Instant or tankless water heater flue??

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New member
Sep 23, 2005
I have a new instant water heater it uses a 4 inch round flue. Can anyone direct me to a roof or side mounted vent to use with this? I contemplated running the flue pipe up to the Dometic roof vent and letting it flow out there. Any and all hints or suggestions are certainly welcome.

Gary RV_Wizard

Site Team
Feb 2, 2005
West Palm Beach, FL
Can't say that I've ever looked for an RV fitting like that.  Would a clothes dryer type vent fitting work?  Boat engine compartment ventilators should also come in that size and at least some will be a nicer finish (chrome) and more durable than a typical dryer vent.  I've seen them used a dryer vents on RVs with washer/dryers.

I would be surprised if there is room in the fridge vent tower for a 4 inch ppe - most of them are no larger than necessary for the fridge cooling fins.  I had trouble getting an antenna cable through the fridge vent of my current rig.
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