Another heater question

Refrigerator, stove, furnace, water pump, air conditioner, microwave, water heater, fans, lighting
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craigmar
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Another heater question

Post by craigmar »

While on another outing in Idaho, we were hooked up to shore power and bcause of the temp, we had the heater going. Everything was fine the first day and we were nice and cozy, however, on the second day the heater quit and had it not been for the aux heater on the air conditioner we would have been quite frozen for the rest of our time. In reading the various posts about heater problems, I am asking for help. In the past my wife and I usually are in uninproved campspots and upon needing the heater or air we have used the genset to power it. This is the first time we have had to use the heater in an improved spot and so I thought that this time the shore power would take care of it but found out later on another post that listed a different site for the heater, that the unit is not powered by shore power but by the vans battery, that would account for having to get a jump on our dead battery when we were ready to leave. Both batteries have been recharged, gas is full but the heater will not run, besides checking the various solutions in previous posts short of replacing the computer board which will be my last effort, I am wondering if there are any hidden breakers I need to look for or am I overlooking something not put in the posts. Thanks for your help, also am I wrong to think that the heater was running off the gen set or was I just lucky that time. This is our first RV and it seems like there is always something new to learn
Our van by the way is a 1991
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Alaskan
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Post by Alaskan »

Craig...

First off, the fan motor in the furnace is 12 volt, and as you discovered, the on-board battery charger may not keep the house battery charged enough to keep the furnace running for an extended length of time, if your converter/charger isn't putting out the voltage that it did when new..

The basic's first..under the front cover on the furnace, over at right you'll see a circuit breaker, white button with the number 5 on top of it, shown on page #8 in your Owners Manual, front page on the hydro flame corp "Trouble Shooting Guide"...5 amp circuit breaker, should be in the down position

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Next...under the thermostat, check the level to make sure its set to ON vs.OFF, lever to the left would be ON.

Image

Open the cover on your charger/breaker panel under the couch...3rd fuse from the left in the 12volt section is a 15 amp fuse that is directly related to the furnace...

The 12 volt section is at right...

Image
Last edited by Alaskan on Tue Jan 19, 2010 2:07 pm, edited 9 times in total.
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skater
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Post by skater »

In my '91, the furnace is connected to the coach 12-volt system, not the engine battery. That'd be an incredibly stupid setup (for the reason you mentioned - you could be stranded), and I hope Airstream wouldn't have set one up that way. Moreover, the point of the coach battery is specifically to run 12 volt appliances when you don't have 120 volt power available.

I suspect something went bad with the furnace - probably the board. Like Alaskan said, though, check the basics. Also, check that the thermostat is actually sending power to the furnace, and be sure the furnace has power and ground (it's not hard to figure out which wire is which - there aren't that many).

Alaskan, the on-board converter should handle the furnace running without a problem. It's a 30 or 32 amp charger, which should mean it can run the furnace (15 amps max - probably more like 7 amps normally) with ease. If it can't, the converter is probably bad - and it is almost 20 years old. I replaced my converter with a new three-stage model a year or two ago because it was putting out low voltage (something else to check, craigmar - disconnect the coach battery, plug the camper in or fire up the generator, turn off all the 12 volt appliances, and see what voltage the system has - it should be at least 13.2).
1991 Airstream B190 - bought, 2005; sold, 2011; bought 2017
1995 Airstream Excella 30' trailer

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Alaskan
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Post by Alaskan »

Good point...never considered that the converter/charger might not be working to its original max output...

Could also be a coincidence that the thermostat correctly isn't working now also.

Condition of his house battery and it ability to take a charge..

Another test of a converter/charger would be to disconnect the house battery, plug the rig in and see if a furnace will fire up and run
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craigmar
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Another heater problem

Post by craigmar »

Well, the heater is working and I am amazed at how dumb I am and how simple the solution was this time. When Alaskan mentioned the breaker, I again took a look at the front of the heater and in the upper right hand corner found the small breaker had been tripped. For being ignorant, my wife and I could have spent some cold nights had it not been for the aux heater on the air conditioner. If a person goes to Alaskan's picture that was posted on Nov 6th of 07,("another furnace question") you will see it shows the front of the heater with all the covers still attached, my breaker was located on what looks to be a small box in the upper right hand corner with one screw, the breaker was sitting on top of that box.
This problem while now being solved, brings up another question or two. 1st, why would that breaker trip? 2nd, how do you use the heater for more than a day without draining the batteries, other than having a solar charger if the sun were available, do you start the vehicle and run it for awhile, could you plug in a charger unit to your gen set or shore power and keep it charged. 3rd, if I am reading Skater correctly, then the shore power should run the heater and the converter should be charging the battery, maybe its time to change the converter in this unit also. What do you experienced winter campers do. Thanks again for the info, Craig
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skater
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Re: Another heater problem

