1. Carrier Gas Furnace Installation Manual

I recently purchased a foreclosed house. The furnace appears to be new, or almost new. I have a feeling that the previous owner sold the furnace that existed in the house (he sold everything else), and the bank replaced it with this unit. As a result, I have no information on the furnace's history.

I'm having two issues, which I think may be related: Issue #1 is that the flame rollout switch is getting tripped. I reset it a few times (only while standing next to the furnace to make sure it doesn't catch fire). It trips within 10-15 minutes, each time. I've read that this could be due to intake restrictions, which leads me to #2. Issue #2 is that the filter (16x25x1) is horribly bowed when I pull it out. It deflects 2-3' after it has been used in the furnace for a day or two (the blower runs constantly after the rollout switch has been tripped). This is a 125kbtu, 5 ton furnace.

Is that an appropriately sized filter? All other large/high efficiency furnaces I have encountered have had much larger (3-5' thick) filters. I fear that the bank took the cheap way out when installing this furnace, and didn't do what was right for the situation. Any input would be greatly appreciated. I haven't been able to find a manual for the furnace to verify the amount of filter area that is recommended. That furnace has an unusually large BTU input, especially for a high efficiency furnace. But it may be properly sized, especially if it's in a large house or you have a cold climate.

The air filter seems undersized for a large furnace. If you have or get the installation manual for the furnace it will describe the kind of filter needed. There are two airflows through the furnace - the path the combustion gasses take on the inside of the heat exchanger and the path the room air takes flowing over the outside of the heat exchanger, absorbing the heat from the combustion gasses. There shouldn't be any mixing of those two air streams. So an undersized filter would not be causing the rollout swtich to open.

That would typically be caused by an impaired airflow of the combustion gasses. If everything is working properly, the combustion gasses flow into the furnace as fresh air, burn the fuel and flow out of the furnace as combustion gasses. An obstruction in that air flow will often cause the combustion gasses to start backing out of the burner openings, tripping a rollout switch. Thanks for your helpful reply. From what I understand, I should be investigating a possible obstruction in the vent? I did find the manual (jammed under the cold air return). I believe it specifies 2x 20x25 filters for the size furnace I have (I read it over the weekend, and don't remember the specifics, but it was definitely more surface area than what it has).

Clearly the filter is undersized. It also specifies that for 1600+ CFM installations that the cold air return should be in an upflow configuration (mine enters from the side).

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I have noticed that if I have one of those cheap filters (4 for $2, the ones that you can pretty much see through), the rollout switch does not trip. However, if I use a decent filter, it trips almost every time it runs. What could explain this?

Could the combustion area be in an overtemp situation due to less air flow with the more restrictive filter? It sounds like a lack of room air flow couldn't affect the flame pattern at all, by your description. I want to make it clear that I'm not challenging your statements. You obviously know significantly more than I do on the subject, which I appreciate. I'm just trying to understand the root of the issue. This is my first high efficiency furnace, so many pieces of it are new to me.

Based on these comments, I suspect that the limit switch which shuts off the burners if the furnace overheats is opening. Flame rollout switches have to be reset manually, by hand. Over temperature limit switches reset after the fan continues to run and cools off the heat exchanger.

Do you understand which switches are limit switches and which are flame rollout switches? Describe in more detail what is happening when your furnace is operating. The code the furnace gives is flame rollout switch open. The switch is about the size of a dime, located near the combustion area. It has to be reset by hand (with a small button between the two wires). From everything I've read, it must be the rollout switch that's being tripped, but I don't understand why. The blower will run continuously until this is reset.

The furnace power needs to be cycled after resetting the rollout switch in order for it to operate normally. Can an overtemp situation trip the rollout switch? Or can it only be tripped by the flame actually rolling out?

Leave it to me to have a furnace that breaks all the rules. I looked in the end of the vent as best I could yesterday, and I couldn't see anything inside of it. It's one of those vents where the two pipes combine just inside the exterior wall of the house, and it has a hat on the pipe outside, so I can only see one of the pipes. If I'm understanding you correctly, the vent.should. be the only place that a clog could cause this behavior, right?

