Announcement Announcement Module
Collapse
No announcement yet.
Gas Fired Forced Air HVAC Problem Page Title Module
Move Remove Collapse
X
Conversation Detail Module
Collapse
  • Filter
  • Time
  • Show
Clear All
new posts

  • Gas Fired Forced Air HVAC Problem

    Friend of mine called me this morning asking my opinion on how a HVAC co. is charging him and the problem he is having. Here is the story.

    Carrier 4 ton carrier horizontal gas fired forced air unit in the attic. The unit quit working during the night a few weeks ago so he calls the HVAC repair company and they come out. He checks for 30 minutes and tells my friend that he cant find anything wrong with it.....my friend says well there has to be somthing wrong because it quit working......and now its working after you got here. The service guy then said well I did turn the power off to the unit and back on....the unit then fired up as normal. My friend protested that he thought somthing was wrong and that its never done that before. He paid the guy 115.00 for his time and that was that.

    Fast forward one week. My friend woke up to a cold house. Called the heating guy back and they came out to check the unit. They again said they couldn't find anythign wrong. My friend protested and one of the service guys said.....'let us check one more thing" WTF???? two visists and he still has somting else to check? Ok so the guy comes out of the attic and says the "circuit board or brain of the unit must be bad....its 650 to replace it with labor and the board. My friend agrees and pays the money and they change the board.

    Fast forward 2 weeks.......friend wakes up to a cold house and calls the HVAC company back and they come out. They go into the attic and come back down after about 20 minutes and say that the gas control valve is sticking and needs to be replaced......the cost to replace the gas control is 350.00 and they claim they are not charging any labor.

    So what do you think about the problem? What do you think about how the service guys went about the job?

    Thanks for your help.

  • #2
    Re: Gas Fired Forced Air HVAC Problem

    If it was me...they wouldn't get charged until I knew the problem was fixed. Shooting in the dark and taking shots, is just bad business IMO.

    I'm not familiar with Carrier per say, but pretty much everyone has the same components inside.

    If the gas valve and main board were replaced, it sounds like a safety issue check that could be the problem.

    Was the pressure switch checked? If it's starting to stick, it's possible for the unit to light once in awhile.

    I'll let someone more familiar with Carrier chime in, as I'm curious as well.

    Comment


    • #3
      Re: Gas Fired Forced Air HVAC Problem

      Originally posted by Flux View Post
      If it was me...they wouldn't get charged until I knew the problem was fixed. Shooting in the dark and taking shots, is just bad business IMO.

      I'm not familiar with Carrier per say, but pretty much everyone has the same components inside.

      If the gas valve and main board were replaced, it sounds like a safety issue check that could be the problem.

      Was the pressure switch checked? If it's starting to stick, it's possible for the unit to light once in awhile.

      I'll let someone more familiar with Carrier chime in, as I'm curious as well.
      The HVAC duys replaced the gas control valve this morning. Everyone assumes now that was the problem. Time will tell. This same company sevices the unit any time theres a problem. In the past the main circuit board needed to be replaced.....that was 5 years ago. No problems until recently. The unit is 20 years old and in great shape...or so the same HVAC guys say.

      Comment


      • #4
        Re: Gas Fired Forced Air HVAC Problem

        Why didn't the HVAC tech "test out" the gas valve before hand?

        Comment


        • #5
          Re: Gas Fired Forced Air HVAC Problem

          Originally posted by Flux View Post
          Why didn't the HVAC tech "test out" the gas valve before hand?
          It is my understanding that they can work for a period of time and then stick closed.....it never did stick until today while he was there. So it was an intermittant problem.

          My problem is that he replaced the main circuit board....Now how did he test that? I think they jumped the gun on that repair/replacement....Hoping that was the problem. Thats an expensive "shot in the dark"

          Comment


          • #6
            Re: Gas Fired Forced Air HVAC Problem

            Yes indeed ...Atleast the hvac guy wasn't trying to bend the customer for a new unit..Alot of guys will you know..
            ''Beer is proof that God loves us and wants us to be happy" Benjamin Franklin

            Comment


            • #7
              Re: Gas Fired Forced Air HVAC Problem

              honestly, dumping a thousand dollars into a 20 year old unit seems a bit foolish to me. at that age, I'd have been hard pressed to agree to change the $650 control board.
              No, it's not rocket science, it's plumbing and unlike rocket science it requires a license.

