How to tell when water heater is at max?

[wopachop]

When using the electric heating element is there a way to tell when its reached max temp and shuts off? (besides trying to listen) I keep meaning the buy an instant meat thermometer. I suppose i could test the water temp coming out the faucet. But the way the tank is designed it seems the hot water that first comes out of the top of the tank does not represent the temp of the water lower in the tank.

I notice how quickly the shower water can go from hot to cold. Seems like the tank does a good job of not letting the incoming cold water mix with the hot water at the top of the tank. Thats why simply sticking my hand under the hot water can trick ya. I did that yesterday and sure enough the water turned cold in about half the time. Thought i had waited a decent amount of time for the water to heat up.

[Veebyes]

Don't know how long it takes from cold start on shore power & don't particularly care. Give it a half hour & it is warm enough for a shower.

Propane, give it 15 minutes or so & it is plenty warm.

If left hot overnight after being on propane then turned off, it is plenty warm in the morning for whatever hot water is needed.

[YC_1]

pianotuna wrote:
YC-1,

Did you upgrade the wiring when you went to 2000 watts? And the breaker?

Mine was already setup for 20 amps, breaker and all.

[wa8yxm]

Ok the element is 120 volts. You can get a 120 volt neon test light at most hardwares two short leads with probes. YOu may need to work some to access the heat ewlement but put lugs on the probes (the kind that slip over a screw) then loosen the conneciton screws and slip the connecters under and re-tighten, Recover the element but leave the light sticking out.
You will have to open the access panel to see the light

Like this one at Grainger

Or as an alternative you can use a Neon panel light again it needs to connect to the ELEMENT not the switch or anything else (well you could connect to the relay but it's right next to the element)

Like this one also at Grainger

I do not know why the links did not work . The one below works

The Google Search that found 'em

[pianotuna]

YC-1,

Did you upgrade the wiring when you went to 2000 watts? And the breaker?

[YC_1]

Find the schematic and post. An LED or regular 12 volt bulb could be placed to light up when the heating element is turned off just by connecting it to the return path of the T-stat snap disc.

When the T-stat removes voltage to the whatever device it controls, it could make the light go out, or on depending on how wired.

No indication of the actual temp, just an indication of the element being told to turn on. It could work on gas too.

A lighted switch if not already lit could be used. Light on = element off and water is hot for example.

[YC_1]

Just changed out our element for the 2000 watt one. Atwood 10 gallon heater.

Added mixer valve at water heater so water can only get to a max at each faucet.

Also changed out the T-stat and over temp T-stat as a kit. Water temps are now higher. Supposed to be 160 but I don't think it gets quite that high.

Chasing that cold to hot or hot to cold and chasing the shower controls was a pain. Nice long even showers now.

[Old-Biscuit]

Gdetrailer wrote:

Old-Biscuit wrote:

AquaHot, HydroHot, Oasis ------not the typical tank RV Water Heater

Attwood 1400W element
HERE
4779 BTU

Suburban 1440W element
HERE
4915 BTU

Gas 9000 BTU input, assuming say 60% efficiency 5400 BTU, most likely efficiency is closer to 70%-80% or about 6300 BTU-7200 BTU..

So, unless you have flunked math, gas IS faster, gas has a much quicker recovery and gas will sustain a longer draw..

And for the record, I ALSO HAD a Suburban 6gallon gas only, at one time, only took 10-15 minutes till it had scalding hot water..

RV water heaters unlike a sticks and bricks are typically set to 130-140 F temps, which is way above scalding point, it is intentional that they are set to high temps.. It allows you to heat a smaller amount of water bet yet draw for longer time.. Basically you will mix 1 part hot to 4 parts to cold to get a hot shower..

So if you use 1 gallon of water per minute and shower for 10 minutes you will have used 2 gallons of hot and 8 gallons of cold in that time frame.

Even if you used 1 to 1 that means a 6 gallon tank will get you a 6 minute shower..

Now if you DROP the amount of water used, you can now extend your time..

.5 gallon of water used per minute now means your shower can last 12 minutes even at a 1 to 1 mix..

I have personally never ever used anywhere near 1 to 1, basically slightly opening the hot water till it trickles then adding in much more cold water until I get a spray.. I am sure I am mixing 1 to 4 or 1 to 5.. And HAVE had no issues getting a darn hot 15 minute shower with hot water to spare..

Folks don't seem to understand that you cannot treat a RV like a sticks and bricks.. A sticks and bricks has a 40-50 gallon water heater..

