I’m not certain about the verification requirement. Aero Teardrops offers Propex as an optionlarryqp said:
Dometic furnace sail switch rehash/update
- Thread starter ri-f
- Start date
ri-f
Senior Member
Wallowa said:
It goes by model number and specific serial number (year is not specific enough). Call Dometic tech support for confirmation of any updates/u[pgrades to your specfic unit and to learn which switch model number is correct for your unit.
Mthomas
Senior Member
Personally, I am having good luck with the installed Dometic, knock on wood. Successful heating from sea level to 10,500 ft so far. My only failure occurred once when I opened the valve too fast after changing a bottle and the safety in the tank kicked in. I do an annual cleaning of the sail switch and am prepared to remove the vent cover if needed.Vic Harder said:
I have looked at the above heaters for eventual replacement. With a diesel truck it makes a lot of sense if the dometic kicks the bucket.
ri-f
Senior Member
+1 on that. I've had an almost identical experience with my Dometic, including the 'opening the valve too quickly' scenario. But other than that one time when I was connecting a new propane bottle, it's been seemless from sea level to 10,000 ft, as well. There are at least a handful of scenarios that could trigger an ignition failure or staying lit failure and the sail switch is just one of those examples.I used to run a Refleks gravity-fed, diesel-drip heater on a boat, which truly was a bulletproof system requiring no electrical components. It won't work on a pop up camper because of the long stove pipe that is required. Next best solution is to install a small, portable backup heater (like a Wave, for instance) in case your primary one fails at exactly the wrong time. And sooner or later, if it has a circuit board, switches, ignitors, and moving parts, it will probably fail at the exact wrong time. The argument with the Dometic, at least for some people, is that it didn't take very long for the failure to occur on a new unit, which is what is unfortunate.Mthomas said:
MrDoughnuts
New Member
- Joined
- Aug 19, 2021
- Messages
- 3
Just received my Fleet last week. Took it out over the weekend and early this week. Did some camping. Furnace didn't work so well.
Today I tried to do some troubleshooting in the parking lot. Furnace seems to work fine with the front face plate off but when I put it back on it no longer kicks out heat. I was 0/4 with the face plate on. 4/4 with it off. Voltage seems to be fine.. above 13.3V. Anyone have experience with this issue?
Thanks in advance.
Today I tried to do some troubleshooting in the parking lot. Furnace seems to work fine with the front face plate off but when I put it back on it no longer kicks out heat. I was 0/4 with the face plate on. 4/4 with it off. Voltage seems to be fine.. above 13.3V. Anyone have experience with this issue?
Thanks in advance.
heinphoto
Senior Member
Removing the short length of ducting between the furnace outlet and the front panel/grate has become a common fix for heater problems - particularly when camped at altitude. My understanding is that depending on the alignment, the ducting can cause enough flow restriction to prevent the sail switch from activating and allowing the heater to start. Removing the ducting is FWCs solution at the moment.MrDoughnuts said:
MrDoughnuts
New Member
- Joined
- Aug 19, 2021
- Messages
- 3
Great! Thanks for the reply. I'll try that.heinphoto said:
Charlie
Advanced Member
Yep, just removing the restrictive corrugated dryer hose has 100% reliably fixed the problem for me. And I think the heater works just as well without it.heinphoto said:
My guess is that some units don’t spin the blower (which activates the sail switch) as fast as others, and so there is not enough airflow to activate the switch. Could be the voltage of your batteries, or a marginal motor, or fairies.
I replaced the sail switch with a new one, but clearly there was no difference between the old and new ones, and they both seemed to take the same amount of pressure on the sail to activate. They are really garden variety micro switches, used in millions of consumer devices. There is nothing special about them. I thought about redesigning the sail itself so that it would catch more air, but there are more compelling mods that I need to make.
I also wonder if the particular orientation of the furnace installation in the FWC is an issue? The switch uses gravity to return it to one position; I can’t remember which.
DanoT
Senior Member
Propane furnaces use a combination of outside air as well as cabin air for combustion.
Not enough cabin air was an initial problem with my Phoenix camper (furnace kept shutting off); fixed by providing a vent in the door of the cabinet that is beside the furnace allowing more cabin air to get to the furnace.
FWC might be having a similar not enough cabin air getting to the furnace problem.
Not enough cabin air was an initial problem with my Phoenix camper (furnace kept shutting off); fixed by providing a vent in the door of the cabinet that is beside the furnace allowing more cabin air to get to the furnace.
FWC might be having a similar not enough cabin air getting to the furnace problem.
DanoT said:
Lost me there....not enough cabin air for furnace in a FWC? Thought since furnace is on outside wall and vented to outside that cabin air did not enter into the equation...but honestly don't have an image of how the furnace and sail switch function...oh, my Hawk has the flexible section just behind the face plate in the camper...no problems so far with lots of furnace use...
Charlie
Advanced Member
Agree, I don’t believe that any cabin air is used for combustion. There is a very tight intake port and exhaust port on the outside of the camper. I’ve had the covers off on both the inside and outside of the furnace, and their is nothing I see that allows airflow between the two. Well, the hole that the sail switch fits into might allow a tiny bit of leakage to the outside, but it’s not connected to the combustion side.Wallowa said:
I wanted to chime and mention my issues with the heater on my '21 Hawk Shell. At about 10,000ft I was not able to get the heater to work. It would run for a short time and then shut off. After reading about the restriction issues, thanks btw, I took the center diffuser off. It worked perfectly after that.
On mine the grill/round diffuser is off center of the furnace about 3/4". I assume this is creating some of the restriction. I plan on removing the flexible duct and giving that a try. Has anybody tried the high temperature aluminum foil tape? I may try that on the one side to direct a little more to the diffuser.
