will rv water pump operate a tankless water heater

[Fuzz]

Thinking about a tankless water heater..Does it require city pressure or will RV pump be enough when needed?

[noteven]

Fuzz an rv pump shuts off at 50psi (I think) which should be good for a tankless heater. Maybe the tankless manufacturer’s website has a min pressure spec?

[Fuzz]

Thank you.Seems that way just need  to do a little more digging..

[Daveh]

I am confused on this as well. Some people say their's work great while I read others who say they are either scalded or cold.I am interested but this conflicting info has scared me off. 

[Kirk W]

1 hour ago, Fuzz said:

Does it require city pressure or will RV pump be enough when needed?

They work fine while using the RV water pump and there are some that were designed for RV use.

1 hour ago, noteven said:

Fuzz an rv pump shuts off at 50psi (I think)

It just depends on the pump, and most of them can be adjusted for shutoff pressure. Typically they arrive set to shut off at anywhere from 45 - 50# static pressure. The actual water pressure while the pump is operating will vary depending on the amount of water in use. The water lines in the RV provide some restriction of flow which is what allows a pressure build up. 

[Chad Heiser]

I have a Truma on demand water heater in my RV.  It works just fine with the water pump or city water. 

Where a lot of RV on demand systems have an issue is with the ability to shut the water flow off at the shower nozzle (for water conservation).  This allows the cold and hot water to mix with no flow and messes with some on demand systems.  Some systems cannot handle this mix without flow and will either give scalding hot water or cold water when the nozzle is opened back up.  The Truma has a small accumulator tank and pump with the option for a return circulation line that allows the hot water to circulate in the line and remain at a constant temperature even when the nozzle is shut off.  In my opinion, it is the best on demand RV system available.  I have been very happy with it and will never go back to a typical tank style RV water heater.  It is very nice to be able to run loads of laundry and take a couple of showers without having to wait between each one for the water heater to recover enough to provide enough hot water for the next.

[dblr]

We had a Girard 2 and it worked fine with the pump, our manufacture upgraded us at a rally to the Truma which also works fine with the pump. Between the two we like the Truma the best.

[LindaH]

Our RV came with a tankless water heater and it works fine on the water pump...which is a good thing since we spend most of our time boondocking!  I really don't like our tankless water heater and would never have another one...but that's another story.

[Bill Joyce]

9 minutes ago, LindaH said:

I really don't like our tankless water heater and would never have another one...but that's another story.

I find that this is true of many of the cheaper tankless hot water heaters, but many people with the more expensive models (truma and precision Temp are examples that cost a lot more than the cheap ones) seem to be happy with them.  It costs money  to make models that behave well at different flow rates, so the cheaper ones are more simplistic.  

[Fuzz]

thanks all.. Appreciate all the comments.

[LindaH]

23 hours ago, Bill Joyce said:

I find that this is true of many of the cheaper tankless hot water heaters, but many people with the more expensive models (truma and precision Temp are examples that cost a lot more than the cheap ones) seem to be happy with them.  It costs money  to make models that behave well at different flow rates, so the cheaper ones are more simplistic.  

I've thought about replacing our tankless (Girard) with a regular water heater, but have no idea 1) whether there's enough room and 2) how much it would cost, if it was possible.

Any idea about how much it might cost to replace the Girard with something like a Truma or Precision Temp?

[Bill Joyce]

Girard is supposed to be a decent tankless, but I have no idea how to replace it.  I do know the fancy units cost $1K or so, plus installation.  If tankless was an option on your RV, I suspect you have the room to put a regular unit in.  You should be able to get some rough measurements and compare dimensions plus where the pipes attach.  The main advantage of tankless is unlimited hot water, not a good idea when you are not on full hookups.  

 

[Daveh]

1 hour ago, Bill Joyce said:

  The main advantage of tankless is unlimited hot water, not a good idea when you are not on full hookups.  

 

 

We have one of the 16 gallon water heaters and never really have running out as a big concern. I liked the idea of a tankless for less weight and less energy use. Are these not real benefits?

[Lou Schneider]

The problem with retrofitting a tankless water heater into an RV is the distance between the water heater and the showerhead.  The previous owner of my Sunnybrook trailer installed an Atwood tankless heater, it worked OK as long as you kept the water flowing.  If you tried to take a Navy shower, the short time it takes for the flame to ignite after you restart the water flow puts a slug of cold water into the line running to the shower and you'd get alternately frozen or scalded until the temperature stabilized.

A tankless heater located immediately adjacent to the shower will have less of these issues.

[dblr]

5 hours ago, LindaH said:

I've thought about replacing our tankless (Girard) with a regular water heater, but have no idea 1) whether there's enough room and 2) how much it would cost, if it was possible.

Any idea about how much it might cost to replace the Girard with something like a Truma or Precision Temp?

We were lucky and ours was done by the manufacture at a rally but the cost of the Truma I believe is around $1,800 then the labor, ours did fit in the original space with no issue. They replaced 8 units from the Girard to the Truma in 2 days with our factory warranty prepping and removing the original units then the Truma installer did the rest.

[LindaH]

18 hours ago, dblr said:

... the cost of the Truma I believe is around $1,800 then the labor, ...

Well, so much for that idea! 

[Lance A Lott]

I get a shot of cold water every time I take a Navy shower with a regular hot water heater and it only 2 feet from the valves. You quickly learn to point it at the wall when you use the trickle valve.