"Your furnace is garbage"

[DavidDeBord]

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Thanks for posting that VTP99.

[VTP99]

When i got the home it came from the roof jack got tired of it starving for air when we got a heavy snow storm its not fun cleaning the roof with you got winds whipping at you but you do what you have to do for heat.
So i changed it to under the house and yes its legal as well.

See page #3 ( venting requirements )

[Tony Gatto]

Mostly wont move enough air

[pctech]

it is against code and is illegal in most states in mine it is for sure its a long legal mess that we have to live with

[pctech]

yes it requires its own braned roof jack but most guys who work on manufactured homes carry a few of them as most are miller/interthem or coleman

[DavidDeBord]

One issue with stocking "Roof Jacks", especially when considering the many different lengths for each brand, & also the few "Special Applications", then compound the matter with the different Brands, from the "Nordyne/Globaltek Family", "Coleman", & even "Thermopride", has caused me to stock just a few odds & ends.

Over the last fifteen years or so, ... I've recommended to many Customers to go with a "Listed" Condensing Gas Furnace, which then adds another Furnace to the M.H. Family & that is Payne.

I can practically sell & install a Payne Gas Furnace, for what the "City Contractors" are selling/installing a 80% Furnace with Roof Jack for.

Sadly, .... M.H. Oil, has not made enough technological advances that would eliminate a Roof Jack, & ... It would be against HUD, & at the least Ohio State Code, to install a Residential Oil Furnace, with All Fuel Piping, in a M.H.

[pctech]

You are correct and miller makes one model that uses the two pipe system that is not a roof jack model.

[pctech]

[pctech]

look at the manual for the base pan for the CMF80Po it shows the two square knock outs for COMBUSTION air and yes its legal in my state you can chose the air comes in from the roof line via the roof jack or it comes in the COMBUSTION AIR cut out in the base pan mine was metal lined duct with the air intake hose firmly attached to it by the homes maker.
Manufactured homes have been built sold and installed in many ways but in my state they are starting to crack down on how the homes are built etc.

[DavidDeBord]

You are correct and miller makes one model that uses the two pipe system that is not a roof jack model.

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You are correct and miller makes one model that uses the two pipe system that is not a roof jack model.

I installed my last "Miller/Intertherm" Condensing Gas Furnace almost ten years ago.

"Right off th' bat", ... The Cheap Chinese Made Upper Limit would erratically kick open, for No Reason, during a Call for Heat, but to complicate the matter, that Upper Limit also was wired in such a fashion from the factory, that when it opened, ... It took out the Control Board!!

The Blower would run, & when the pre-set temp to close the contacts was reached, then the Board would re-energize, BUT, ... The Board would not show any Code!!!

I had to sit & watch this "sorry sack of %^&$#)(" operate for almost two hours beginning about 3AM about 45 days after I had installed it. I found that the Upper Limit was opening at approx. 85 degrees!

I then took out the Upper Limit, & added one of my stock "Button limits"so as to keep My Customer's heat on. That "Button Limit" operated properly & she had heat through that bitterly cold weekend.

Come Monday, I contacted ""Miller/Intertherm/ Nordyne/ Globaltek", whatever their Dsyfunctional Name is now, Tech Service, & pointed out the Issue of the Limit breaking power to the Control Board,resulting with the Board not showing any Code, & All that I got was a bag full of Bullcrap from them. All that they offered was to replace the Bad Limit, & told me that the Furnace was not to be altered!

I contacted the Clermot County Building Dept, & talked to the Head of the Mechanical Dept., & asked him what could be done. He told me that there was a "Grey Zone" in the Code over issues like this with M.H. equipment, that could not be directly addressed by the Mechanical Code, & that HUD, & other "Parties" had Control! I then entered the "Twilight Zone", going through State Boards, Federal Agencies & more, trying to find out, who could tell "Th' Dysfunctional Manufacturer" to correct this Issue that could cause harm to Life &/or Property. That's when "it hit home", that there are "Beings" that exist within the "Bodies of Power over Man & Inanimate objects", that don't breath, nor think, ... they just exist in their Civil Service Jobs to complicate Our Lives & Create Confusion.

Sorry about th' Rant, .... To solve the Issue, .... I installed a SP/DP Button limit, rated at the Factory Specs, set up so that when/If it opened, that it would allow power to the Board, but would de-energize the Gas Valve.

I Tested, Re-tested, & RE-Re-tested that set up, for "Loss of Blower", & "Loss of Power", & going in to the Tenth Year, there's not been any issue with an Upper limit.

But, ... I'll never, ever install "Miller"/"Whatever it is Today" again.

[pctech]

that's why i loved my CMF80PO simple set up no problems from day one until the day it work out about 30 years later with it being the original unit that came when the home was new and the replacement furnace is still going strong to this day as i see the present owner now and then to make sure things are still working

[DavidDeBord]

Does it have a roof-jack, from the Manufacturer?

[pctech]

sure does but the air intake is under the home as stated in page 3 of the install manual they put two square cut outs you can use for air intake and in my old home it was used when the second furnace was installed the first used the roof jack air itake but after a couple of good snow storms that got changed and yes it was approved by the manufacturer and the maker of the home as well as the local code inspector

[DavidDeBord]

pctech,

If You had a Roof jack, then the Combustion Air came from it. I understand the Snow problem, but Coleman & Nordyne/Miller/Whatever had & have Roof Jack Extensions that can be added to clear the Assembly out of the Snow, .... Most of the time.

About twenty years ago, WE had a Major Snow storm that dumped 32" of what was supposed to be "Flurries" that buried many a Roof Jack & Vent.

I've tore out Old M.H. furnaces that had that crawlspace intake, but never re-installed it with the newer furnaces.

[joemach]

Seller told her it had a brand new furnace and not to worry. Water heater just about ready to fall through the rotted out floor. Gonna go back Saturday and yank the heater and put it on a fresh piece of 3/4" plywood. She has no money to pay.

Sometimes it is just nice to help someone out. I have done it a few times. This has to be more than about money.

[pctech]

no it came from under the house after i disconnected the roof jack air intake and plugged it for good and used the cut out and lined it with duct metal and the maker aka miller said its fine its approved and my local inspector said its fine as well as most homes have plenty of air under them and in fact the newer homes the skirting has openings in it for that reason to keep the under side of the home from turning in to a mold pile like the older homes that did not have breathable skirting did mine did it originally but i tore out all the old belly insulation and had the rest of the home cleaned under neath and new insulation put in and a new belly cover installed and even changed from the old gray water piping to the newer pex piping .

[ThomOen]

One word. "YIKES"

[Poodle Head Mikey]

Does a concentric roof exhaust/intake increase efficiency by pre-heating the combustion air?

[rjk_cmh]

Does a concentric roof exhaust/intake increase efficiency by pre-heating the combustion air?

It's only concentric for about a foot or two, so I doubt it makes a difference.