Propane Furnace Exhaust Fumes Inside New Coach

[Paul James]

@ Jim & Linda.. thanks, good to know

[rvtamer]

I have to agree with Kirk and Yarome on this one. I have been installing new furnaces for 45 years and this is quite common. Its not exhaust gas it is oils and dust and manufacturing residues that are burning off of the heat exchanger. This IS common and will lessen fairly quickly.

 

Paul James,

 

I have done a lot of PDI's on all kinds of RV's over the years and can hopefully answer your question.

 

Part of a dealers PDI is to have a RV tech check the furnace operation.

 

During that first start up and burn , a protective coating that was applied to the heat exchanger by the manufacturer of the furnace , is burned off . This will cause smoke to sometimes enter the INSIDE of the RV and it will not smell good.

This initial burn of the furnace should last from 30-45 minutes to get the furnace hot enough to burn the coating complexly off. Sometimes it requires even more time.

 

If the burn time of the furnace was shortened by the service tech , an incomplete burn off will occur and the customer will experience a partial burn off (smoke & smell inside the RV ) when he/she turns it on at a later time. This might even occur a couple of times by the RV owner until the furnace has been run long enough to do a complete burn off.

 

Another poster said that this kind of smoke should not be present inside the RV anytime . They indicated it could be a cracked heat exchanger that could be leaking fumes.

 

Of course under any different times I could most likely agree with them , but not during the initial firing of the furnace of a new RV or during an initial fire up of a replacement furnace.

 

You see some of the protective coating is applied to the OUTSIDE of the heat exchanger which sets INSIDE the interior of the RV. When this coating gets hot from the burn, it (smoke ) will enter the INSIDE of the RV even though the heat exchanger is a sealed part of the furnace .

 

If after a proper fire up and burn off of the furnace was done and it continues to smoke inside, then you have a different and possibly deadly situation .

 

Paul, see if the dealer will give you a copy of the PDI by the service tech as part of the purchase. The PDI should document the testing of the furnace and the testing of the LP system ( including a leak drop test ). That would give you some peace of mind that the correct tests were done.

 

I hope this helps........tim

[Kirk W]

I hope this helps........tim

Tim makes his living repairing RVs and has done so for a long time.

[Paul James]

Thanks Tim for that thorough explanation, your post combined with others in this thread has made me feel better about my purchase.

[Paul James]

@ Mntom Tom.. I'd say the smoke looked sort of lightr grayish, it wasn't a thick smoke though; and I've got a pretty good nose and really couldn't smell anything. There was definitely no electrical or wood burning smell, so yeah, no strong odor of any kind.

[57becky]

This is copied and pasted from our very generic owner's manual from Keystone regarding furnaces. Ours did smoke some when we first started it, but as has been discussed, very little smoke, but enough to set off the smoke detector:

 

Furnace
The furnace is a propane gas appliance that requires 12 volt power to electronically light. New furnaces sometimes
emit smoke and an odor during the first 5 - 10 minutes of initial use due to paint burning off the heating chamber.
Do not mistake this for a malfunctioning furnace. Follow the suggestions in Chapter 3 regarding maintaining
Indoor Air Quality if this occurs. Please refer to the manufacturer instructions supplied with the unit for care and
operation. Please refer to the manufacturer instructions supplied with the unit for care and operation and/or www.
atwoodmobile.com or www.rvcomfort.com.

[Paul James]

Ok Tom thanks, that's what I'll do. Was pretty certain that's what the cause was, but good to have lots of corroboration. Thanks again.

 

Becky.. the smoke detector didn't go off because the battery was in backwards, intentionally I'm sure. Don't know if the propane detector is hardwired but that didn't go off either, but if it was oil burning off the unit it wouldn't. Thanks for printing that out.

[Yarome]

...open a couple of windows, crank up the heat, and let it cook.

 

X2.

 

Also be aware that the oven will need a bit of a burn off before first use as well. I know most dealers don't like to do that before a sale is completely finalized because it 'can' cause heat discoloration on some of the internals/racks/burner tubes. Folks looking to buy new don't like to see an oven that's obviously been "used" even though it was just part of a systems check.

 

Just a heads up since there may be some respiratory concerns.

[Paul James]

@ Yarome.. Yes, hadn't thought of that, I'll be sure to have them do that, don't want the same thing happening with the oven, it could well give me problems. Thanks again.