Help - no heat

[HMXDave]

I had an issue with my AC not working....took it in for warranty (http://www.irv2.com/forums/f54/stran...on-101081.html )

Anyways...now I am out in the boonies and my regular gas furnace does not work. At this moment I have the genny going and the heat pump is on...but the furnace does not work. It is going to be close to freezing tonight...Any ideas? What would they have fooled with? I am right flippin mad....

[336muffin]

Dave, clean out the burner, 1 tiny spider web will stop it from lighting! Is it getting power? will the fan run? Most of the time it's something simple, do you have mud dobber screens on the outside vents? Let us know if you get it fired up.

[336muffin]

When you get the outside cover off, check for corroded wires, they are exposed to the elements. Good luck!

[Mafiaman]

You may try bleeding gas line to heater, If they do not ignite they safely shut down.
And lack of gas may prevent lighting.

Do you smell gas outside by the heater vent?

[nosticks]

Here are two sources of information on appliances anyone owning an RV should have.

RV Furnace Trouble Shooting - RV Furnace Trouble Shooting Page

Service Documents

[HMXDave]

Well...two nights at below freezing with no furnace. THAT was fun. Good thing it was a guy's weekend and the DW was at home as she would not have appreciated the adventure.

I noticed when I had the rig in for no A/C that the thermostat has a phone line to the rear of it. This phone line connects to another electronic board in the A/C unit. From there, that board controls what runs, be it A/C, heat pump, or furnace. The furnace ran days before it went in (it's a new rig) for warranty...so I'm real sure it's not a burner or fuse issue. There is no clicking or fan or anything...

Anyways...home now and I will take it in again tomorrow. What a pain....

[Dave78Chief]

Not sure if you want to comb through all this information in order to understand how this all interacts together but I would reccomend you keep them for furture reference in case a service center needs them:
Note: Furnace manual is totally seperate form this information. The Comfort Control Center (CCC) just turns furnace On and Off via the control box connection in the forward AC unit (2 blue wires).

1) Duo-Therm Penguin Unit Installation: http://www.dometic.com/1f24ead8-6316...87ce6bad.fodoc
Wiring connections on pdf Page 13
Connection Schematic on pdf page 19

2) Duo-Therm 5 button Control Center Operators Manual: http://www.beamalarm.com/foretravel-...108664-040.pdf

3) Troubleshooting the Duo-Therm 5 Button Control Center: http://bryantrv.com/docs2/docs/ccc5.pdf

4) Troubleshooting Duo-Therm AC and Heat Pump Systems: http://bryantrv.com/docs2/docs/acservice.pdf

For furnace operation, a relay (controlled by CCC) in the front AC control box connects/disconnects the 2 blue wires together turning the furnace on and off.

Dave

[HMXDave]

Originally Posted by Dave78Chief

The Comfort Control Center (CCC) just turns furnace On and Off via the control box connection in the forward AC unit (2 blue wires).

Hehehe...THIS is the info I needed 2 nights ago. I would have jumped up on the roof with a flashlight and open the cover if I thought there was something I could do. I assume these wires were compromised when they worked on the A/C. Thanks for the info....I'll do some reading.

[wa8yxm]

Originally Posted by 336muffin

Dave, clean out the burner, 1 tiny spider web will stop it from lighting! Is it getting power? will the fan run? Most of the time it's something simple, do you have mud dobber screens on the outside vents? Let us know if you get it fired up.

Nomination for best suggestion.. And I will add another.

My parents, in their 2nd house, had a serious "Work when it feels like it" problem with the oil fired furnace... I mention this only because the LP furnace (AN Attwood) in my coach did the exact same thing last spring.

They ask me to look at it (years ago) .

Turns out the ignition points (Both are DSI) were not properly gapped.. With the manual in one hand and a ruler in the other I measured the oil furnace gap at FOUR TIMES the recommended setting.. Re-set per the manual, and it worked perfectly after that.

On my coach it was closer to 2 times.

Another issue is battery voltage and connections:

The heat cycle:
T-Stat calls for HEAT
Blower starts.. When the blower is moving air fast enough a sail switch closes and signals for burner start.. The control board then sends power to the solenoid, opening the valve, and to the ignightor, it watches for flame and if it fails to see flame it shuts off for a bit, then tries again. Usually up to 3 tries. If it sees flame it keeps the fires burning till the T-state says "Enough"

Low voltage means low speed on the blower and no heat

Obstructed heat ducts or registers = low air flow = No heat

[Dave78Chief]

HMXDave,
All of the points everyone is making are valid. If the 12VDC supply to the furnace is ON at the DC distribution panel, then the 2 blue wires act as the thermostat ON command. If the furnace doesn't work at that point, you then have to use furnace troublesooting procedures like what nosticks reffered to

RV Furnace Trouble Shooting - RV Furnace Trouble Shooting Page

Service Documents

While controlled from the Duo-Therm CCC, your furnace is seperate appliance.

Dave

[HMXDave]

Originally Posted by Dave78Chief

HMXDave,
All of the points everyone is making are valid. If the 12VDC supply to the furnace is ON at the DC distribution panel, then the 2 blue wires act as the thermostat ON command. If the furnace doesn't work at that point, you then have to use furnace troublesooting procedures like what nosticks reffered to


While controlled from the Duo-Therm CCC, your furnace is seperate appliance.

Dave

I realize this....and would agree had the unit not worked days before it went in for AC problems. They had the CCC all apart and had the board out of the roof unit....now the furnace won't do anything. No changes other than that. I'll bet the farm the goon that 1/2 fixed my AC, fouled up the connection to the furnace somehow.

I have all the links saved for future reference when warranty is over. Thanks all. Rig goes in Wednesday....I will update the results. They better fix the AC correctly this time, too.

[JimM68]

I'm with Dave on this one.
And BTW Dave, thanks for the documents, that is the same stuff that's in my 08 monaco.

["007"]

Dave if your dealer can not get all working properly with all the advise and pdf's you have in hand maybe you should contact Newmar Repair center and explain the situation.
Newmar has AC techs come into their center to work on them they do not repair themselves.
You will need your coach build number and they may refer you to local AC repair center for model you have on coach.

[HMXDave]

Well the local RV shop (working through the RV Care program and Newmar warrenty) can not fix it after having my rig 9 days. Disgusting. So...I pick it up today and drive it to my dealer an hour away (and get the DW to come pick me up) so they can have a crack at it. I'm sure that with the data you gents have provided, I personally could have diagnosed the issue....I mean, this is pretty simple technology. I'm sure Newmar is going to have something to say about the hours charged to their warranty with no results....