Heat, 2007 Journey 39K

[jaym368]

Just a question about using the propane heater.  We've had this motor home for almost 2 years and like it.  The only problem is the gas heater doesn't seem to keep the unit warm.  An example is, I went over to the motor home the other day to finish getting it ready for our trip to FL.  We stay south till April.  The temp inside was 35 degrees.  I started the gen and set the gas heat for 65.  An hour later it was only 44. There is heat coming from the floor vents but not enough to brag about. We had a 2002, other brand, 39 foot diesel pusher and it wasn't nearly as insulated as this one, but we were warm.
  Didn't know if is just the nature of the beast or is there something else going on.

 

[afchap]

Doesn't sound right to me. Mine certainly does better. I qould check for good air flow at each floor vent. Poor flow and/not warm air would indicate possible problems.  One thing to check just to be sure is the return air grill. Ours is under a couch and the entire area under the couch was still was totally covered with the carpet protector plastic after delivery ...little air in means little air out.

 

[John Hilley]

Maybe your ducting has come loose from the furnace plenum. What about the filter?

 

[Gary RV_Wizard]

Poor air flow is typically either a kinked or crushed flexible hose in the heat distribution system or blocked air intake on the furnace itself (the air return to the furnace). If you have rigid metal tubing for the heat distribution ducts, check for blockage like maybe a piece of insulation fell in - or even a "critter" nest. If the intake has a filter, make sure it isn't plugged with dust.

Do you notice the furnace burner cycling on/off even though the fan keeps running? If an insufficient amount of air flows through the ducts, the furnace overheats and shuts the burner down for awhile, leaving the fan running to cool it down. Then it automatically restarts the burner. This is called "cycling on the High Limit switch".

 

[jaym368]

Thanks for the replies.  I'll go over to the motor home tomorrow and check the duct work.
Gary, It don't think it's cycling, but I'll go out  to the exhaust and check. It's hard for me to hear it when I'm inside.
I'll post tomorrow after I check

Thanks again

 

[John Canfield]

.. If the intake has a filter, make sure it isn't plugged with dust...

Winnebago doesn't use filters on propane furnaces.  Good ideas from everybody - I have nothing else to add.

 

[Old Snipe]

I have the exact same year and model MH and I agree the front heat ducts do have a weak flow.  However, what I do is crank the heat up high, to about 75-80 so the furnace runs longer and hotter.  After about 1/2 hour, I have to cut the t-stat setting down because it gets really warm.  If the temps are above 40 degrees, use the electric heat pump, again set high.  It will blow cool air for the first 3-4 minutes but then warm up and heat the interior nicely.

The reason you have to set the temps higher is the t-stat is about five feet high off the floor and that is the level it senses the heat.  The floor will be 10-20 degrees colder that the t-stat level. 

Best Regards!

 

[megammon]

I had the same problem in my class C, I went through everything and I had some plugged ducts. A mouse or bird made a nest in one of the ducts I pulled out a small garbage bag of nesting material. Now the system works great.

 

[Mavarick]

Yea, something is definitely wrong there. I started my furnace yesterday when I pulled it out and it was about 35 inside. Within 45 minutes I was at 60 inside and it was comfortable for how I was dressed (working outside). Also, that hot air exhaust should be so hot you can?t hardly keep a bare hand over it for too long.

 

[jaym368]

Thanks for all the info. I went to the motor home today and started the gas heat after spending some time trying to get the door open. It was frozen shut with a layer of ice on it.
    It was 17 degrees inside, and outside wasn't much warmer.  I couldn't get the motor or the gen started.  Luckily its stored at a nearby campground in a site that has electricity.  I hooked up the shore power and turned on the engine heater. I'll go back tomorrow and start it. 
    I was there for over two hours and the inside temp went up to 37 degrees.  I went underneath, using a large piece of cardboard and nothing is accessible.  It looks like the duct work is in between a double  floor, also I couldn't find the air intake for the furnace inside or outside. I wonder if having the slides in makes a difference.
      Gary, the furnace stays on, it doesn't cut out.
    The motor home was iced up pretty good.  I spent most of those 2+ hours shoveling snow and ice off the roof and from around the outside.
    I think it's too cold for me to check further into the problem until we get south. It's probably a critter nest somewhere.
    We're leaving the 12Th and it usually takes us two days to get far enough south to be able to use the electric heat.  We have one space heater and I'm going to buy another one before we leave.
    Thanks again for all the advice.