If so, I'll see if I can figure out a way to verify that it's clear all the way back. It's about a 25' run, and it does not have a screen on the outside, so anything's possible. No, something can be plugged up pretty much anyplace on the air intake line, the combustion gas line or the heat exchangers inside the furnace. To add to the fun, an inducer motor running slow, deteriorated or plugged inducer motor fan blades or cracked heat exchanger can cause the problem. Water pooling in the vent pipes or obstructing drain lines can cause the problem.

While I wouldn't ordinarily expect a new furnace to have a cracked heat exchanger, the fan circulating air around the house should NOT be affecting the way the flames are burning, which you seem to be reporting. In short, a wide variety of often hard to detect problems could be the cause of your difficulties.

I think that the key here is that the old furnace was taken out,and a new one installed by somebody in a hurry who did not size it properly. All new 80 percent and 90 percent furnaces have a designed temperature rise on the furnace nameplate. You start the furnace,put a thermometer in the return and one in the supply duct per manufacturer and check the temp rise.example 35 degrees to 60 degrees. If your return temp is 70 and the supply temp is say 45 degrees plus 70 you are within the temp rise design fo the furnace. If you are not within the design temp rise,you must adjust the blower speed.

Lets say you are only getting 20 degrees temp rise.you need to put the blower speed on a lower one to bring the temp rise up. This stpe was probably not taken whe the furnace was installed.

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We suggest not registering using an AT&T, BellSouth, AOL or Yahoo email address. If you have any problems with the registration process or your account login, please. I purchased a 90% efficient condensating Concord furnace, model number 95G1UH090CP16 in mid-October of this year with a Honeywell programmable thermostat. When it was installed in October, the weather was mild (in the 50s) and the furnace worked great. However, now that it's December and has gotten quite cold in New England, the furnace is on the fritz despite being brand new.

The plumber who installed it (and another guy from the same company) has been out to try to fix it, and cannot figure out what's wrong with it - an HVAC repair guy from a different company was out, and cannot figure out what's wrong with it. The plumber called Concord Tech Support, and they couldn't figure out what was wrong with it - but I haven't had heat for 2 weeks despite temps below freezing, and I have a 1 year old son, so I'm getting a little desperate here.

Here's what I know: - There is 18 feet of piping and 4 elbows (5 elbows allowed with up to 19 feet of piping, so we're below that) - Everything is properly pitched toward the furnace - The drain piping etc appears to be installed correctly, and drains into a condensate pump that appears to be functioning properly - There are no clogs/debris in the intake or exhaust pipes. There is no soot/dirt clogging any parts, it's only been in use for a month and a half - By all appearances, there is nothing wrong with this furnace except for the fact that it doesn't work The symptoms: - If the temps outside are mild, the furnace works fine and keeps my house at the set temperature with no issues. If it gets cold, the following happens: - Fan turns on, burners ignite, everything works properly for anywhere from 30 secs-3 mins. Then everything shuts down, blower turns on. It doesn't get nearly warm enough to get the house up to temp, but everything turns on and appears to be running properly while it's running - Sometimes a pressure switch error that indicates the pressure switch trips while the inducer is open (3 blinks) gets thrown. Other times, it's just a solid light, indicating no problem at all (even tho there clearly is one) - There is water getting into the inducer fan.

I do not know where it's coming from. According to the Concord tech support guys, it's not possible.

He said the only reason for water in the inducer fan is that the furnace is double trapped (it's not - we did have the drain pipe in the hole of the condensate pump, but it has since been moved to make absolutely sure it's not touching the water when it rises) - The furnace doesn't drain while it's running, but I believe it should. It drains after the burners go out and everything shuts down - There is no lock out; if I set the thermostat high (in the mid-70s or 80s) the furnace will kick on and off every half hour or so, but it only runs for a little bit before going out. If I turn the temp down on the thermostat until the request for heat turns off and then turn it back up so the request for heat comes back, it turns the furnace on - I do not need to manually turn power on and off to the furnace, the thermostat does its job, but the furnace only runs for a little while each time - It is not a thermostat issue, as jumping the wires doesn't solve the problem - The pressure switch appears to be operating properly, as does the sail switch and the rest of the furnace. There's clearly a drainage issue due to the water in the inducer, but everything appears to be installed properly and the condensate pump is working - also, if it wasn't hooked up properly, it wouldn't work fine in warmer weather I'm not even looking to DIY this, but I'm not sure what to do at this point - 2 plumbers, an HVAC guy, and the Concord tech support dudes are stumped, and I'm frickin freezing.

