Installing tankless hot water heater.

[chris77]

I have a 21 momentum 395ms it has a suburban Sw12del. I want to swap out for a tankless. Has anyone done this themselves?

 

[297sox]

I had a 2018 297RSTS travel trailer that I forgot to winterize trailer when our fall trip was cancelled. Cracked the tank. I replaced it with a Fogatti tankless. They have different sized doors for openings. Was pretty simple...Water and gas connections the same. Abandoned gas power feed. Running wire for thermostat was probably biggest hassle.

 

[chris77]

How can I access the back of the heater or will the tank pull out enough for me to disconnect them?
I don’t see how I can get to the back side of the heater

 

[297sox]

I could get access to back from removing drawer in bedroom, but I think once screws were out of from it would pull out enough to disconnect stuff. An extra pair of hands or table to set it on when sliding out is an asset.

 

[Lestatsghost]

I installed one, forget which model I used, on my Reflection 31MB. It wasn’t difficult. Swapped from a gas/electric unit. I got to the rear from the basement area. Just removed the rear wall cover and I could access everything back behind the original unit. I do recall having to get a male to male fitting for the water line on the new tankless. The electric power line was no longer needed. The controller, like 297sox said, was a bit of a pain but I could drill up through the wall bottom plate while in the basement then made a hole in the bathroom wall and used a wire noodle to get the thermostat wire to the hole in the wall. You may have a similar setup on the momentum where the water heater is close to the Nautilus and it’s just behind the basement rear wall. Some contorting needed to be done but it wasn’t bad.

 

[Dr. H.]

I have a 21 momentum 395ms it has a suburban Sw12del. I want to swap out for a tankless. Has anyone done this themselves?

Yes, and it was a nightmare! I have a Grand Design Reflection 303 RLS. The dealer couldn't figure it out because Grand Design doesn't have a standard wiring plan for even the same models. They also don't have a wiring diagram for their products. Lazy days said they also have problems when a customer wanted a tankless in a new Reflection. They pulled a tankless from one of their new rigs and had problems installing it in the one the customer wanted, even though they were the exact same model. When I disconnected the old one to the switches in the upper panel, I found I lost power to the tank level indicators and other switched in the upper panel. The Lazy Daze dealer couldn't figure out why I didn't have power to the new tankless. So, they installed a new fuse in the power panel and ran a new wire to the tankless. That didn't solve the issue of having no power to the tank level indicators. So, I fished a wire from another new fuse in the power panel to the tank level indicator. What I found was Grand Design daisy chained their power from the tank level indicators to the other indicators and this solved that issue. I showed Lazy Days how to install a tankless in the Reflection 303 RLS.

Also, the old water heater power was not connected to the water heater circuit breaker in the power panel as it should have been. When I flipped the circuit breaker to the off position and cut the power cable, I got shocked. I pulled the drawers out and found the power wire was routed directly to shore power. Because I didn't know where the wires on the water heater breaker went, I ran another cable to a new circuit breaker. The way Grand Design ran it was a fire hazard and a hazard to anyone working on the water heater. While I was at it, I opened the side of the bulkhead underneath, and found a rat's nest of cables as well as unused wires and wires that ran nowhere. So, I cleaned all of that up and loomed all the wires into a bundle.

 

[Brainzino]

I have a 21 momentum 395ms it has a suburban Sw12del. I want to swap out for a tankless. Has anyone done this themselves?

I don't understand why you guys want to use propane that you have to pay for to heat water if you have a gas/electric water heater that you can use the RV parks electric to heat your water for free? It's one of the perks of paying for an RV site.