Tiffin Tech Talk – Winter 2025

Removing Fireplace For Maintenance

We have a water leak coming from underneath the fireplace. We have looked on the roof and basement and everything is dry with no luck finding where the water is coming from. We are hooked to city water. Logically it is coming from the shower but we can’t get to the waterlines. We called into the service center and the tech said we would have to take the fireplace front off to get access to the 4 screws that hold the fireplace in place. Then we can pull the fireplace out to get access to the space in between the shower and TV / fireplace. How does the front glass come off? We looked and don’t see anything that would release it and don’t want to pull too hard in fear of breaking it. Any help would be appreciated!!
-Denise Holsinger
2021 Phaeton

Dear Denise, The fireplace front will come up by lifting the glass straight up. There are prongs around the glass that holds the front glass on the fireplace. Once you get the glass off, you will be able to see the 4 screws that you can access to take the fireplace out of the hole opening.

Air Bags Leaking

I have a 2025 40-ft Allegro Bus. I have it in for service and one of the issues is over night the air bags leaks out. This has not happened before with this coach or my 2021 bus. The tech at the dealership tells me it is normal. What’s up?
-Thomas Gayer
2025 Allegro Bus 40 IP

Dear Thomas, Some loss of air from the front and rear air storage tanks is considered normal. A drop in pressure of 10 PSI an hour or more should be addressed by an authorized service shop. A leak of less than 10 PSI an hour will often be difficult to locate and should cause no operational issues with the vehicle. Air leaking from the suspension air bags usually presents itself by the coach leaning after it has been sitting for a period of time. If the coach is leaning after sitting for just one night a service tech should be able to locate and correct that leak.

Plugged Into Shore Power – House Batteries Down

I am plugged into shore power and my house batteries are down to 60%. What could be the issue?
-John Wolford
2024 Open Road Allegro 36 UA

Dear John, When plugged into shore power, the combo inverter should be charging your house batteries. We would recommend to inspect your inverter and confirm that the resettable breaker is not tripped as well as looking on the main touchpad of the RV and ensure that shore power is getting to the transfer switch to the inverter and that inverter is turned on.

Accessing Washer Filter

Our 2023 Allegro Bay 38AB has the washer on the floor in the left closet of the bedroom. Due to the door frame that the closet door slides on, we cannot access the washer filter clean out. How would we do this filter maintenance?
-Troy Rader
2023 Allegro Bay 38 AB

Dear Troy, Taking the closet door off of the guide system would be the best way to access this area if the door is blocking the filter housing. To take the door off there will be small clips on the end of the guide that you would press in to release the inner guide from the outer guide. You would need to do this for both top and bottom guides.

Light Fixtures Over Bed

What light bulb goes in the sconce light fixtures above the bed in my 2014 Allegro Bus?
-Kenneth Johnson
2014 Allegro Bus 40 QBP

Dear Kenneth, These LED lights will not have replaceable bulbs, the light assembly would need to be replaced. You can reach out to our Parts Dept (256-356-0261) for the light assembly.

Torque Specs For Oil Pan Bolts

What are the torque specifications for oil pan bolts on my 2008 Tiffin Allegro Bus ISL 425?
-Rick Ahart
2008 Allegro Bus 40 QRP

Dear Rick, The Cummins Service Manual for your engine shows the oil pan bolt torque value to 248 in-lbs.

Attaching Water Hose to Fresh Water Fill

We have a 2013 36 LA Allegro Open Road, which we love. It allows us to fill the fresh water from either side. In the sanitation compartment, there is a threaded connection. On the other side there is not (other than the supplied cap), making it difficult to keep the hose in that port without holding it in place. Do you have a suggestion as to how we can attach a water hose to it?
-Shawn Benham
2013 Open Road Allegro 36 LA

Dear Shawn, The wet bay area is the ideal spot to fill your fresh water tank when you have access to shore water. This port is designed to work with pressurized water systems. The secondary fresh tank fill, located on the passenger side, is primarily used when boondocking.

Here’s the key difference: The wet bay fill requires a minimum of 40 PSI to push water past the check valve. If water pressure is too low, it may not fill effectively. On the other hand, the passenger-side fresh tank fill does not have a check valve and does not require any minimum PSI. This allows you to fill the tank easily, even when using low-pressure water sources like a portable container or gravity-fed system.

Both options provide flexibility to keep you supplied with fresh water, no matter where your journey takes you!

A/C Temperature Sensor Sensitive to Sunlight

My front A/C temperature sensor seems to be very sensitive to sunshine. When the A/C’s are running in my covered garage, the front sensor reads correctly but when the rig is sitting in the sun, it reads several degrees higher resulting in the front A/C running continuously and over cooling. It also works properly at night. At night, it reads and cools correctly. I have checked the sensor wire butt connectors, they seem to be fine. Any suggestions on where to trouble shoot next?
-David Handy
2023 Allegro RED 360 33 AA

Dear David, The thermistors used to monitor zone temperatures are indeed sensitive to direct heat sources like sunlight. To ensure accurate temperature readings, try using your window shades to block sunlight from shining directly on the sensor. This simple step can help the thermistor measure the true ambient temperature in that area, allowing your system to maintain a more consistent and comfortable environment.