I have a brand new furnace and no heat - the place I bought it from has a guy who's Concord certified, but he's on vacation for another week (of course). Does anyone maybe have ANY insight that I can pass along to the pros as to what could possibly be wrong with this furnace?

Thanks in advance. The plumber who installed it (and another guy from the same company) has been out to try to fix it, and cannot figure out what's wrong with it. That may be your entire problem right there. Time to time you get a bad: furnace, coil, condenser. Gmc terrain manual for 2017. If that happens you usually swap it out and get it running.

A few weeks ago I had an issue with something and I had to call support, still could not get it to run, so they sent out their troubleshooter and found the issue and got it up and running. If all is accurate, and if your installer is licensed to do HVAC work, you should be able to ask your installer to contact Concord and have them send out thier troubleshooting Specialist, they should be more than happy to do that. Do this: email this guy with this information. Removed E-mail. He is their head tech troubleshooter and a good friend of mine. See if you can arrange for a good smart tech hvac guy (not a plumber, sorry) to be there and have him call in to tech support to talk to Kyle at a pre determined time. Kyle is in Columbia SC, so he is in EST.

Also take notice of the flashing lights that indicate what the problem is.take note of the # of flashes, make notes. Try to have the install manual handy. The drain instructions are very specific. Is there a TEE in the drain? Perhaps all should be unhooked and re-done. IF the furnace is going out on limit, the flashing lights will indicate that. These are very good products, something is being missed unless there could be something partially plugged inside the unit.

Last edited by jpsmith1cm; at 07:02 AM. A few weeks ago I had an issue with something and I had to call support, still could not get it to run, so they sent out their troubleshooter and found the issue and got it up and running. The plumber did call Concord, and they won't send anyone out directly - they did train/certify someone from the supply house we purchased the furnace from to be a Concord tech, but that guy is on vacation for a week right now unfortunately. So we're in a holding pattern, and we're going on the 3rd week without heat:/ I'm hoping we can get SOMEONE to come out - will be on the Concord rep's ass all day! Joe, they've been studying the manual and think that all the hoses etc are correct - if they weren't correct, would the furnace run properly in mild weather?

It's definitely something to do with the weather dropping below freezing - if it's 50 outside, everything runs great. It's a vertical/horizontal furnace, but we have it installed vertically - I believe it is an upflow (the exhaust and intake pipes are installed at the top and drainage pipes on the left side). I'm not at home now (can't hang there with the baby, it's 54 degrees) but will try to snap some pics this evening. There's really not much to see tho, you can't actually see the water. Is it possible that there's a problem with an airlock in the collection box? It doesn't seem to drain until AFTER the furnace shuts off, at which point you can turn it on again (but it only runs for a little bit, not long enough to get anything warm). Jtrammel - Drain piping seems to be ok, but it's always possible - however, I don't think it's reaching a max temp, because it's only burning for 30 seconds to 3 minutes.

It's running longer in the warmer months to get the house up to temp than it is now, because it's shutting off WAY before it's up to temp in the cold months - is it possible that it could be overheating in as little as 45 seconds of burner time? Bha - the email addy was removed! Can you add spaces, or spell out the AT instead of writing it like an email addy? I'd love to reach out to him. I don't think there's anything plugged in there - it's so new that I can't imagine what could have gotten into it, and all the pipes and tubes seem to be clear. But it's always possible that something was hooked up improperly - sometimes the LED isn't throwing an error at all (just a solid light indicating that everything is running well) and sometimes it blinks 3 times indicating a pressure switch error with inducer open.

Do either you (ga) or bob have the Allied Air tech support number handy? I have the number for my region's sales director - but I'll do some Googling and see if I can track Kyle down in the meantime.

Cross your fingers. Thanks for your help, guys! Most of us in the heating and AC world know that installation is more important than product or price. This sounds like what myself and endless professionals see: Someone bought a replacement furnace (or system) based on price rather than qualifications. Now it does not work when the weather is extreme (extreme hot or extreme cold). I have been to the manufacturing plants of many heat and AC co's and I can tell you from PERSONAL experience; AlliedAir makes good products and their quality control is one of the highest in the industry. I might also add one of the biggest names in the industry also has the highest number of warranty claims.

