forced air furnace and power

[fuzzymarindave]

I suffered several years with intermittent heater problems, failure to fire until I removed the foil duct hose and cut out about 6 inches of excessive hose. The air from the hose now has a more direct path through the vent rather than making a slight turn. This simple task completely eliminated my problem. No more sleepless nights wondering if the heater is going to work.

Good idea. More direct path for air and maybe also stretched out the duct corrugations making even smoother airflow.

 

[craig333]

Something isn't right if your S.O.C. is 20% in the morning. I'll run my heater all night and not go below 85% S.O.C. and rarely see under 12.8 volts. My guess would be they aren't real deep cycle batteries and or they aren't happy with the charging conditions they see.

 

[pvstoy]

and my battery was down 20% by morning.

Craig I might read that as it dropped 20% to a morning value of 80% battery left. Though I just started reading recently......

 

[wicked1]

Craig I might read that as it dropped 20% to a morning value of 80% battery left. Though I just started reading recently......

Correct, 80% remaining. I could be falling back asleep w/ it running w/out realizing it, so it could be on longer than I think.. I'll get a current reading while it's running tomorrow while I'm cleaning up the camper.

 

[craig333]

Yeah, I could have had a senior moment there Is reading misconprehension a word?

 

[wicked1]

I'm from the midwest, so may not string my words together in the same way normal people do, heh...

And yeah, as others have said, power draw is right around 3 amps. Guess if you fall asleep w/ it running for hours, that adds up.

(My thermostat is not good, so I have it set up pretty high, and usually just manually control it when I need it.. Otherwise.. Today for example, I went out to heat up my camper.. It's got to be 60 degrees in there for at least 1/2 hour, but my thermostat still says it's 20 degrees! I have no idea what thermal mass needs to warm up before it finally is correct.. but it must be huge. I've even looked at the circuit board, and am almost positive I know which component is the thermal resistor.. and it's just hanging there in the air like any other thermostat.. No idea why it's so slow to react to the temp changes.)

 

[UmkaAndHawk]

I, too, had to make adjustments to the ducting to get sufficient airflow, in my case *at altitude!* Furnace would not start at altitudes around 9000 and above. Anything that took off back pressure on the single fan of the dometic furnace got it working. I wound up removing the louvers and replacing with a simple metal mesh because I didn't love the idea of removing the metal ducting entirely (even though the torturous path it goes through is clearly a design problem (there's absolutely zero reason the duct isn't located near to the furnace output...FWC could simply design/buy a duct with the opening closer!)

I've met other FWC owners on the road who appeared to share the same issue.

The other trick we used is a low temp thermostat so that, at night, we can leave the furnace on, but keep the camper at ~45° instead of ~60°F. This reduces cycling, but not as much as I might have hoped. Together, I can confirm we get about three nights of battery life with two AGM batteries, and little other use (phones, iPads, LEDs, that's it.)

Good luck, stay warm out there!

 

[DarinH]

I’ll jump on the bandwagon with that suggest removing the vent hose. The first cold night I tried to run my heater in my ‘21 Grandby, it wouldn’t stay lit running off a fully charged battery (twin 6v AGMs), but it would stay lit if I was idling the truck. Removing the vent hose did the trick and I haven’t had a problem with it since.

I’m annoyed as h*** that FWC keeps putting those POS temperamental furnaces in new campers, when there are other options out the that work like they’re supposed to.

 

[craig333]

In FWCs defense, my guess is they bought a couple thousand to get a discount before they realized there was a problem. I'm sure they're not happy with the issues.

 

[DarinH]

In FWCs defense, my guess is they bought a couple thousand to get a discount before they realized there was a problem. I'm sure they're not happy with the issues.

… does not justify putting a faulty product in their campers, because they got a quantity discount IMO (if that actually is the reason. We can only speculate since they won’t tell us). I couldn’t get anyone at FWC to help with my issue, and the video on their youtube channel didn’t work for me. I finally got the solution from the guy that installed my camper at the Bozeman dealership.

 

[AWG_Pics]

I replaced the FWC OEM thermostat with this Honeywell: https://www.amazon.com/gp/product/B002Z7EBCE/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Much more responsive and no problems at all. (Except when I forgot to turn the on switch on the side of the thermostat to 'on'.)

 

[Outnabout]

I replaced the FWC OEM thermostat with this Honeywell: https://www.amazon.com/gp/product/B002Z7EBCE/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Much more responsive and no problems at all. (Except when I forgot to turn the on switch on the side of the thermostat to 'on'.)

Just a matter of charging out wire for wire?

 

[AWG_Pics]

Just a matter of charging out wire for wire?

Yes -- pretty simple. I know nothing about electrical stuff and managed it in about 20 minutes, including 10 minutes of obsessing over the installation notes.

 

[Outnabout]

Yes -- pretty simple. I know nothing about electrical stuff and managed it in about 20 minutes, including 10 minutes of obsessing over the installation notes.

Thanks. I do the same. [emoji106]

 

[pvstoy]

replaced with same Honeywell.

What I did because you can not tell what degree setting you are placing the arm, I put a sharpie mark in the middle of the lever arm. Slide it all the way to the left and place a line under the lever sharpie line on the white body. do the same all the way to the left.

Take a thin ruler and place it under the lever. Make 35 mark at zero scale. Note the measurement at the 85 degree mark. Then it is just placing scaling marks at 45, 55, 65 and 75. I wrote on the white body at the lever arm the numbers ( 35,45, 55, 65, 75 & 85 )



If you don't do this then you are just guessing trying to line up your eye.

 

[blitzkrieg3002]

I gave up messing with my furnace, I was either too hot or too cold. I ditched the unit entirely and installed a Chinese Diesel Heater off ebay for $115. works pretty good and has a pretty low draw on the battery. I installed it in my propane bottle location on a swift shell model and pulled the furnace out and use that furnace area for storage. the CDH is pretty solid so far i'm impressed for the price. I've ran it multiple times at temps ranging from 1F-20F outside and it's worked out well. In temps above freezing you just can idle it and it sips diesel and power at less than 1 amp. below freezing you kinda gotta crank it up depending how warm you want it inside.

If anyone is looking for a furnace out of a 2015 swift shell for cheap hit me up.