Tiffin Tech Talk – Winter 2026

Furnace Turning Off Early

2019 Phaeton 40 IH. The furnace will turn on initially but goes off before reach temp set for furnace (65 degrees). If I reduce temp to closer with 5 degrees of actual inside temp furnace comes back on. Happened 2 mornings in a row 52 degrees inside coach this morning and 45 degrees yesterday morning inside coach. Both times we set furnace at 65 to warm up inside when we got up.
-Cynthia Hare
2019 Phaeton 40 IH

Dear Cynthia,

 If the roof air conditioner is turning on and off at the correct temperatures, the temperature sensor is likely not the issue. A service technician should check the furnace temperature sensor and inspect the ducting for any damage or restriction.

Flooring Replacement

I have a 2020 Open Road 36 UA. The floor is decomposing, can you please advise what thickness plywood in under the floor tile?
-Duane Rice
2020 Open Road Allegro 36 UA

Dear Duane,

 The flooring thickness is 5/8 inch.

Byway Battery

My 2025 byway will not start and I believe the chassis batteries have died. It is in storage, plugged into shore power. The control panel shows power going to the house batteries but nothing going to the chassis batteries. I tried the aux star, the dash would light up, but would not start. Not sure if I have some set wrong on the control panel or to charge the chassis batteries or what. Any help would be appreciated.
-Jeffrey Phelps
2025 Byway

Dear Jeffrey,

The Byway does not charge the chassis battery when connected to shore power. To keep the chassis battery maintained, a power outlet can be installed near the chassis batteries and a battery maintainer (Battery Minder) used while plugged into shore power.

Phaeton Electrical Issues & Resolutions

Hello, we just purchased a 2013 Phaeton and I have a couple of issues and a question. #1. There 2 12volt cigarette lighter style plugs on the dash and neither have power. I’m wondering if they are fused and where the fuses may be located. #2. I have had issues with the automatic steps opening and closing while going down the road I know where the switch is but is there any adjusting it or would there be another issue? My last question is about how to access the back of the tv in the front of the coach between the 2 front seats.
-Ken Degler
2013 Phaeton 40 QBH

Dear Ken,

• 12-Volt Outlets: If the 12-volt outlets are not working, please check the fuses on the Roanoke electrical board. A reference card should be attached to the board showing which fuses control the outlets.
• Entry Steps: The step switch located inside the door frame controls step operation. If the steps are not working correctly, there may be a loose connection behind the switch. The switch can be removed to inspect the wiring. If the wiring is secure, the switch itself may need to be replaced.
• Front TV Access: To access the front TV, remove the two access panels inside the cabinet. Remove the two mounting screws, then lift the TV up and off the bracket to access the connections behind it

Windshield Cracking

2012 32 Ca windshield cracked after 10 years. Reinstalled in 23. Cracked again in the same place, driver side bottom corner in 24. Replaced. Popped out of frame recently. Reinstalled but cracked again in same place! How do I prevent this from happening again. ChatGPT acknowledges the problem.
-Bill Fratus
2012 32 CA

Dear Bill,

All Tiffin windshields are replaced by David Hester, owner of First Class Glass, located across the road from Tiffin Service. He is highly experienced with Tiffin coaches and can assist with windshield replacement and questions. He can be reached at 256-810-9974.

DC Power Loss

Intermittent loss of DC power. Nothing specific causes DC power loss. Maybe a light, a fan or just spontaneous. All good after resetting the DC disconnect switch at the door entry panel. Wondering if a bad DC relay (which is in the electric bay under driver seat) as everything seems to be ok. Also was going to try a purchase a replacement, but it is a hard to find part.
-William Patton
2016 Allegro Red 38 QBA

Dear William,

If your 2016 RED is losing interior 12-volt power, the issue may be related to the Spyder power module located in the front driver-side storage compartment. This module controls power distribution to interior items such as lights, fans, and furnaces.

Onan Generator Switching Off

I have a 2014 Allegro Open Road 31SA with an Onan 7000-watt generator.
The 2 30-watt breakers are both switching off when running the front AC unit while driving.
I am not running both AC units at the same time.
I have tried running the rear unit, but the same problem occurs.
-Richard Nestor
2014 Open Road Allegro 31 SA

Dear Richard,

If the generator’s main breaker trips, it may be due to excessive electrical load. We recommend having a service center check the air conditioner’s startup and running amperage, as well as the total electrical load while all systems are operating.

Fridge Power Off

We have a 2025 Phaeton and unlike our 2015, the refrigerator panel on the front does not appear to give me the ability to turn the frig off. What am I missing?
-Ken Harms
2025 Phaeton 40 IH

Dear Ken,

To completely turn off power to the refrigerator, switch off the refrigerator breaker located in the rear 50-amp breaker panel. The refrigerator does not have its own power switch.

Slide Out and Jacks Issue

This is in response to:
Issue with Jacks and Front Slides
In order to get jacks and front slides to work, I have to gently tap on the pump motor with a small hammer while my wife pushes the button for jacks or slides. Solution?
-Gary Hans
2015 Allegro Bus 45 LP

I have a 2019 RED 37BA and had this problem for several years. The hammer tap worked and saved me on many occasions.
After replacing both solenoids the problem still persisted and the hammer tap continued to save me.
Knowing that I didn’t want to rely on a hammer to get the hydraulic system to operate I turned to HWH.com and followed the troubleshooting instructions.
I discovered that the main ground cable to the motor is supposed to be attached in a specific order. That cable needs to be first and but in my case it was attached last.
After correcting the ground connection per the HWH instructions the problem has been solved. I still have the hammer available just in case.
-Mark Tang
2019 Allegro RED 37BA

Dear Mark,

 If the slides or leveling jacks only operate after tapping on the motor, this usually indicates an internal motor issue. A technician should check power and ground connections, but the motor will likely need to be replaced.

Key FOBs Stopped Working

I have a 2021 Allegro Red 37BA. Both my TriMark door entry key FOBs stopped working, I replaced the batteries in both, but they still don’t work. I was told I need to reset the TriMark control module. I looked in all the underneath storage bins and cannot find it. Plenty of other electronic stuff but nothing stating it is TriMark. Where exactly is the control module located?
-Dana Wright
2021 Allegro RED 37BA

Dear Dana,

 If there is no Trimark module located in the cargo bays, the key fobs may need to be re-synchronized at the Spyder control panel inside the coach. This can be done through the Settings and Wireless Settings menu on the panel by following the on-screen instructions.