 

[Gary RV_Wizard]

Your furnace has two separate air circulations, driven by two fans on a single motor shaft. The inside air is drawn into the furnace, heated, and sent out through the inside ducts. Combustion air for the burner comes from the  outside via an external inlet and the exhaust fumes are returned outside. The air circulation you are concerned with is strictly inside, so find the ports inside that bring interior air to the furnace, It, and the interio rair outlet ducts, should be readily visible with the covers off. No need to lay outside in the snow.

 

[afchap]

To find the inside air return grill, turn on the lp furnace and follow the blower noise. Normally it is immediately above or very close to where the furnace is. So find the two small circular ports outside where you feel the exhausted heat when it is running, then go inside and look in that area. My main furnace return is a grill in the floor under a couch. My bedroom return is a small vertical grill under the washer/dryer. Some are under a cabinet, etc. You should be able to follow the blower noise to the intake.

 

[Ernie n Tara]

In my Journey, the return is outside the bathroom wall toward the front. It is behind the end wall of the single LR slide. It likely would be blocked with the slide in and there is a small shelf there where it would be very easy for something to fall and block the return. Might check there in yours.

Ernie

 

[Tin man]

Not my forte, but my AC was not working as it should, andi replaced the filter (in the night stand) next to bed.  The fan worked much better. Do not know if they are related...

My Two cents and I don't thinknitviscworth a penny.  Happy New Year.....

I run the gen, and use the electric heat when I leave for Florida..

 

[SVTotem]

Jay,
You might invest in an infrared thermometer if you do not already have one. It will allow you to easily check temperature differences along  the ducting or find hot spots where there are air leaks. With the temperatures you are experiencing there should be quite a noticeable difference in temps if you are heating and area through a leak in the ducting.

 

[jaym368]

Thanks again for all the info.  I found the air return vent. It is under the vanity in the bedroom. I had to pry up the bottom shelf in the cabinet below the sink. The back wall of the cabinet is approximately 3 inches away from the bedroom wall leaving an area where the sink drain and water lines are located.  The problem is the false wall doesn't go high enough to stop articles stored on the top shelf from falling down behind and then blocking the intake.  I found a hand towel on top of  part of the vent. The heat is much better now. I'm posting some pictures. Tried last night to post but no success.  Thanks again. I've got to send three separate posts, it won't let me send multiple pics.

 

[cwhtrains]

From looking at the Winnebago drawings, it would appear that the intake to the propane furnace (not the heat pump A/C unit located in the rear of the passenger side of the motorhome) is located underneath the dresser in the bedroom area (maybe five feet from rear of motorhome) on the passenger side of the motorhome. Typically, the furnace intake would then draw air from the bedroom through a vent/grate along the bottom on the dresser. (On my 2006 Journey 36G the intake vent is located out in the open space on the floor, so I can not put an area rug in that space.) If something has fallen out of the a dresser drawer and down on top of that furnace intake on the floor that is located underneath the drawer, then just about all the air flow would be blocked. It may be possible that someone left the clear plastic flooring protector in place as well. Pull all of the bottom drawers all the way out and see if anything is blocking furnace intake itself. Turn furnace on and if you are getting good air draw into furnace at the intake point, then something is wrong from the output side of furnace. If so, then you will need to go through the ducting piping and the vents that are on the floor. If those vents on the floor are covered with area carpets, then that will restrict heating air flow and heat circulation, or there could be some debris that is blocking the air flow through the vents. If you are getting good air flow into furnace and out through the floor ductwork, then the problem is probably within furnace itself.

Let us know what you find out, as doubt one of us will have a similar problem at some point as well.

 

[cwhtrains]

Looks like you found it while I was typing. Great result!

In looking at the photo, how does the furnace intake get air flow if the cabinet doors are shut? Is there a path for air to get to the furnace intake when the cabinet doors are closed?

 

[jaym368]

Pic 2

 

[jaym368]

pic 3