Pros and Cons of Tankless water heaters in RV

valhalla360 wrote:


You don't need much 135F water to mix into 90F tank water to get to 110F at the shower head. That means a 6-10gal water heater can easily provide 30-60gal of hot water. Of course when in Florida with 90F temps, I generally don't feel the need for a really hot shower. In fact just running the cold water which will be around 90F is fine. (Even down around 80F, it won't bother us much).

When camping in 30-40F, that's when a piping hot shower at 110-115F feels really good but now you are asking the hot water heater to bring the water temp up by 80-90 degrees. A tank based heater will be limited in duration but it can get the water up to temperature. Most of the smaller tankless units struggle to get the water that hot on a consistent basis.

Correct!

RV tankless water heater manufacturers do not publish the full specs unlike tankless water heaters designed for sticks and bricks.

Sticks and bricks tankless water heaters typically are able to maintain 45F rise in the temp over the incoming water temp at the rated flow rate often up to 5 GPM.

Incoming water temp of 45F plus 45F rise at 1 GPM for a RV tankless giving you 90F water is going to be a pretty chilly shower.

Sticks and bricks tankless water heaters also feature a much higher BTU burner, often 160,000 BTU compared to RV tankless of 40,000 BTU to 60,000 BTU which is going to limit a RV tankless water heaters useful operating range.