On mine the grill/round diffuser is off center of the furnace about 3/4". I assume this is creating some of the restriction. I plan on removing the flexible duct and giving that a try. Has anybody tried the high temperature aluminum foil tape? I may try that on the one side to direct a little more to the diffuser.
heinphoto
Senior Member
Even though the combustion and cabin zones are separate, I think there is still only one blower/fan. My understanding is that this particular problem is associated with newer versions of the furnace and mostly in "edge cases" like high altitude or low battery. I also recall reading that the newer version of the furnace was designed to have lower power requirements for off-grid camping. So, my speculation is that it has a less powerful fan that is more sensitive to flow restrictions/back pressure on either "side" of the furnace. Removing the ducting has definitely solved the problem for a number of people and is what FWC has been recommending in these cases. With that said, we haven't experienced problems (yet) with the furnace in our 2020 Grandby even though we have camped at ~10,000' on several occasions. So, it may be caused by a combination of factors - altitude/battery voltage/outlet flow restriction/individual state and tolerance of the blower and sail switch/etc.
FWIW,
-Scott
FWIW,
-Scott
A thought....uneducated one...the exterior heater vent on my furnace in the Hawk is pretty much open to anything out and about of the camper....I had a wasp nest inside such a vent on our home and the burner could not be cleared before ignition so it would not ignite..I put a mesh screen cone [from an RV supplier] on the exhaust port on the Hawk to keep out unwanted critters or debris....could this diminish the flow of the furnace and be a, or the, source of the issues folks are having?
I can't find a diagram of how the Dometic furnace is constructed or installed in the Hawk...can anyone post a photo or better yet a drawing of the furnace as installed in a FWC...
Just a WAG and the assumption that it might not be a single variable but several small issues that ultimately cause the problems folks are having...
Phil
I can't find a diagram of how the Dometic furnace is constructed or installed in the Hawk...can anyone post a photo or better yet a drawing of the furnace as installed in a FWC...
Just a WAG and the assumption that it might not be a single variable but several small issues that ultimately cause the problems folks are having...
Phil
J D
Member
Resurrection day for this thread!
Well, after having more and recent issues with the heater in my Granby I went online looking for info. That led me to WTW where I've found plenty help in the past. This time it was helpful but with some discrepancies.
After reading this thread I took OP's advice and called Dometic with model and serial #'s. My model is same as OP's (DFSAD12111). I not only called once but twice. First call was to request part number for sail switch for my heater where I was told 33082 was the correct number. Second call (after re reading OP's first post on this thread) was to verify. Indeed, 33082 is the correct part number!
I was told 33082 replaced 33081; 33082 comes with a new mounting block that has been re-designed and to NOT re-use the old mounting block from the old switch.
I know this is exact counter to what OP noted.
Well, after having more and recent issues with the heater in my Granby I went online looking for info. That led me to WTW where I've found plenty help in the past. This time it was helpful but with some discrepancies.
After reading this thread I took OP's advice and called Dometic with model and serial #'s. My model is same as OP's (DFSAD12111). I not only called once but twice. First call was to request part number for sail switch for my heater where I was told 33082 was the correct number. Second call (after re reading OP's first post on this thread) was to verify. Indeed, 33082 is the correct part number!
I was told 33082 replaced 33081; 33082 comes with a new mounting block that has been re-designed and to NOT re-use the old mounting block from the old switch.
I know this is exact counter to what OP noted.
ri-f
Senior Member
JD - that's interesting. And you're right regarding what I said in my post:J D said:
"The original OEM sail switch model number for mine was #33082 (which is what FWC says they keep in stock for replacements. repairs, etc). But Dometic says that those were problematic switches and they recommend not using those, but instead using model #33081, because it was redesigned to work correctly."
It's possible that you got someone, at Dometic, that isn't well informed. Or, I got someone who wasn't informed. But they did emphasize, strongly, that #33082 was faulty and had been redesigned - the new number being #33081. I still believe that to be the correct answer, but I can't say for sure, as I never installed it. My original sail switch had not failed, I was simply ordering a spare just in case it did fail.
Best,
Rich
pvstoy
Senior Member
Rich,
Interesting.?. #82 comes after #81. If I was making parts then #82 would be a improvement over #81 thus replacing the lower numbered part.
So the stock current #82 was not working out and decided to go back to a lower numbered part #81.??
Interesting.?. #82 comes after #81. If I was making parts then #82 would be a improvement over #81 thus replacing the lower numbered part.
So the stock current #82 was not working out and decided to go back to a lower numbered part #81.??
It is counter-intuitive to redesign anything and not give it the next larger numerical designator rather than a lower number...
Why was 33082 revised and then re-numbered as an improved switch to lower numbered 33081? And would FWC camper stock and use the unimproved model? Seems backward, but I could be wrong.
Just saw #38 post ....same question.
Why was 33082 revised and then re-numbered as an improved switch to lower numbered 33081? And would FWC camper stock and use the unimproved model? Seems backward, but I could be wrong.
Just saw #38 post ....same question.
ri-f
Senior Member
Actually, I think that is exactly what they did. It wasn't really a redesign or upgrade of the 33082 as much as a realization that the existing 33081, designed for a different model/serial number did a better job with regards to air flow across the surface of the sail. The 33081 sail switch didn't fit the base of the 33082, so you have to buy the more efficient 33081 sail switch and the base that comes with it (ti.e. you need to buy the complete kit), which you can buy on Amazon for $29.99: https://www.amazon.com/DOMETIC-33081-SAIL-SWITCH-SMALL/dp/B085MMHB65pvstoy said:
Not saying any of this makes a lot of sense...just what they did, or at least what Dometic told me they did, back in May of 2021.
Rich
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