              Comment


              • #8
                Re: Gas Fired Forced Air HVAC Problem

                Originally posted by MoJourneyman View Post
                honestly, dumping a thousand dollars into a 20 year old unit seems a bit foolish to me. at that age, I'd have been hard pressed to agree to change the $650 control board.
                Honestly,650 sounds better than 5 or 6 grand when we only use the heat around here a few months out of the year.

                Comment


                • #9
                  Re: Gas Fired Forced Air HVAC Problem

                  valid point, forgot you were in the swamp.
                  here, if I've got to put that kind of money into a repair, I'm suggesting replacement.
                  No, it's not rocket science, it's plumbing and unlike rocket science it requires a license.

                  Comment


                  • #10
                    Re: Gas Fired Forced Air HVAC Problem

                    Sounds like the service tech needs a little schoolin.

                    Checked out a Carrier furnace this weekend with an intermitent problem.
                    The problem turned out to be the plenum limit switch. I checked it with an ohmeter it was reading around 3ohms. Which was enough resistance to keep it from running.

                    Another common problem is the flame sensor.

                    Comment


                    • #11
                      Re: Gas Fired Forced Air HVAC Problem

                      Originally posted by James P View Post
                      Sounds like the service tech needs a little schoolin.

                      Checked out a Carrier furnace this weekend with an intermitent problem.
                      The problem turned out to be the plenum limit switch. I checked it with an ohmeter it was reading around 3ohms. Which was enough resistance to keep it from running.

                      Another common problem is the flame sensor.

                      Ok update. The HVAC guy came back out and replaced the gas control valve yesterday.

                      The unit still is still firing some times and not firing other times.

                      The units fan motor will run for a few minutes...the unit will not fire and then it shuts itself down.

                      Its a carrier horizontal gas fired unit. Model Number.....58DHC095111LC.....or the last two digits could be 66

                      Comment


                      • #12
                        Re: Gas Fired Forced Air HVAC Problem

                        Check the gas pressure.


                        J.C.

                        Comment


                        • #13
                          Re: Gas Fired Forced Air HVAC Problem

                          When you say the units fan motor are you talking about the blower motor or inducer? The blower won't come on if the burners haven't fired. I would check the inducer and make sure it's spinning freely and doesn't have a layer of dust on it. Try jumping the pressure switch. Check that the HSI is glowing white hot. Sometimes those things will crack and only heat a little bit.

                          Comment


                          • #14
                            Re: Gas Fired Forced Air HVAC Problem

                            Originally posted by plumberscrack View Post
                            When you say the units fan motor are you talking about the blower motor or inducer? The blower won't come on if the burners haven't fired. I would check the inducer and make sure it's spinning freely and doesn't have a layer of dust on it. Try jumping the pressure switch. Check that the HSI is glowing white hot. Sometimes those things will crack and only heat a little bit.
                            Ok I called her and it is what you must be calling the inducer......no air blows from the vents. Thank you. To jump the pressure switch I disconnect the two leads and install a jumper wire in their place? Please be patient...I know nothing about this shiot....and thanks for trying to help.

                            What else can I check? The brain control board,gas control valve,1/2lb pressure regulator have all been replaced......still doing the same thing.

                            James P said check the plenum switch...is that the same as the pressure switch?

                            Comment


                            • #15
                              Re: Gas Fired Forced Air HVAC Problem

                              Originally posted by TheMaster View Post
                              Ok I called her and it is what you must be calling the inducer......no air blows from the vents. Thank you. To jump the pressure switch I disconnect the two leads and install a jumper wire in their place? Please be patient...I know nothing about this shiot....and thanks for trying to help.

                              What else can I check? The brain control board,gas control valve,1/2lb pressure regulator have all been replaced......still doing the same thing.

                              James P said check the plenum switch...is that the same as the pressure switch?
                              Plenum switch is not same as pressure switch. It's the limit switch that controls the air temp in the duct.

                              You can try jumping the pressure switch BUT you probably have to do it AFTER the inducer powers on. Once it shuts off you have to break the connection again before it will fire again. Does this makes sense?
                              It's set up this way so in case the pressure switch sticks in the closed position.

                              I'm sure you have a manometer. Check gas pressure against specs on unit.

                              Comment

                              Working...
                              X