Ask Experts Questions for FREE Help !
Ask
    dcc0413's Avatar
    dcc0413 Posts: 3, Reputation: 1
    New Member
    		  
    #1

    Nov 22, 2011, 07:26 PM
    Primary limit switch?
    Recently been having issues with my Goodman GMT070-3B, with it lighting and staying lit. I spent last winter lighting it manually. When it reached the thermostat temperature, it cut off and I'd have to start it manually again. I've recently replaced the flame sensor and ignitor. Everything starts up fine now. But the flames go out after approx. 3-5 minutes, and the heater restarts the cycle all over again. I don't know what else to trouble shoot. Any suggestions would be appreciated?
    glass61's Avatar
    glass61 Posts: 11, Reputation: 2
    New Member
    		  
    #2

    Nov 26, 2011, 08:19 AM
    Sounds like a limit switch that would shut the heater off if temp in the heat exchanger gets too high. I would first look at an air flow problem. Filters, flue blocked by bird's nest etc...
    dcc0413's Avatar
    dcc0413 Posts: 3, Reputation: 1
    New Member
    		  
    #3

    Nov 28, 2011, 10:03 AM
    Thanks. I replaced the filter and checked the flue, all clear. Unfortunately I ended up having to spend $106 to have a tech come look at it. I was told that I had a bad heat exchange and that the air pressure switch was shutting the heater off once it sensed the bad heat exchange. YOU WERE DEAD ON! Wish you responded a little earlier. Lol I was advised that I'll need a new heater. So now I'm shopping around for a good heating manufacturer and a honest, trustworthy, knowledeagable, professional installer.
    dcc0413's Avatar
    dcc0413 Posts: 3, Reputation: 1
    New Member
    		  
    #4

    Nov 28, 2011, 10:08 AM
    Thanks. I checked the air pressure switch and couldn't find anything wrong. I also replaced the filter and checked the flue, all clear. I ended up spending $106 to have a tech come out and tell me that I have a bad heat exchanger and the air pressure switch was sensing the bad heat exchange and kept cutting the heater off. YOU WERE DEAD ON! I wish you would've responded a littler earlier. (lol) I was advised that I should just get a new heater. So now I'm shopping around to find a reliable manufacturer and a honest, knowledgeable, and professional installer. Any suggestions on a good heater?
Not your question? Ask your question View similar questions
 

Question Tools Search this Question
Search this Question:

Advanced Search

Add your answer here.


Check out some similar questions!

Have a limit switch problem on my heater, do not know where to look for this switch [ 1 Answers ]

Have a limit switch problem do not know where to look for this switch

Primary limit circuit open [ 1 Answers ]

Consolidated furnace about 9 years old. I was informed that my heater isn't working so when I looked at the codes on the furnace I saw the light blinking 4 times which meant air circ.problem so I unplugged the unit and plugged it back in and it fired up. I let the unit circulate about 4 times and...

Primary limit swich [ 3 Answers ]

Where can I find a primary limit switch for my furnace - Guardian HW SV9500 ? I've checked all local stores but they don't have it. Thanks

Goodman limit switch/pressure switch? [ 2 Answers ]

Hi, I've got a goodman furnace (mod. # GHT070-3) it's about 5 years old. Recently, the heat will only kick on for about 30 seconds then shut off. It's giving me 4 flashes: Open limit switch, then it kicks off. After that it gives me 3 flashes and turns back on (pressure switch). It seems the...

Limit Switch - Pressure Switch [ 0 Answers ]

Hello Folks, This weekend I've been playing with a heating system at my new apartment and I'm trying to figure out what the different componets do. I kind of followed the circuit but still have some missing links... 1-There are some terminals on the furnace's circuit board labeled LIMIT. The...

View more questions Search