I really am sorry you are having issues, nothing is perfect. Give Tech support a call, ask for Kyle, have the stuff noted available. Best to you, hope you get it working. Nevermind, brain fart. We've been calling the Allied Air tech support line - not sure if we've spoken to Kyle or someone else. So we have that number I'll call back and see if I can reach Kyle directly - the guy we talked to last nite couldn't figure it out, said he'd never heard of the symptoms we're having, and referred us to the supply house where we bought it (who has a certified Concord tech, who is on vacation this week).

I'll post some pics this evening and you guys can see if it looks right to you - we're thinking that since it's not draining until after everything shuts down, maybe the inducer fan is creating a vacuum in the collection box and preventing the water from the secondary heat exchanger from draining until the fan goes off and the vacuum is broken - does that sound at all possible to you? Joe, they've been studying the manual and think that all the hoses etc are correct - if they weren't correct, would the furnace run properly in mild weather? It's definitely something to do with the weather dropping below freezing - if it's 50 outside, everything runs great. It's a vertical/horizontal furnace, but we have it installed vertically - I believe it is an upflow (the exhaust and intake pipes are installed at the top and drainage pipes on the left side). I'm not at home now (can't hang there with the baby, it's 54 degrees) but will try to snap some pics this evening. There's really not much to see tho, you can't actually see the water.

Is it possible that there's a problem with an airlock in the collection box? It doesn't seem to drain until AFTER the furnace shuts off, at which point you can turn it on again (but it only runs for a little bit, not long enough to get anything warm). Jtrammel - Drain piping seems to be ok, but it's always possible - however, I don't think it's reaching a max temp, because it's only burning for 30 seconds to 3 minutes. It's running longer in the warmer months to get the house up to temp than it is now, because it's shutting off WAY before it's up to temp in the cold months - is it possible that it could be overheating in as little as 45 seconds of burner time? Bha - the email addy was removed! Can you add spaces, or spell out the AT instead of writing it like an email addy? I'd love to reach out to him.

I don't think there's anything plugged in there - it's so new that I can't imagine what could have gotten into it, and all the pipes and tubes seem to be clear. But it's always possible that something was hooked up improperly - sometimes the LED isn't throwing an error at all (just a solid light indicating that everything is running well) and sometimes it blinks 3 times indicating a pressure switch error with inducer open. Do either you (ga) or bob have the Allied Air tech support number handy? I have the number for my region's sales director - but I'll do some Googling and see if I can track Kyle down in the meantime. Cross your fingers.

Thanks for your help, guys!You are on the right thinking track in your first paragraph above. A condensing furnace (like yours) should make literally gallons of water every night when it is freezing outside. It can make as much as a pint in that 3-4 minutes before shutdown.

Go back through your entire furnace drain system. Think of the simple reality water runs downhill. Yeah, I now that may sound condescending. Not meant to.

Carrier Gas Furnace Installation Manual

There is something impeding that downhill flow of water, causing the safeties to shut down the furnace. Send us the picture. Lots of pictures. Tell you what: I may get in trouble with the forum mgt.

However a cold baby is not a good thing; Click on my screen name and send me an Email. If all else fails, sometimes you have to try repalcing the control board. I'd lean that way because it's shutting down at times without throwing a fault. That shouldn't be possible unless the call for heating ends.

Maybe try running it using indoor combusiton air. Where it is located? IF in a basement you coudl insert just a short 2' peice of pipe wiht 1 elbow for the combustion air inlet. IF its' a closet, jsut leave the closet door open so it has plenty of air. Actually.taking a tep back, is only hte exhaust vented outdoors? OR are both piped outdoors? We definietly need photos.

You might have a a negative pressure indoors near the unit. Could be caused by even stack effect expecially if you have a firepalce chimney that's not sealed or lots of upstairs air leaks. The 1st floor can become slightly negative. Add in a marginal piping (you said it was only 1' 'in reserve' for the vent length. Quick Navigation. Site Areas. Forums.