Furnace Issues

Chiefbvfd · 05-19-2014, 04:35 AM

We were out this weekend in Eastern Illinois. We use the Heat Pumps about 99% of the time when the temps get cool, but Friday night it dropped down to 35 degrees and we had to fire up the furnace (only the third time since we've owned our Journey). I switched the thermostat to "Gas Heat" and the furnace came on and warmed the MH up nicely. We went to bed and I woke up at 1:00 AM and it was 62 degrees in the Motorhome. I played with the Thermostat and could not get the furnace to kick in. I shut everything off and I heard a "click" either from the thermostat or from the furnace. I then set everything back to "Gas Heat", and the furnace took right off, and run OK the rest of the night. In the morning, once the outside temp got around 45 I shut down the gas and went back to the heat pumps. Saturday nighty the temp dropped down into the 30's again and I fired up the gas furnace and it did the same thing. I had to get up in the middle of the night and shut everything down and start over and it ran the rest of the night. It is a Suburban furnace, I don't know the model number right off hand. I looked at the manual and there wasn't much there. Does it operate like a home furnace, where it brings in combustion air and if everything isn't satisfied it won't light???? Any help will be appreciated.......

skigramp · 05-19-2014, 05:49 AM

It sounds to me like you have a defective thermostat ...

The thermostat on our 2004 Journey was behaving poorly about a year after we got the coach ... I called the thermostat company ... they asked me for the model / serial number ... they sent me a new one ... I replaced it ... that was the end of the problem.

Lanny1763 · 05-19-2014, 10:07 AM

Chiefbvd:

We have a 14 Itasca Solei and ours did the same thing. We took it into a dealer and the tech pulled the cover off the thermostat and inside was a small fuse. He pulled that fuse and then replaced it back in its holder, which he said resets the thermostat. So far so good on ours.

Lanny

mel s · 05-19-2014, 10:34 AM

Quote:

Originally Posted by Chiefbvfd

It is a Suburban furnace Does it operate like a home furnace, where it brings in combustion air and if everything isn't satisfied it won't light????

Chiefbvfd
It does.

Multiplethings affect the operation of RV furnaces.
See your Suburban Owner's Manual and/or:
Marksrv.com rv furnace troubleshooting

Mel
'96 Safari

Hikerdogs · 05-19-2014, 02:13 PM

You didn't tell us what temperature you set the thermostat. Generally the furnace doesn't kick in until the actual temperature in the coach is at least 2* below the set point. Sometimes the restart temperature can be as low as 5* below the set point.

There have been a few threads over the years as how to recalibrate the thermostat. You might want to search the subject. There have been many detailed descriptions on how to do it.

grtharris · 05-19-2014, 08:32 PM

Make sure there is not anything blocking the cold air return to the furnace. If there is it can cause the furnace to over heat and shut down requiring a reset by turning it off then back on.

Yoda2405 · 05-19-2014, 09:00 PM

My furnace in the same unit as yours has done this since day 1. The dealer found no problem, Winnebago said they could not find an issue but finally did replace the control board in the furnace. I had previously replaced the thermostat. Over time the problem has seemed to fix itself to some degree but once in a while it still does the same thing. The easiest way I have found to get it working is turn the thermostat off wait for the click and then turn it back on. Sometimes it will cycle on and off all night and sometimes it "locks up" and requires cycling the thermostat.
Very frustrating but I have yet to find the actual cause, but time does seem to have it working better.
Good luck, and if you find a resolution, please post it.

David

Chiefbvfd · 05-20-2014, 04:51 AM

Thanks for all of the suggestions. Hikerdogs, the thermostat was set on 76 and the actual temp in the MH was 62. Yoda2405, we use the furnace so rarely it may be something we can live with, now that I know how to get it running again. Thanks to all of you again and if I find a solution I'll be sure and post it.....

ChasA · 05-20-2014, 07:08 AM

Have your LP pressure checked. I went through replacement of thermostat and control boards to no avail. The techs finally checked the LP pressure and found it to be only 7.5 inches. They replaced the regulator. I have only used the furnace 1 night since then and it didn't fail that night. I'll probably not use the furnace 'til next fall.

wa8yxm · 05-20-2014, 07:17 AM

I am hating the internet here today.. Keep having to re type stuff

One thought: If the batteries are running down due to a converter that's not up to needs or due to bad connections then..
First attempt. Battery good enough, fan comes up to speed sail switch swails, switches and furnace works. but blower motor takes batteries down and by the time try 2 comes along the batteries have not recovered. During lock out time the batteries recover and without lights and such hold the rest of the night.

Not the only explanation, nor even the most likely, but just one.

It could be, as others have suggested, the T-Stat

or the control board on the furnace

or a bad connection both in and leading to the furnace.

or even the spark gap on the DSI ignition system. I have seen that on 2 out of 2 furnaces I've worked on.