Suburban Furnace exterior vent types (with pic)

Common sense goes a LONG way when it comes to adding a screen. I for one have modified my intake and exhaust to include screens.

The heck with what the mfg's say!

I put appliance manufacturer's properly sized bug screen prohibitions in the same class as Onan's prohibition of exhaust addons like the Gen-turi. It's a "just in case" CYA clause that gives them an out when someone DIY's too fine a screen or adds too restrictive an exhaust extension, and then makes a warranty or damage claim. In Onan's case, their own extensions are longer and more restrictive than the Gen-turi elbow. Think "lawyer speak"...

I have run screens for years and never had an issue.

After a failure of the LR furnace I had to remove the furnace and do a lot of disassembling of the blower and heat exchanger just to find the dauber nest. It actually fell from the blower fan housing. It must have been blocking the sail switch because I seemed to have pretty good flow, even with the nest in place.

Anyway, the furnace got a good cleaning and I'm sorry, Mr. Suburban, but my newly installed screens are staying, whether you like it or not. I'm sure you don't recommend dirt dauber nests either. You just don't know they are there until they shut you down.

Does the Suburban furnace need wire-brushing once a year after use to keep it clean? Mine's 13 years old, and I've never cleaned it's interior grates.

Used to have a Vogue in the 1980s, and the furnace needed a good wire-brushing annually.

I've never pulled mine completely out except to reach in and around the interior to get at the mud dauber wasp nest because I didn't have the dual-screens installed on the outside of the unit.

The one that came with new unit is made for that unit. The tubes look to be different lengths. Being different doent mean better or worse. I can see that the new one might be a lot easier and cheaper to make, but not better or worse.

chuckbear wrote:

trailrider wrote:

chuckbear wrote:
That lip won't keep out more than a drop of rain. It is there to allow the install of a bug shield, which hangs on the lip and is secured by a spring. The difference in length is probably to allow it to fit in the new furnace and not the old one. Chuck

The lip isn't there to "allow the install of a bug shield." The furnace manufacturers specify in their manuals to never block the exhaust or intake of the furnace with anything, including screens.

Wow, Most every RV supplier out there, including Amazon must be totally unaware of that, including us and most RV's we have seen.
http://www.amazon.com/JCJ-M-200-furnace-Outside-Fitting/dp/B0002UHWIG

Chuck

Yep, I have one on my RV. Cleaning out mud dauber nests is nothing I need to do on a regular basis.

I cleaned out a furnace once that had a bird nest in the intake side of the furnace. The combustion blower fan was jammed full of little sticks and the bird even got around the fan and there were sticks inside the heat exchanger. It must have been the worlds smallest bird to get in there. The guy had been in California for a couple of months and he said he saw the bird doing it.

Whatever you do I would definitely suggest a pair of these. I just finished having to remove and clean my Suburban furnace to clean out a dirt daubber nest bigger than my thumb. It blocked the sail switch, not allowing it to close. Not a 30 minute job to get to the inside of the fan chamber.

I agree that the lip is also essential to direct the heat away from your painted surface.

chuckbear wrote:

trailrider wrote:

chuckbear wrote:
That lip won't keep out more than a drop of rain. It is there to allow the install of a bug shield, which hangs on the lip and is secured by a spring. The difference in length is probably to allow it to fit in the new furnace and not the old one. Chuck

The lip isn't there to "allow the install of a bug shield." The furnace manufacturers specify in their manuals to never block the exhaust or intake of the furnace with anything, including screens.

Wow, Most every RV supplier out there, including Amazon must be totally unaware of that, including us and most RV's we have seen.
http://www.amazon.com/JCJ-M-200-furnace-Outside-Fitting/dp/B0002UHWIG

Chuck

Aftermarket suppliers could not care what their products may do to a appliance. Suburban/Atwood/Dometic/Norcold all state to NOT add bug screens to the outside vents. The REASON is- they do not want the instake side to pull in weeping willow type debris that would block off the correct amount of fresh air required to get the LP to air mixture in correct burn proportion. On Refers, those screens block OFF up to 50% of the cool fresh air needed to correctly cool the refer. They all state adding those screens voids the warranty. I advise my customers to remove the screens when they come in if they have a problem with the appliance under warranty. We do not void if they have those screens and they are clear of debris. I have NEVER seen any real build up on those screens in all the years I have worked on RV's. Doug

Here's a screen shot of a new Suburban owners manual.