New FWC hawk furnace not working in cold

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rustyshackleford55

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Hey everyone, not sure the model but its a 2018 FWC Hawk Atwood furnace.

I noticed that when the furnace has been running for several hours, in cold weather ( below 10 degrees ) that eventually the furnace stops firing the ignition.

I don't hear "click click click". The fan comes on for 10-20 seconds, and then goes off.

If I turn the furnace off for an hour or so, and retry, the furnace fires right up. So it seems like the furnace is in some sort of state that is preventing the ignition from firing.

Any ideas?
 
One of several things...

1. No propane to burner - for whatever reason, even intermittent

2. Open external access door and check that the aluminum tube does not have a bird's nest or other debris in it

3. T-Stat failed. Can pick one up at any RV supply store for ~$15. The T-Stat is in the compartment behind the external access door; behind the black foam.

4. Behind the external access door is the potted circuit board. If it fails the entire thing must be replaced. This happened to me on a trip and I had Amazon drop ship one to me on-the-road. Rather than point you to the one I bought, best to enter your Attwood furnace model into Amazon's search window to make sure you get the right unit.

My troubleshooting went as follows...
Propane gas - check
No debris in unit - check
Replaced T-stat - no help, unit still inoperable
Replaced potted circuit board - unit works fine

I have no idea what caused the board to fail. But 2 nights in sub-freezing temps in northern AZ, in the snow, was enough for us and I paid for overnight Amazon delivery.
 
rustyshackleford55 said:
Hey everyone, not sure the model but its a 2018 FWC Hawk Atwood furnace.

I noticed that when the furnace has been running for several hours, in cold weather ( below 10 degrees ) that eventually the furnace stops firing the ignition.

I don't hear "click click click". The fan comes on for 10-20 seconds, and then goes off.

If I turn the furnace off for an hour or so, and retry, the furnace fires right up. So it seems like the furnace is in some sort of state that is preventing the ignition from firing.

Any ideas?
Click to expand...
Just to add... it is a 2018 model, are you within the warranted period with FWC?

If so I would be contacting them for a solution also.
 
pvstoy said:
Just to add... it is a 2018 model, are you within the warranted period with FWC?

If so I would be contacting them for a solution also.
Click to expand...
Mine was under warranty as well when it failed.

If you read FWC's fine print, you are only covered by Atwood's warranty, no extra warranty from FWC.

And Atwood has a notorious reputation fulfilling warranty claims. My calls to them were nothing more then wasted time and frustration. Getting the furnace up and operating was paramount to my wife's happiness so I repaired the unit on my own dime as quickly as I could.

A northern AZ FWC dealer was unable to help, but, offered every tool I needed and didn't have. The local RV dealer carrying Atwood products had a 6 week backlog to simply troubleshoot the unit.

The unit is very simple in design. The problem can can almost always be traced to the T-Stat or potted circuit board.
 
This is a real reflection on the sad state of affairs in the RV industry and in particular QC and customer service. Unfortunately FWC has subscribed to this bogus sub-contracting of warranties.

If the alternator in my Tacoma has an issue, Toyota addresses it, not Denso, and they do promptly and give me a loaner vehicle while mine is in the shop. If the hard drive on my laptop is flakey, Apple doesn't send me to Samsung to fix it, they fix it in store or give me a new laptop. The idea that the components in your camper are warrantied by their manufacturers is passing the buck.

But back to the problem at hand - how is your battery? The ignitor draws a bit of current and if you have a battery that gets weak in the cold, it may be enough to trip the low voltage shutoff (if the furnace has one). Once the battery rests for a while it may come back enough to start another cycle.
 
Thanks for putting that in perspective. It is a real eye opener as what falls on the owner to do. I find that the middle man that is having the problem does all the work and keeps the ball rolling just to have something fixed or problem solved. A lot of hours you don't get paid for.

I did forget about low battery voltage.
 
Try checking your battery voltage when this happens. If after running for several hours the voltage may drop enough so the fan doesn't run fast enough to engage the sail switch.
 