Post by skater »

craigmar wrote:Well, the heater is working and I am amazed at how dumb I am and how simple the solution was this time. When Alaskan mentioned the breaker, I again took a look at the front of the heater and in the upper right hand corner found the small breaker had been tripped. For being ignorant, my wife and I could have spent some cold nights had it not been for the aux heater on the air conditioner. If a person goes to Alaskan's picture that was posted on Nov 6th of 07,("another furnace question") you will see it shows the front of the heater with all the covers still attached, my breaker was located on what looks to be a small box in the upper right hand corner with one screw, the breaker was sitting on top of that box.
Glad it was something simple! Here's a link to the thread with the pictures.
This problem while now being solved, brings up another question or two. 1st, why would that breaker trip?
Good question. I'd keep an eye on your furnace. It shouldn't be tripping the breaker unless there's a short or it's drawing too much current.

One thing you might want to do is pull it out (you'll have to disconnect and reconnect the gas line) and just clean it thoroughly. It's not hard to remove or reinstall and there's more than enough wire to get it out to work on it (pull the fuse, though).
2nd, how do you use the heater for more than a day without draining the batteries, other than having a solar charger if the sun were available, do you start the vehicle and run it for awhile, could you plug in a charger unit to your gen set or shore power and keep it charged. 3rd, if I am reading Skater correctly, then the shore power should run the heater and the converter should be charging the battery, maybe its time to change the converter in this unit also. What do you experienced winter campers do. Thanks again for the info, Craig
I usually camp with shore power, but you're right - the furnace will kill the battery pretty quickly (your propane supply, too!). I'd expect to get more than one night out of it, but I haven't actually tried it. Here are some ideas that occur to me:

1. Add an additional coach battery.

2. Look at getting two 6-volt golf cart batteries. My memory on this is hazy but you can hook them up in series and get more current than a single 12 volt deep cycle battery. Do some searching on the internet for this.

3. Verify your converter is working correctly - if it's not fully charging the battery, you're sunk, unless you run the engine a long time. The new converters have 3-stage charging and will maintain your battery without killing it, unlike the original one. I replaced my converter and put a good deep cycle Optima battery in, and I haven't had to worry about it since.

4. Verify your deep cycle battery is in good shape. Specifically, if you're using the original converter, be sure it hasn't cooked it (although it doesn't sound like it has, if you have that much battery power).

5. Solar cells would help, but run the numbers - if the cell produces 50 watts, that's ~4 amps (50 watts/12 volts), which may not be enough to run the furnace continuously. It'll definitely help, of course, but you'll still slowly run down the battery. There are a bunch of sites on the internet you can find that will help you calculate how much solar power you'd need, but you also need to know how much current everything draws. (I'd help by testing mine for you, but it's in the shop having some leaks repaired.)

I haven't had a lot of luck with my furnace. It squeals badly when it runs. I believe the problem is that the bearings on the motor are bad, and unfortunately this is my second motor doing it. I think what happened is that one or both of the fan blades are out of balance, causing the shaft to vibrate. A new motor fixed it for a while, but the root cause was still there, causing it to start squealing too. :( This means I've been using an electric space heater for my winter camping - it works well, believe it or not - but it's a hassle too, especially if you want to camp without 120 volt power.

Also, you probably figured out that the heat strip in the air conditioner doesn't respond to the thermostat, so it'll get the camper nice and toasty... and then keep warming it up even further! In theory you're not really supposed to use the heat strip this way - the manual says it's meant to help take the chill off for a little time in the morning. I haven't had a problem though, except for it getting too warm in the camper.

For the converter: I'll just say that a couple problems I was having went away with the new converter - for example, the florescent lights no longer flicker. The water heater starts up better. The lights don't flicker when the water pump runs. It's great. You can find my writeup about it here. (Note - I see some errors in my definitions of the blinking light - I'll fix that. But everything else should be okay.)
1991 Airstream B190 - bought, 2005; sold, 2011; bought 2017
1995 Airstream Excella 30' trailer

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OnTheRoad
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Post by OnTheRoad »

For what it's worth, I find I can get 3 days (maybe part of a 4th) of using the heater when boon docking.

It doesn't use up all the propane. It drains the battery. I just installed a second coach battery under the couch to help with that on future trips. I am also considering adding a solar panel.
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Post by Alaskan »

Good idea on added a second house battery....

I'd done that in my 1997

so...by this we know that with good batteries the furnace might
run a couple days without either charging via the gen or running the engine
or being plugged in.
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