Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Jimmyjnr on November 11, 2014, 07:42:43 am

Title: Atwood furnace
Post by: Jimmyjnr on November 11, 2014, 07:42:43 am
Front furnace works great , rear furnace starts with cool air , warms up ( but not to temp of front , then back to cool air then shuts off . This cycle keeps repeating at thermostat calls for heat .
Since airflow is good , does it indicate thermocouple ??
Title: Re: Atwood furnace
Post by: Jimmyjnr on November 11, 2014, 08:32:31 am
Exhaust from rear furnace does not feel as strong as front unit , not scientific , just a cold hand against it
Title: Re: Atwood furnace
Post by: wolfe10 on November 11, 2014, 08:49:24 am
Lower air flow could be due to a number of causes, but can easily cause your symptom.

First check if for voltage at the furnace (lower outside furnace cover to access).
Title: Re: Atwood furnace
Post by: nitehawk on November 11, 2014, 09:15:03 am
Does your manual indicate size/output of your furnaces? Usually the rear furnace is smaller. I think it may be because the bedroom area is usually not kept as warm as front of coach, and has fewer windows.
Title: Re: Atwood furnace
Post by: Jimmyjnr on November 11, 2014, 12:47:57 pm
Just stopped for quick break and cranked rear furnace to check symptoms , fan sounded rough and slow on start up .
Moves me toward Brett's idea , voltage or bad fan .
Does the list of repairs ever get shorter ???
Title: Re: Atwood furnace
Post by: Jimmyjnr on November 11, 2014, 02:04:31 pm
Brett
When I check for voltage should furnace be switched on and thermostat calling for heat . ??
Title: Re: Atwood furnace
Post by: wolfe10 on November 11, 2014, 02:22:18 pm
Brett
When I check for voltage should furnace be switched on and thermostat calling for heat . ??

Yes, I would check it under load.  A bad or corroded connection "upstream" or on the ground side (just as likely) could read good voltage under no load, but drop like a pet rock under load.
Title: Re: Atwood furnace
Post by: bbeane on November 12, 2014, 05:45:33 am

Does the list of repairs ever get shorter ???
In a word no, ya just have to learn to live with some not so important small things until you can get to them.
Title: Re: Atwood furnace
Post by: rsihnhold on November 12, 2014, 08:56:25 pm
In a word no, ya just have to learn to live with some not so important small things until you can get to them.

 ^.^d  Truer words were never spoken.
Title: Re: Atwood furnace
Post by: nitehawk on November 13, 2014, 07:49:14 am
One also has to learn which small items can turn into major problems that will bite you hard if not addressed quickly.
Title: Re: Atwood furnace
Post by: Jimmyjnr on November 13, 2014, 10:37:59 am
Checked the furnaces and front is double the output of the rear , consumes twice the current which must relate to motor size and air flow ??
Title: Re: Atwood furnace
Post by: Bill Willett on November 13, 2014, 12:18:19 pm
It appears that the rear furnace is 16,000 BTU's and the front is 35'000. See the specs on Barry B's page.
Title: Re: Atwood furnace
Post by: Jimmyjnr on November 13, 2014, 01:07:12 pm
Seems crazy since the rear also heats the wet bay and tanks ?
Would it be possible to fit larger furnace or would electrical / propane feed need to be upgraded
Title: Re: Atwood furnace
Post by: Caflashbob on November 13, 2014, 02:08:40 pm
Seems crazy since the rear also heats the wet bay and tanks ?
Would it be possible to fit larger furnace or would electrical / propane feed need to be upgraded

Bigger rear furnace would add to the short cycling it already has.