When I first started researching truck campers I was astounded by the concept of paying $20-$40,000.00 for something and have the builder hand you a bunch of manuals so you could contact the maker of that particular product when you have issues.....really people?

This is only allowed because we the buyers allow it. If we refused to purchase under those restrictions the builders would have to acquiesce and do their damn job!
 
Good point about battery voltage.

But if you're running the house battery(ies) (other than LiFePO4) below 50% capacity, ~12.1V, you're killing your battery and vastly reducing its lifespan. You will be replacing the house battery every 12 months or perhaps sooner based on use and continual deep state of discharge.
 
Regarding FWC warranty, or lack thereof for installed components, I did not know that was the case until after I took delivery. I think most buyers are not aware of this because we didn't know to ask the question.

But, I wholeheartedly agree that if an installed component fails, one should be able to take the camper to any FWC dealer and get the component repaired or replaced if still under component manufacturer's warranty. Dealers should be carrying things like T-Stats and potted circuit boards for the furnace and perform the required maintenance for the owner.

But, current practice will not change until owners and prospective buyers demand change. After all, it will only diminish FWC's bottom line resulting in increased prices for buyers of new units.
 
Ours had a bad solder joint on the board.
Was difficult to get Suburban to help but was finally able to resolve the bad board issue.

Russ
 
I'll follow up here to all the comments:

1) FWC / Juniper overland has been good about fixing issues under warranty. I've had a few furnace issues and eventually Juniper just replaced the entire furnace free. The issues in the past was the furnace would fail, but would never work again. Typically the ignition switch failed. In this case, the furnace fails in the cold and prolonged usage, but works again after some rest (1 hour or so).

2) My batteries were showing 2/3 full per the factory analog controller. I have the two 12v batteries, from 2018.

3) Is it possible something is freezing up?
 
As Camelracer suggested, have the sail switch checked also.

If it works when the furnace is first started, fails after running for some time and works after cooling for a while, careful use of a heat gun to preheat should be doable. Same method could work for testing circuit board.

Search web for “Atwood rv furnace sail switch” & you will get lots of hits. Some may give useful info,
Good luck

Paul
 
I had a tank of propane that was filled down south give me similar problems. There was more butane in the propane mix and it wouldn't turn to a gas fast enough when it was cold. After it had recovered it would light again. After I replaced the tank with a Minnesota filled tank everything worked better. The stove burner, fridge burner and Water heater all had noticebly better flames. Hope this helps, Bigfoot Dave
 
Bigfoot Dave said:
I had a tank of propane that was filled down south give me similar problems. There was more butane in the propane mix and it wouldn't turn to a gas fast enough when it was cold. After it had recovered it would light again. After I replaced the tank with a Minnesota filled tank everything worked better. The stove burner, fridge burner and Water heater all had noticebly better flames. Hope this helps, Bigfoot Dave
Click to expand...
This is an interesting bit of information we should all be aware of. I was not. Thanks for adding to the discussion!
 
Furnace should work down to well below 12 VDC. It is normally very easy to hear fan running slowly due to low voltage. Suggest thermo cut-out that protects against over temperature is weak. Atwood has traditionally had a problem with the relay opening at too low a temperature. I used to replace them somewhat routinely exhibiting the same problem. It opens when it gets too hot and closes when it cools down. Then does the same thing when it gets hot again. Does the problem goes away when furnace run time is shorter?

While in business I always carried t-stats and boards for every appliance in stock. Many repair services and nearly all dealers do.
 
The fan sounded strong as usual, I just never heard the click click click. Next time, hopefully not, I'll try turning the truck on
 
rustyshackleford55 said:
The fan sounded strong as usual, I just never heard the click click click. Next time, hopefully not, I'll try turning the truck on
Click to expand...
The board turns the fan on which in turn closes the sail switch and runs through the high limit cut out to complete the circuit to the board telling the board it is okay to go to ignition. If both those switches are not closed the board will not go to ignition because it is being told either air flow is inadequate (the sail switch is called an "air prover") or if the cutout is open it is being told the furnace is running too hot. Can be for a variety of reasons.

If you are worried about voltage jump put a jump box on your camper battery.
 
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