help with a old furnace

Repair help for the do-it-yourselfer.
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Posts: 72
Joined: Mon May 23, 2011 5:59 pm

Sat Sep 15, 2018 7:17 am

I am looking for some help, I have older mobile home with a vintage Miller CMF Model FS-LS furnace the, roof vent pipe has started to fail and they do NOT make any new parts for these furnace's
the main roof vent cap, rotted out a a ton of rusty metal has fallen into the furnace, (possible need a whole new roof jack) my regular furnace cleaning guy has little to do experience with mobile home furnace's, and is scared to even try and open this up to clean it out on inside, as apparently the furnace ran all last winter with the cap resting on top of flue pipe and as so, it has pipe very very full of oil and grease like on inside, that is sure to also be on inside of furnace
he is worried that if opened up it might open a can of worms to something they no longer make parts for
its a oil furnace, and been running Kero in it due to above ground tank and cold temps here(Ne PA)
he recommend replacing whole furnace with a new unit
but I am iffy on this, as the roof on this place is in so so condition and worry about cutting oil old flue crown and pipe, to replace and being a leaking issue, took 10 yrs to get his one to finally stop leaking as is?
so would anyone know any place parts could be had for this unit, if needed, and if not, does anyone have any experience with electric furnace's
would one of them work without need to be vented like the oil one's?
thus then NOT having to cut open the roof here at all, and can then just block off the opening in current roof jack.vent
so any and all help is appreciated, as are any suggestions on a new electric furnace if you think they can be added here and again not need a new roof jack to use them
as well as how well do they even work in cold environments like where I am at?

User avatar
Posts: 5517
Joined: Wed Feb 28, 2007 8:01 pm
Location: Weedsport, NY

Sun Sep 16, 2018 8:19 am

It sounds like it's time to bite the bullet and upgrade. I would look at alternitive heating sources also.
We have a 91 with an original furnace that has maybe 3 seasons of use. We used a Monitor heater for years and switched to a Harmon pellet stove.
No matter what you do, the roof needs to be weather tight.

"If I can't fix it, I can screw it up so bad no one else can either."

Posts: 72
Joined: Mon May 23, 2011 5:59 pm

Sun Sep 16, 2018 1:46 pm

thanks the roof now is finally weather tight, and that is also why I do not want to have to add a new roof jack for a new furnace
took too many yrs to get it to not leak, don;t want to open another can of worms if I can help it, colder temps are here and it rains almost every day and has for the past 50 of the last 68 days
so wrong time of yr to be making a hole in roof .
furnace run flawless besides the chimney jack/pipe being bad?, scared to open furnace up and have anything get damaged and NOT be able to get replacement parts for it
what do you know about electric furnaces? as if I need to buy a new furnace I was thinking about them as I don't think they need to have a roof jack, , so NO hole needed to be cut in roof?
so any feed back on electric furnaces, do they work well, keep up with cold temps, and will they last ?? and how long will they last on average?

thanks again for the help and info!