Question about Goodman GMS90703BXA Heater

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Where does the Oxygen for combustion come from- Indoor or outdoor?

Is there a separate feeder tube that feeds oxygen from outside for combustion or does the speace heater take indoor oxygen for conbustion?

I live in an apartment in Buffalo and I think I got a Goodman natural gas heater with model number U-18L.

I've been having a little shortness of breath that is concerning me. I would appreciate your answer.

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Re: Where does the Oxygen for combustion come from-...


Gas heater normally get air for combustion from the outside as seen in this diagram.

Hope this helps...and hope you feel better soon!

Posted on Jan 18, 2008

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When I light the water heater only a yellow flame burns. There is soot in the flue also. Adjusting the air shutter has no effect...

Incomplete combustion - insufficient oxygen or contaminated gas supply. Best to call hvac person.

Jun 02, 2016 | Heaters

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Propane turbo heater. After awhile why does it start to burn eyes and nose?

Hi Eric

It sounds like the heater is getting the air in the room so warm that it's making your eyes and nose hurt. That can be from dryness, from heat, or from combustion products.
Depending on the partucular model, you can try to:
  1. Turn the set temperature down.
  2. Turn the turbo fan to a lower setting.
  3. Turn the feed valve from your propane tank to a slower feed. At some point, you should be able to throttle the amount of fuel burning in a period of time to where the heat is more bearable.
  4. If you're smelling fuel, or overt burning petroleum smells, turn the unit off. This is a sign that things aren't burning right.
Last, but probably most important. If you are running a unit like this inside, make sure you have windows open. Please take me seriously here - installed propane furnaces have heat exchangers to pull in fresh air, heat it, and pass that air into your house. A propane heater burning inside your house is burning your inside oxygen and, depending on the flame quality, dumping Carbon Dioxide or, worse, Carbon Monoxide, into your house. You can end up dead pretty quickly, especially from Carbon Monoxide poisoning, and you'll likely be feeling fine right up to the time you pass out. These types of heaters are meant more for outside use, so please, if you absolutely feel you must run it inside, keep windows open and have a fan running. You're playing with your health

Good Luck!

Nov 24, 2015 | Heaters

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Is the monitor 422 heater considered a direct vent wall heater

Yes, the Monitor 422 heater is direct vent type.

You must install the supplied double-walled vent tube between the heater and outdoors. Failure to properly install the vent tube will quickly deplete oxygen from the space it is operating in. That is a potentially deadly situation.

The pipe is special. The inner pipe is for hot exhaust gasses to be sent outside and the outer walled pipe is for fresh combustion air to be brought into the heater. This set up is why the heater does not create drafts in the home.

Apr 17, 2015 | Heaters

1 Answer

My gas fireplace shuts off after burning about five minutes - both main burner and pilot shut off.

Most fire place burners have an oxygen depletion sensor on them nowadays. If you can restart it after a while, a few minutes or so, and shuts off, it is probably the oxygen sensor. The owner lights fireplace and shuts the door, and the fire depletes the available oxygen and the fire will start producing copious amounts of CO which is a hazard. Most fireplaces have a fresh air supply available to provide combustion air but needs to be opened for the fireplace to work properly. Check the manufactures recommendation as to the proper installation of the fireplace furnace.
Hope this helps

Feb 05, 2015 | Heaters

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Why do we have incomplete combustion?

For combustion you need the right amount of oxygen and air, so, may be, you need to open the entrance of air, the primary or secondary opening.
You can have wrong winds and pressures reversing the direction of movement of air in the chimney ?
Your chimney is full or closed ???
All is function of the details observed very carefully.

May 11, 2014 | Heaters

1 Answer

My rinai gas heater is not reallly lighting up though gas flow seems alright

Gas also requires oxygen to burn, perhaps there is an issue in an air feeder or mixing valve some where in your piping or if there is an inlet for air ensure that it is not obstructed. Using any combustion device in a confined space can be problematic for health reasons and the combustion process due to a finite oxygen supply. I hope this helps your investigation.

Apr 17, 2014 | Heaters

1 Answer

Is there any possibility my Rinnai econoheat850 gas heater can give off carbon monoxide?

Any time there is combustion of any type fuel, from a Rinnai heater to a car engine. There is always a small amount of Carbon Monoxide given off. But, it's usually in small insignificant amounts.

Since your model is a Vent-free or flue-less model, the chances are a little higher. This usually occurs if the heater has not been properly and regularly maintained. Keep in mind, flue-less heaters take in household air for combustion, heat it and send it back out. Whatever is floating in the household air (duct, lint, pet hair, etc) is pulled into the heater. These things can clog the burner(s), the pilot and the Oxygen Depletion Sensor (ODS) and cause incomplete combustion. Which translates into higher than normal Co levels. However, your unit is equipped with an ODS, that will shut the gas off to the heater, if the household oxygen level reaches 25%. Which is not the danger level, which is 19%. Once the Oxygen level returns to 30%, the ODS will release the gas valve and gas will return to the pilot, so that you can relight it.

When properly maintained and operated according to the Owners Manual (see link below) they are totally safe. In the last 20 years, millions of vent-free/flue-less heaters have been sold and operated throughout the world. There has never been a death related to their use.

Certainly, if you or your family think you are experiencing signs of carbon monoxide poisoning, stop using the heater and have a qualified Rinnai technician check and service the heater. If you have other gas appliances in the house, it may be one of them causing the symptoms and not the heater. You may want to have those check and serviced, too.

I hope I was able to help you. Please let me know. Thanks.

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Reddy heater shuts off after less than ten minutes of operation

Probably need to make sure you have enough combustion air/
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Mt Rinnai convector 516tr will not start, have stored it away for summer got it out for this winter plugged all in after pressing start after about 20 seconds No 11 starts flashing

I have had this problem due to the heater 's combustion sensor concluding that all was not well. In my case, the heater had burned up too much of the available oxygen. I didn't notice the lack myself, so it must be very sensitive. I had shut the place up to keep the heat in and eventually it dawned on me to open a door for a minute or so every half hour or so to replenish the oxygen supply.

The situation is worst when the place is very cold as the heater will roar away trying to heat it up as quickly as possible. After I came back for a holiday in winter, I had to set the temperature down to "L" and "Economy" on plus run an electric fan heater for a day to warm the structure to the point where the gas heater could relax and not burn oxygen faster than it could heat the space.

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Glo warm heater

These are vent-free heaters and use an oxygen-depletion sensor to shut a unit off if there is not a sufficient amount of oxygen available for combustion. It is either doing it's job and you may have to open or crack a window while it's operating.

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