Might read my 1st post
That info was covered
Atwood gas is 6 gal/8000btu & 10 gal/10,000btu
Suburban gas is 12,000btu (6,10, 12, 16 gal)

T-stat temp settings fr both brand listed

Also recovery rates were listed showing electric slowest, gas faster, both fastest

[DrewE]

It would not be a very difficult job (at least conceptually) to add a neon (or other 120V) pilot light in parallel with the water heater element.

[wa8yxm]

There is a very easy And I mean EASY (And safe) way to do it... IN fact a couple of them.. one I have lying in the next room (it is not YET for sale.. that happens much later and not on line)

The two are SURGE GUARD made by Southwire (Formerly TRC)
and the Progressive Industries EMS
We call these Surge Protectors but the top end units are so much more.

1: Like the elcheapo outlet strip "Surge Guards" they supress spikes...
2: They monitor voltage and if it goes too low (or high) they turn you off (See note)
3: they monitor current. (They just report it they don't consider it)

Note: Many are the RVers who plugged into a 30 amp outlet and found it fed with 240 volt instead of 120.. The top end units absolutly protect you if you do this (Lower priced units will not). (Lower priced units also do not monitor current)

So how does this help with the water heater?

With the WH off note the current amps) on a 50 amp note both legs
Now turn on the WH and note the *INCREASE* or agout 12-13 amps (on a 50 amp rig this will be in one leg.

When the increase goes away.. Water heater cut off

[Gdetrailer]

Old-Biscuit wrote:

AquaHot, HydroHot, Oasis ------not the typical tank RV Water Heater

Attwood 1400W element
HERE
4779 BTU

Suburban 1440W element
HERE
4915 BTU

Gas 9000 BTU input, assuming say 60% efficiency 5400 BTU, most likely efficiency is closer to 70%-80% or about 6300 BTU-7200 BTU..

So, unless you have flunked math, gas IS faster, gas has a much quicker recovery and gas will sustain a longer draw..

And for the record, I ALSO HAD a Suburban 6gallon gas only, at one time, only took 10-15 minutes till it had scalding hot water..

RV water heaters unlike a sticks and bricks are typically set to 130-140 F temps, which is way above scalding point, it is intentional that they are set to high temps.. It allows you to heat a smaller amount of water bet yet draw for longer time.. Basically you will mix 1 part hot to 4 parts to cold to get a hot shower..

So if you use 1 gallon of water per minute and shower for 10 minutes you will have used 2 gallons of hot and 8 gallons of cold in that time frame.

Even if you used 1 to 1 that means a 6 gallon tank will get you a 6 minute shower..

Now if you DROP the amount of water used, you can now extend your time..

.5 gallon of water used per minute now means your shower can last 12 minutes even at a 1 to 1 mix..

I have personally never ever used anywhere near 1 to 1, basically slightly opening the hot water till it trickles then adding in much more cold water until I get a spray.. I am sure I am mixing 1 to 4 or 1 to 5.. And HAVE had no issues getting a darn hot 15 minute shower with hot water to spare..

Folks don't seem to understand that you cannot treat a RV like a sticks and bricks.. A sticks and bricks has a 40-50 gallon water heater..

[opnspaces]

The lowest budget check I can think is to turn on the electric until you think it might be done. Then turn on the propane. If the water heater lights, it wasn't done heating. So turn off the propane and wait another 10-15 minutes and try again.

[2oldman]

schlep1967 wrote:
. But when hooked up to campground electric. Leave it on.

Probably the best idea, but there's that situation where someone else has just showered or you've just done the dishes.

[pianotuna]

Hi,

Stock water heater rods for RV's are 1400 watts. On my ten gallon unit, starting with water at the ambient temperature (66 f) it takes 90 minutes to the first cycle.

On propane that drops to about 30 minutes. If I use both electric and gas it takes about 20 minutes.

If I leave it on electric, the tank will cycle about every four hours and runs for about 15 minutes.

Since I pay for propane, and don't for electricity guess which one I use?

I find that turning it on first thing in the morning and having my breakfast--that there is enough warm water for a shower--and enough for dishwashing the rest of the day.

[schlep1967]

I've never worried about it. When I get water and electric hooked up I turn on the water heater. Not very often I am taking a shower in the first hour after arrival. From there on the water is always as hot as it is going to get.
There are some that refuse to let their water heater on all the time. I can understand that if you are using a generator or paying for the propane. But when hooked up to campground electric. Leave it on.