Long running furnace & wheres the sensor

[2 DA WDS]

This weekend was our first campout with our current MS RE3 where the temperature got in the low 30s. I started out using the heat pump and discovered that apparently when it gets too cold it automatically switches over to the furnace. No big deal, kind of impressive. But, the furnace would run for quite a while then shut off for a minute or less then start up again and run for quite a while and then shut off for a minute and so forth. With all the insulation I am supposed to have I didnt think this was operating correctly but it did maintain a set temperature.
Is this the experience others have had in cold weather. When I had my Cardinal 5er the furnace didn't run nearly that often.
Also, I went looking for the temperature sensor in the lower level. I see the one in the bedroom under the cabinet above the window but for the life of me could not find one in the lower level. This is an 05 RE3 #1646. My other MS was an 05 RE3 #1850 and the sensor was under the cabinet to the left of the television. Can anyone tell me where the sensor is in this one?
Help me out here if you can.

[rverdlm]

First, I'm curious why your '06 has a lower number than your '05? The furnace issue does not seem normal to me. How is the air flow from the ducts? Is there any off time or does it just mostly run the whole time it is cold? Is the air coming from the ducts quite warm or just tepid? Have you checked the air coming from the outside exhaust? It should be to hot to hold your hand in for more than a moment. There are all kinds of protection (safety) sensor in the furnace and it seems like one of them is shutting the furnace (flame) down. It could also be low gas pressure. Try lighting the stove while the furnace is running. I had a furnace problem a while back (can't remember the symptoms) and when I tried to light the stove while the furnace was running the stove flame was almost non-existent. The problem turned out to be that liquid propane had gotten into the top tank valve (from my tipping it when putting it up onto the platform) and I was getting almost no gas to the furnace. The solution to that was for me to bled gas from the tank by loosening the screw on (green hand one) fitting from the tank. If you do it carefully and hold it in just the right position you can hear it escape. After doing this a couple of times everything work right. Now I'm very careful to keep the tanks as near vertical as possible. When it's in the 20's our furnace runs less than half time. It runs a while then shuts off for a somewhat longer time. I have not actually put a timer to it, but the off time is enough longer that it's obvious. Hope this helps.

[2 DA WDS]

Thanks for pointing out the '06', it was a typo. It is an 05. I'll wait for some cold weather again and go check the things you mentioned.

[Stripit]

The living room sensor in our '04 is the thermostat itself.

[rdunk]

On our 05 RE3, the temp sensor for the kitchen/living area is also on the bottom of the cabinet above the rear desk.

I guess it could be that the factory might have just failed to install the rear temp sensor?? Hope you find it!

[Gemstone]

I found that major air leaks in our unit were contributing to high energy useage, both heat and air conditioning. I stuffed the floor gap along the kitchen slide with a dense foam rubber, my utility bill went way down, and the units worked more efficiently. I now stuff any gap I can find with foam...just gotta remember to take them out when it's time to move!

Regards
Gemstone

[Motor31]

Check for notches cut into the seal for the bottom of the kitchen slide. Instead of using something to prevent the slide seal from being caught in the roller and keeping the seal intact, MS cut notches in it. This allows free flow critter, dirt, light and air circulation through the bottom of the slide in at least 3 places. I end up stuffing mine with rags at this time to stop this "feature". I'll graft on some additional seal material to close the "feature" in November or December when we are static for a couple months.

[rverdlm]

I think Stacy has it right. Your sensor is in the thermostat. Putting a separate sensor in the living room was a '05 running change. I remember when we did our tour while our unit was on the line this was mentioned as something relatively new.

[2 DA WDS]

The living room sensor in our '04 is the thermostat itself.
Is your thermostat mounted on the wall across from the shower?

[Stripit]

The living room sensor in our '04 is the thermostat itself.
Is your thermostat mounted on the wall across from the shower?

Yep. We figured it out by running bedroom a/c colder than living a/c with door between rooms closed. Living a/c shut off when bedroom temp reached arctic, but living room was still warm. We thought it was broke :o Remedy was to make sure bedroom isn't colder than desired temp in living room.

[bstark]

Another item to consider: the right angle sheet metal fitting that connects the plastic round ducting to the duct for the bedroom has fallen off a number of units and simply allows the majority of airflow from the rear of the furnace to heat your service area in the basement

[igotjam]

bstark is right. Happened to mine and another one I met.

[hitchup]

bstark is right. Happened to mine and another one I met.

Ditto here. We just retaped ours this week. It finally got cold enough in MD to use the furnace & no air was coming through the bedroom vents.

The Mobile Tech guy who serviced our furnace said it should have been nailed in. But David just retaped it for now.

[Huck]

the furnace would run for quite a while then shut off for a minute or less then start up again and run for quite a while and then shut off for a minute and so forth. With all the insulation I am supposed to have I didnt think this was operating correctly but it did maintain a set temperature.
Is this the experience others have had in cold weather. When I had my Cardinal 5er the furnace didn't run nearly that often.

I too have the problem.
My furnace seems to run constantly. It only shuts off for a minute or so at a time then starts right back up. And the air dosen't feel very warm when it cycles so fast.
My heat pump does the same thing.
I think we need a new thermostat that lets the temp. drop a couple degrees before it starts the heat back up.

I think that there is not enough temature veryation.
I also think that it makes the furnace waste alot of heat by not letting the heat exchanger get very hot while most of the heat just blows outside from the exaust.

My sensor is above my desk, in the left rear..

[Huck]

the furnace would run for quite a while then shut off for a minute or less then start up again and run for quite a while and then shut off for a minute and so forth. With all the insulation I am supposed to have I didnt think this was operating correctly but it did maintain a set temperature.
Is this the experience others have had in cold weather. When I had my Cardinal 5er the furnace didn't run nearly that often.

I too have the problem.
My furnace seems to run constantly. It only shuts off for a minute or so at a time then starts right back up. And the air dosen't feel very warm when it cycles so fast.
My heat pump does the same thing.
I think we need a new thermostat that lets the temp. drop a couple degrees before it starts the heat back up.

I think that there is not enough temature veryation.
I also think that it makes the furnace waste alot of heat by not letting the heat exchanger get very hot while most of the heat just blows outside from the exaust.

My sensor is above my desk, in the left rear..

[bstark]

From what information being provided; furnace running but not heating unit enough to trigger thermostat shut-down, I would suspect the problem is with the furnace and it's supply ductwork to trailer. There really shouldn't be any problem with the air coming from the furnace being warm as these furnaces are at least 35,000BTU's rated by D/T to produce 42,000BTU's through the use of a redesigned (tapered) plenum duct on the rear of the furnace. A run time of a few minutes should result in you noticing very warm air from floor ducts in living room/kitchen area.

A furnace that is running but not producing heated air that is almost too warm to stand with a bare foot on the floor grills is not functioning correctly and should be checked out viv-a-vis burner performance.

I would start my investigation by checking the ductwork right at the rear end of the furnace and if it's very hot there, following the plastic ducting to their respective connections to the metal floor ducting. If there is not significant heat right at the rear of the furnace you have a burner/gas supply problem.