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[GMCnet] New furnace [message #331530] Sun, 29 April 2018 22:18 Go to next message
Richard Denney is currently offline  Richard Denney   United States
Messages: 920
Registered: April 2010
Karma: 9
Senior Member
So, at Bean Station last year, we were...chilly. The furnace hasn’t worked
in several years, but I had put it off, because the heat strip in the roof
air has usually been enough to take the chill off and we don’t camp in the
winter. But we can’t pull that kind of power at Bean Station, and we didn’t
want to run the generator, so we were chilly.

Last week, between trips, I saw a Suburban NT30SP on eBay—same as the
furnace in the coach. It was new, but a scratch and dent special, having
been bent up a bit during shipping during a return from a previous
customer. Price was well under $300, which is pretty cheap for a new
furnace. I took the risk.

It arrived on Saturday. It was pretty beat up, and the igniter was broken,
but I was able to straighten everything pretty well. I decided I could
leave the existing sheet metal case in place, but even pulling the guts of
the old one exposed a previous mistake. I have replaced the end of the
kitchen cabinet within which the furnace is installed. And a PO had built
the cabinet around the furnace, so both of us had left no means of
extraction. I therefore had to cut a 13x13” hole in the end of the cabinet,
which allowed me to extract the guts of the old furnace.

And I found an issue with the old one. A wire going to the motor was
showing copper for an inch, as if the insulation had burned off. That was
the part of the wire running through the remains of a large and complex
mouse next. I swear it was an apartment complex. After vacuuming all that
up, I tried to prevent a future occurance. Stainless steel wool in the gaps
around the inlet and exhaust, 1/4” hardware cloth over all the case vents,
and more stainless steel wool around the wiring harness and all other
openings. Eventually, I’ll have the coach stuffed with steel wool.

The new furnace went in fairly smoothly. After getting the gas and wiring
harness connected, I tested it. Nothing. No fan, even after the expected
delay.

So, I starting troubleshooting the wiring, and eventually discovered that
the thermostat wiring has a discontinuity. It’s wired in series with the
sail switch and the limit switch, so the module never had the signal to
turn on. The old thermostat wire was typical 18-gauge solid-core wire
sandwiched between wall materials between the galley and the bathroom, and
I’ll bet some stress point fatigued the wire and it broke. PO’s—what are
you gonna do? So I fished a new pair of wires (16-ga stranded) down the
chute used by the plumbing vent stack and now everything works.

Of course, Bean Station will be warm and sunny an we won’t need the furnace
at all. But at least one more hidden mouse nest is now gone.

Rick “now I gotta figure how to cover the hole in the end of the counter”
Denney

My suspicion is that the old
--
Rick Denney
73 x-Glacier 230 "Jaws"
Off-list email to rick at rickdenney dot com
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Re: [GMCnet] New furnace [message #331534 is a reply to message #331530] Mon, 30 April 2018 07:06 Go to previous messageGo to next message
jhbridges is currently offline  jhbridges   United States
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
Senior Member
Rick -

Take a look in my coach, and I'll show you how to get the furnace out of the cabinet without cutting the side. You still cut, but it doesn't show. Courtesy of Miguel Mendez - I assume he installed the new furnace fr the PO. Stick Miller showed me the way to beat the cold at Bean Station when my heat pump decided it was too cool to work. An electric blanket is Your Friend. 35 bucks at WalMart/


--johnny


Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons. Braselton, Ga. I forgive them all, save those who hurt the dogs. They must answer to me in hell
Re: [GMCnet] New furnace [message #331538 is a reply to message #331534] Mon, 30 April 2018 07:33 Go to previous messageGo to next message
Richard Denney is currently offline  Richard Denney   United States
Messages: 920
Registered: April 2010
Karma: 9
Senior Member
Johnny, how to you keep from tripping the camp breaker if we all use that
large-current AC stuff? But we weren’t cold under the covers—it was when we
eventually had to emerge that it became noticeably chilly.

The opening in the side of the cabinet is now already there. :) I could
have set up a removable side, but a nicely finished access hatch works just
as well and it’s a lot easier. For the moment, I covered the opening with a
sheet of birch-faced 1/4” plywood.

Rick “new leveling valve and supervised ride height setting are my Bean
Station projects” Denney



On Mon, Apr 30, 2018 at 8:08 AM Johnny Bridges via Gmclist <
gmclist@list.gmcnet.org> wrote:

> Rick -
>
> Take a look in my coach, and I'll show you how to get the furnace out of
> the cabinet without cutting the side. You still cut, but it doesn't show.
> Courtesy of Miguel Mendez - I assume he installed the new furnace fr the
> PO. Stick Miller showed me the way to beat the cold at Bean Station when my
> heat pump decided it was too cool to work. An electric blanket is Your
> Friend. 35 bucks at WalMart/
>
>
> --johnny
> --
> 76 26' Eleganza(?) with beaucoup mods and add - ons.
> Braselton, Ga.
> "I forgive them all, save those who hurt the dogs. They must answer to me
> in hell" - ol Andy, paraphrased
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Rick Denney
73 x-Glacier 230 "Jaws"
Off-list email to rick at rickdenney dot com
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Re: [GMCnet] New furnace [message #331541 is a reply to message #331530] Mon, 30 April 2018 08:28 Go to previous message
jhbridges is currently offline  jhbridges   United States
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
Senior Member
The reason I use the electric blanket is, it's not large current. Draws just under 2 amps on the highest setting, which I don't use. Your 12V coach power supply draws more if you've a couple of lights on and the battery charger going. Have a look:

http://www.electricblanketinstitute.com/features-benefits/actual-cost-to-run.html.

If I run my furnace, it will draw more power for the fan than this - off the 12V supply.


--johnny


Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons. Braselton, Ga. I forgive them all, save those who hurt the dogs. They must answer to me in hell
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