (not sure how old this unit is...but it wouldn't be a surprise if it was a natural gas unit running at 8.5" WC for any considerable period of time)

Somebody jumped out the hi-limit for a reason (scary tactic though)

-Jason
SUREFIRE Mechanical- Long Island Air Conditioning Repair Experts
 

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Its probably due to excess water in the combustion gas due to inlet air temp causing more condensate at lower ambient temps. do you have a code from the unit? whats the lock out code? im wondering if the condensate is heavier at night and the flue isin't piped correctly or if hoses are not in the right places it may back up into the draft inducer housing and mess up the pressure switches. first things first, whats the led flash code?
 

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Hey I am working on a Goodman GPG10300701A gas pack. This started as a no heat call, when I got to customer site the limit switch in the blower was open. Went to replace it and found the wires off. I put the wires back on the switch and restarted the unit and everything worked great. Cleaned the unit for the customer and tested everything. The next morning I get a call - not working. So I go back to site and the unit is locked out. I reset the breaker and the bottom burner was not working. I test the Outlet pressure it is 8.5 I adjust it back down to 3.5 and the bottom burner comes on and runs. (I could do it the day before because my manometer broke.) So I did a combustion test just to make sure all was ok and it was. Tell the customer no charge head on my way. The next morning I get the same call. Get to unit - it is locked out again! I have checked the fan, filters, gas valve,limit switches, and roll out. I cant tell if it is a time thing or as air temp thing. When I get there and reset the unit, it worked great but it is 65 degrees outside. When it shuts off on the customer it is 40 or so and always at night.
Any clues

Thanks for the help.
Cracked heat exchanger? whistle noises at all? rollout? whats the temp difference across exchanger?
 

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Its probably due to excess water in the combustion gas due to inlet air temp causing more patio coverscondensate at lower ambient temps. do you have a code from the unit? whats the lock out code? im wondering if the condensate is heavier at night and the flue isin't piped correctly or if hoses are not in the right places it may back up into the draft inducer housing and mess up the pressure switches. first things first, whats the led flash code?
The flash code may reveal the issue... but it's more or less something regarding the temp gauge.
 

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Goodman GPG10 specs

Here is a service manual for the model he gave depending on the year it should work unless the unit is really very old.

http://johnstonesupply9.com/TechDoc...lectric/APG10 Pkg Gas Ele/APG10 Tech Info.pdf

Packaged gas heat and air units are really susceptible to corroding at the burner head where the tubes light the gas down the row of burners, also I have seen where the tubes for the inducer mount to the metal connection just corroded shut and also spiders making nests blocking off ports as well let alone the other problems of really not knowing what was going on with the actual fuel gas type and limit sensor wires.

This is just for the people who's heads are still trying to figure out the problem but I don't think there was very good info given in order to go on. Maybe next time
 
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