I think that the discussions are healthy as it often seems that the OPs in many of these threads start out completely oblivious to the real nature of tankless LP water heaters as might be used in FGRV's
. (For this post I am setting aside the issue of electric tankless heaters as they are designed for a different purpose.)
In most discussions it seems that the small size and low price of certain tankless water heaters trumps considering the conventional RV water heater, and that real or imagined advantages, such as weight
and fuel savings, are thrown up to cloud
For those that really want to save fuel & weight, there are tankless water heaters in the $500 range, that can do the job, weigh less than a conventional water heater, allege to save fuel & water, and sound like a F16 in afterburner when fired off.
And there are the much less expensive tankless units that, are clearly labeled for outside or well ventilated space use only, are usually known to have variations in temperature based on water flow rates, and really have very few FGRV application users.
However, as conservation of resources seems to be a primary advantage, can anyone present any daily consumption and $$$ figures that show how much fuel is actually saved in a typical FGRV application?
Our hi-tech answer to LP conservation, using a conventional water heater, is simply that we turn it off when it's not needed. Two heating cycles a day seem to take care of our entire needs for hot water, adding daily showers for two might require one additional cycle. And, by planning ahead about 15 minutes, we can always have hot water when we need it.
One would suppose if a user was spending 18 or more hours a day inside an FGRV, had an unlimited source of water, as well as a way to dispose of it and/or was in a situation where replenishing LP fuel were all issues, that saving a modicum amount of LP could be an advantage.
But, based on comments about temperature variation due to flow rate changes, I would guess that more fuel & water may actually be used adjusting temp and waiting for temps to stabilize.
However, for the majority on this site that don't fit any/all of those criteria, I just don't think that the many disadvantages of those tankless water heaters being discussed come close to offsetting any advantages.
If anyone can present some documented proof otherwise it would be welcomed by many.
Keep in mind, that if someone starts a thread that others have opinions about, such as tankless water heaters, towing over mfgs. limits, maximum speed on SP tires
systems and just about any other aspect of RVing, that they may get replies that don't agree with or are in conflict with others opinions and, heaven forbid, might actually drift off-topic. One can't expect to be able to control replies, or even the direction of discussion, it's the nature of this beast.....
As this site is primarily intended for those with Molded Fiberglass Travel Trailers, the replies to questions should be expected to reflect their needs and issues. For those with other agendas & interests, there are other sites that may be more understanding of different needs and beliefs.
And last; Disagreement & differing opinions do not