Natural Gas wall mounted heater, unvented / Need another source?

11 Replies

A bit of a novice here so please be gentle. I own a 1100 sq ft house in SC that currently has a Natural Gas wall mounted unvented heater for its primary heat source (1 unit). I have used this for 4 + years with no faults / failures and heats the house nicely. I am recently between renters and had the gas man in the house to turn the Natural Gas back on since the previous renter had turned off and out of their name. Gas man tells me that this is not supposed to be used as a primary heat source and he really is not supposed to turn the gas on unless there is another heat source in the house. Is this some sort of SC code issue?   He does turn the gas back on however this has my interest and I have been researching. Do I need another heat source? If so, I am so confused to the mass amounts of options that I am seeing. Most homes in this area (South Carolina) have central heat & air HVAC with duct work. This house does not currently have any duct work. From what I researched to put in HVAC system with ducts and all would cost me in the range of $6,000 to $9,000! Yikes. Since there is already gas in the house should I buy some sort of gas furnace? If so what kind? Is this vented? Not vented? I am just thoroughly confused at this point what to do, if anything?? Any help or recommendation would be greatly appreciated. As I stated I am a bit novice, only have 2 rental properties in my empire. Thanks so much.


Good start Mike welcome to Landlording. I'm in IN and it is not legal to have an unvented main heat source here. So if you are going to have a new system installed I would recommend not adding AC to save some cost, the ac system can be easily installed at a later date. If you didn't have ac before I assume they used window units. 

You may want to install carbon monoxide detectors as soon as possible. Just sayin...

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I live 20 minutes from woodruff. I put Heat pumps in my houses. I can have a heat pump and duct work installed for about 4k. Most older homes have crawl spaces so it isn't too hard to add the duct work. You can also run the duct in the attic if their is no crawl space.

I had a house setup like yours at one time and I never had anyone tell me that you couldn't use gas as a primary heat source.

You could also look into baseboard electrical heat but it isn't very energy efficient.

For a small house you could get a couple window A.C. units that are heat pumps and will cool and heat.

Lowes and HD carry these.

If this is a decent house with rents above $700 I would invest in a gas package unit which would heat and cool the house. Installed with duct work for around 4k. Message me if you need my HVAC guys number.

They are illegal here as well. We removed an ancient one when we rehabbed the SFR we have. But because it's a 1bedroom ranch with an existing electric HW tank we went with electric wall heating with blowers. I ran 240v from the panel & so far the electric billing has averaged $225/month winter.

@Mike Nicholson I would assume it is illegal because it will suck all the oxygen from the room and vent CO2 in place of it. They are used to heat garages in my climate, but only because it is outside the living area and opening the garage door gives frequent venting. It is dangerous for a living space. I would immediately install a CO2 detector and work on replacing the heater.

It probably hasn't killed anyone yet because in your warmer climate, it is not running continuously. Older properties have lots of air leaking in, so that helps with fresh air venting. But let's say you replace windows and seal the house up, then this heater could become deadly. 

Thanks everyone for the feedback!  I have been researching more today and have found a few options.  I did install CO 2 detectors when I first rehabbed the place a few years back.  I am leaning towards a wall mounted gas unit, vented, with a blower.  There is an old vent currently in the house which once vented an old wood burning furnace I am going to have a contractor look at and may be able to use.  If not I would just vent out of the top of the house.  Other options I have been looking at is baseboard heaters.   Thanks again for the feedback.  Nice to know there is a support group like this I can go to.

@John Underwood Hey John, can you provide me the HVAC company name and number.  I did not even realize there were gas systems that would heat and cool. 



We have a few of these. If I were replacing them I'd go straight to a ductless heat pump. It's the cheapest way to get heating and cooling and it's cheap for the tenant as well.

@Seth Borman   you a few of the vent free natural gas units?  If so, have you had any trouble with them? Gas company telling you can't use them.  Are they primary heat source in those rentals you have?



We just had to repair one of our two. $750 for new parts and the labor to install.

Ours are propane. No gas company involved.

If I had a way to profit from it I would install ductless units.

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