Water heater - tankless?

[charliez]

I replaced one of these in a gas/electric w/h. It was the same thread as a regular house w/h and i got one at lowes for about 12 bucks. So no, the above link is for a household size opening.

[andonso]

After looking around I found a couple ~20 gallon point of use water heaters.

One from Home Depot is $335.00 before taxes.

https://www.homedepot.com/p/Rheem-Pe...20U0/204318374

The space where the rv water heater was installed is approx. 24" wide x 20" deep x 14" high

The Rheem water heater dimension are 19.75D" x 25.25H" x 19.75W" so I would need to cut and remove a piece of plywood over the current water heater space and build a box with some insulation.

Also would probably need to find

A drain pan. There is a 20 inch at home depot that should fit

Water lines 15 to 24 inches to connect to the motorhome pex tubing.

T-valve with spigot to connect to the water inlet for draining the tank.

Another 20 gallon made by Reliance a subsidiary of A.O. Smith.

https://www.acehardware.com/departme...xoC8isQAvD_BwE

However if I choose to purchase either 20 gallon electric water heaters, I would be giving up running a water heater on gas.

Electric, gas and hybrid water 6 and 10 gallon rv water heaters have a faster recovery time. Where the 20 gallon electric recovery time from around one to two hours depending on the temp. of the source water and amount of insulation.

[Sundancer268]

Using the Camco hot rod is probably what killed the tank. It will cause a galvanic current when dissimilar metals are in contact with an electrolyte and water is an electrolyte. It might take several years but the damage is inevitable. The Suburban water heaters need the anode rod in the drain hole so a hot rod will also cause damage over the years to their tank also. Atwood does make a 10 gallon gas/electric water heater for RVs and that is the way I would go. In fact when my 6 gallon Suburban goes, it will be replaced with the Atwood 10 gallon unit.

[andonso]

I'm uncertain of the brand and if it's a Camco Hot Rod. There's no brand markings.

It's been installed in the 28 year old Atwood water heater for probably at least 20 years. From the looks of it and the thermostat it's an older one. The rod has 400 watts stamped on it.

I'm not certain what sort of metal the metal rod is made from. When I flushed the water heater around once a year their would be brown corrosion where I would use a bench grinder wire wheel to brush off and make it all shiny again.

But I think your correct the dissimilar metals didn't do the Atwood Aluminum tank any good. Possibly could survived longer without the heating rod or a different kind?


Atwood aluminum tanks don't require an anode rod as the Suburban steel ceramic lined tanks.

Suburban water heaters usually have a better prices than Atwoods which I'm told are sometimes preferred.

Anyway I'm looking at a 20 gallon Rheem electric as this motorhome stays connected to 120 Vac 30 amp service 24/7 and I'm replacing the Norcold N641 7.6 cu. fit. with a Whirlpool 10.7 cu. ft compressor frig.

The Norcold is giving me problems intermittently tuning off and not running for up to for several days. Sometimes happens after a heavy rain storm with high winds. but has happened other times when there was no rain/wind storm. Possibly needs a new PCB which run around $200.00 for this model.

I did look at a few 10 gallon rv water heaters, gas and hybrids on eBay but their cost is more than a Rheem 20 gallon water heater which will fit into the space of the Atwood.

Many if not most home water heater require 240 Vac. I'm on a 120 Vac 30 amp service. The Rheem 20 gallon runs off of 120 VAC and uses a 2000 watt element which equates to 16.xx or ~17 amps, which can be connected to a 20 amp circuit and breaker.

However to be on the side of safety I'm going to install for the Rheem water heater it's own dedicated 25 amp breaker using 10 ga wire. Some people run it from a 20 and 15 amp circuit and breaker, but I think a dedicated 25 amp using 10 ga wire would be better and I believe is recommended.

With the Atwood six gallon water heater, while taking showers I needed to be careful to only use hot water while rinsing. or would run out of hot water.

Dishes are the same, needed to be very conservative when and how washing and rinsing dishes. Usually ran out of hot water and needed to wait around an hour or more for the hot water to recover.

Anyway the RV basically all electric. I currently don't have any gas connected as it's only may be needed when the power goes out.

I do have have the Norcold and also a nearly new Atwood RV frig that can be connected to gas if power goes out and needed to preserve food.