Issues with Sani Flush

My Sani Flush will not let any water from the garden hose into the system. I have checked the back flow preventer under the kitchen sink. It does have about 1/2 full in the bottom chamber.
-David Karbey
2021 Allegro Bus 35 CP

Dear David, The flush system includes a vacuum breaker in line before water enters the black tank. If your shore water pressure is below 40 PSI, the water may not have enough force to pass through the system’s check valve and enter the motorhome.

We recommend confirming that your water source is providing at least 40 PSI. If you do have sufficient pressure and the issue persists, the next step would be to inspect the vacuum breaker. If you need assistance locating this part, feel free to give us a call — we’re happy to guide you through the process.

If the vacuum breaker needs to be replaced, the good news is that it’s a simple task. The fitting is hand-tightened, making it quick and easy to swap out.

Putting Down Levelers To Take Pressure Off Tires

I store my 37 RED all winter. Should I put the levelers down to take pressure off of the tires?
-Roger Ganger
2020 Allegro RED 37 PA

Dear Roger, When storing your motorhome, it’s a good idea to use the leveling system to keep it properly leveled. This helps prevent tire flat-spotting, protects suspension components by reducing strain on parts like springs and shocks, and enhances overall stability and safety during storage. It’s important not to fully suspend the tires off the ground. Instead, allow them to remain lightly touching the surface to avoid unnecessary strain on the leveling system. To protect your tires from sun exposure and prevent UV damage or cracking, consider using tire covers during storage.

Using Heat Pumps To Keep Pipes From Freezing

Can I set 1 of my heat pumps using gas only to heat to 49° without using shore power or generator? Just trying to keep my pipes from freezing until Monday when I can get my RV winterized. Today is Friday. I do have 2 solar panels keeping my house batteries charged and did not turn on the Inverter.
-Jill Merrill
2023 Open Road Allegro 32 FA

Dear Jill, The heat pumps in your motorhome are 110V only, meaning you will need to be connected to shore power or have your generator running when using the heat pump. Additionally, the outside temperature must be above 40°F for the heat pump to operate effectively. If the temperature drops below 40°F, you’ll need to rely on the furnace as your primary heat source.

Synchronizing Schwintek Slides

What is the best way to synchronize the rear Schwintek slides?
-Jim Paul
2021 Allegro RED 33 AA

Dear Jim, To synchronize the rear Schwintek slides in accordance with Lippert Components standards, first ensure your motorhome is connected to shore power or running on the generator. Extend the slides fully, checking for any uneven movement. If the slides are not moving in sync, briefly press the retract button on both sides to reset the system. Schwintek systems allow recalibration by holding the extend/retract button for several seconds. After making adjustments, test the slides to ensure they move evenly. For persistent issues, consult a professional technician. Regular maintenance, such as cleaning the tracks, will help keep the system in proper working order.

Connecting RV to 20A Outlets

We store our 2021 Tiffin Breeze in an enclosed garage that is equipped with 115V/20A outlets. What is the recommended procedure to connect the coach to this outlet type and ensure that the chassis and house batteries remain charged while in storage? I am of the understanding that you first select the 20A maximum shore power on the Magnum Energy panel, make sure all electrical loads in the coach are turned off (lights, refrigerator, etc.), plug into the shore power source with a 15A to 50A adapters and then leave the chassis and house battery isolator switches on. I was told that if the battery isolator switches are turned off the on-board charger cannot charge the batteries. Is that correct? Also, is it true that GFIC outlets can be problematic if an RV shore power cord is plugged into them as in this case?
-Richard Mertens
2021 Allegro Breeze 33 BR

Dear Richard, To properly store your 2021 Tiffin Breeze in an enclosed garage with a 115V/20A outlet, first select the 20A shore power setting on the Magnum Energy panel to limit power draw. Make sure all electrical loads, including lights, refrigerator, and air conditioning, are turned off to prevent overloading the circuit. Next, use a 15A to 50A adapter to connect your RV’s power cord to the 115V/20A outlet, ensuring safe power distribution. It’s important to leave the battery isolator switches on so the onboard charger can charge both the chassis and house batteries; if the isolators are turned off, the charger will not function. Lastly, while it’s true that GFCI outlets can sometimes trip when used with RV shore power cords, it’s advisable to use a standard 115V/20A outlet without a GFCI if possible, or to equip the RV with a surge protector to minimize the risk of tripping the GFCI. Following this procedure will help ensure that your RV’s batteries stay charged during storage without any issues.

Winter Storage

Winter Storage: I am storing our Bus inside for four months. I usually fill the fuel tank and add Seaform additive. What about water? Should I fill the fresh, grey, and black tanks or empty?
-David Eberly
2018 Allegro Bus 40 AP

Dear David, For winter storage of your motorhome, it’s recommended to empty the fresh, grey, and black water tanks to prevent any water from freezing and causing damage to the tanks or plumbing. You should also drain the water lines and add non-toxic RV antifreeze to the plumbing system for added protection. Similarly, empty both the grey and black tanks to avoid waste freezing inside and potentially damaging the valves. After emptying, adding some RV antifreeze to the waste system can help protect it as well. As for the fuel tank, it’s a good idea to fill it and add a fuel stabilizer like Seafoam to prevent fuel degradation and ensure smooth engine startup when you’re ready to use the RV again. By following these steps, you’ll help protect your motorhome from freezing issues and keep it in good condition during storage.