Welcome to Q&A for Home Maintenance Q&A section, where you can ask questions and get answers from me and other members of the community.

Spam, self-promotion, questions with abusive, inappropriate language, and irrelevant questions will be deleted.
All of the questions are moderated!

You'll be notified when your question is answered. Please reply with Feedback to share whether a solution worked or didn't work. Thank you!

Connect on Google+
Find on Google+ Local

Does anyone still make in-ceiling natural gas furnaces?

0 votes

Richard says:
Saturday, November 19, 2011 5:55 PM


You discuss improperly installed condo gas furnaces above ceilings... can you tell me who makes them? Does anyone still make in-ceiling natural gas furnaces? Mine is a "Suburban" (we think) DCF-30M* ...and nobody here seems to know of any replacement ceiling units.

asked in Heating System by darekrudy (21,730 points)
edited by darekrudy
Share this question on your favorite network.

1 Answer

0 votes


Hi Richard,
I cannot find this particular furnace model, the only information that is showing up in search is for Suburban DCF-30G residential furnace that was manufactured first time in 1987. There are many Suburban furnaces available for RV’s but those would need to be converted from LP to natural gas.
Most if not all of the furnace manufacturers make gas furnaces which can be installed horizontally above the ceiling. Installation would depend on the amount of space available above your ceiling to accommodate this new appliance, configuration of air ducts, the vent pipe, and overall location of the furnace area. 
If you can fit one in the same space that your old Suburban furnace currently occupies, your choice would be between a high efficiency unit which utilizes PVC pipes for venting and combustion air supply. You wouldn’t need a chimney, just a way of getting two PVC pipes to the exterior (through the side wall or roof).
Second option, a horizontal, regular efficiency furnace using existing chimney and combustion air from the interior of your house.
You would probably need to get a heating contractor to check your current installation and look for a unit that would fit into that space.
Let me know if you have any other questions.
answered by darekrudy (21,730 points)


From: Richard D
Sent: Monday, November 21, 2011 5:25 AM
Thanks for the reply... 
As you noted, I also was unable to find much info online about the DCF-30M* model... but I've seen the model number referenced along with others, for parts, on various websites... with the brand name "Suburban".  I was surprised to learn that this furnace is apparently an RV heater?
  (That asterisked model number is stamped on an info plate on the furnace. Wonder if that indicates a conversion to natural gas. I guess I will try to contact 'Suburban'.) Unfortunately, the ceiling was painted with the furnace cover off, so it's hard to read some plate info and the wiring schematic, due to paint overspray.
It seems that furnace is now 'obsolete', and there is uncertainty about local building codes allowing this kind of installation anymore and whether there are 'grandfather rights' to replace the unit with something similar.  Seems replacement is at condo owners' expense and responsibility to find a solution. 
The condo association has some spare parts (but not all, like the specialized electric gas valve), and if the unit fails, they are at a loss for replacement information apparently... other than disconnection of the unit and options to use a fireplace insert, or an expensive boiler/baseboard retrofit alternative.  It's a tight fit, these are very small condos and giving over a closet to a boiler/baseboard retrofit is not a great idea, especially as I was given a rough estimate of well over $10,000, which is a very expensive fix for these units. I would have to choose the fireplace insert... the good thing about being on the top floor, I get the benefit of heat rising.  
It's also unknown if we can put a newer, 'regular' furnace above in the 'attic' space... the current installations are about 16ft from the exterior wall, the roof is not flat.  I don't know about lower floors, but top floor condos might find that a more cost-effective solution, if it is possible.
These ceiling installations have been in place since probably 1985... with metal 1-3/4" o.d. piping, exhaust and intake, out the exterior wall.  On the top 3rd floor of the condo complex, the exhausts extend past exterior wall, not quite 3ft out the eave, while the intake is just below the exhaust but ends about 3 inches from the exterior wall.
Unfortunately for the top floor condos, the exhausts do not extend beyond the deck... so in winter, we have condensate drips building up ice mounds on the decks, sometimes to the point of an icicle extending all the way back up to the exhaust pipe, if one does not perform preventive maintenance on such icing, which can accumulate 6" of ice in one day. (Lower floors exhausts extend across the bottom of upper decks and the condensate drip ice forms down to their railings, rather than onto their deck.) 
I tried a 2ft PVC extension to move the drip outboard of the deck, to the ground, but it ices up... the drip forming a dangerous stalactite on the end, and sometimes the ice extends back into the extension if not cleared regularly ...while the existing metal piping doesn't ice usually, just drips. So, when there's ice in the extension, it apparently trips an exhaust pressure sensor that constantly shuts down the furnace. I suppose I could try wrapping some kind of thaw cable on the PVC to keep it clear.
All this just makes me want to move and sell the place.  Seems to me that the condo association should bear the burden of replacing aging furnaces... but I don't know the legalities. I may look into the possibility of a newer "Suburban" RV furnace... (or other brand?) ...just for everyone's info.
Thanks for the comments... any other advice appreciated. ;)


Hi Richard,
Akismet marks everything as spam for some reason but I did set it up to deliver it anyway. 
Suburban used to make residential furnaces as well - http://www.furnacecompare.com/furnaces/suburban/DCF-30G.html.
 A while ago it appears that they’ve abandoned them and decided to concentrate on RV models only.
I believe that your options would greatly depend on the condo’s association decision on allowing you to perform any heating system upgrades that expend beyond the unit itself. If they would allow attic installation and if there’s some extra space directly above the area of your current furnace installation, there shouldn’t be a problem with getting a new, slightly larger unit. 
Another issue would be to get a vent pipe or pipes (with a high efficiency furnace) through the roof or side wall. That might be a problem because it affects an overall appearance of the building and some associations might be against it.
You could also go with an electric forced air furnace if your current wiring (electrical panel location, size / capacity) and electricity rates in your area are better than the natural gas prices, or at least similar. With electric furnace there would be no problems with condensation and icicles.
Fireplace insert… check with your local building department if such would be considered as a permanent (per code) source of heat in your unit. Otherwise it could compromise your real estate transaction in the future. 
Anyway, you probably have to start from contacting your local authorities and find out about current code requirements in your area (using converted RV furnaces and fireplace inserts). If they wouldn’t allow those RV furnaces anymore find out from the association about expending into the attic, making holes in the roof or wall, or using electrical appliances (you’d need 220V for that and there might not be enough power in your electrical panel to handle it.
Also, I’d have a heating technician to look at a heat exchanger of your old furnace. Direct vent furnaces (their heat exchangers) tend to corrode heavily and if there are holes in it… well, you might be putting your life in danger. 
Heat tape on a PVC vent pipe is a risky solution because it might melt. 
Let me know how is this whole thing proceeding.