Water heater not working, trying to track down fault (FIXED)

[edy]

Thanks for the suggestions and help. I think I'll try getting the parts from a local store. Based on the RONA prices I see a wrench and a 1500 W 120 V element together is around $30-40 + tax. Then if I change that, forget the anode for now and maybe try to inspect it through the hole it might be easiest.

What happens if I don't change the anode? Will it just shorten the life of the element, or cause only faster corrosion of the tank itself, or both? If the anode is impossible to get out, or will cause more damage, I may opt to leave it alone and just have a plumber change the tank in a few years.

This tank is about $320, but the labor involved in changing it I would guest is more expensive.

https://www.homehardware.ca/en/rec/index.htm/Plumbing-Electrical/Plumbing/Waterworks/Water-Heaters/Electric/10-Gallon-120-Volt-1500-Watt-Electric-Water-Heater/_/N-ntjb3/R-I3284305

If the anode isn't too long and I can access it, I may be able to swap it out with this one:

https://www.homehardware.ca/en/rec/index.htm/Plumbing-Electrical/Plumbing/Waterworks/Water-Heaters/Parts/Gas-Electric-Water-Heater-Magnesium-Anode-Plug/_/N-2pqfZ67l/Ne-67n/Ntk-All_EN/R-I3285082?Ntt=water+heater+anode

Looks like they also have the wrench and element:

https://www.homehardware.ca/en/rec/index.htm/Plumbing-Electrical/Plumbing/Repair-Hookup/Water-Heaters/Elements/120-Volt-1500-Watt-Screw-In-Water-Heater-Element/_/N-2pqfZ67l/Ne-67n/Ntk-All_EN/R-I3285251?Ntt=water+heater+element

https://www.homehardware.ca/en/cat/search/_/N-2pqfZ67l/Ne-67n/Ntk-All_EN?Ntt=water+heater+wrench

Home Depot seems to have some options as well:

Element: https://www.homedepot.ca/en/home/p.water-htr-element-1500w120v.1000120198.html
Wrench: https://www.homedepot.ca/en/home/p.element-wrench.1000120184.html
Anode: https://www.homedepot.ca/en/home/p.42-inch---aluminum-anode-rod.1000150837.html

LOWES has them too, although a tad more expensive:

Wrench: https://www.lowes.ca/water-heaters/water-heater-socket-box-wrench-for-screw-in-element_g1453530.html?searchTerm=water-heater-wrench
Element: https://www.lowes.ca/water-heaters/water-heater-screw-element-1500w-120v_g1453598.html?searchTerm=water-heater-element
Anode: https://www.lowes.ca/water-heaters/whirlpool-9001829005-32-in-magnesium-anode-kit_g1453533.html?searchTerm=water-heater-anode

Is there any advantage to Magnesium vs. Aluminum anode? Is it an issue to cut them down to size if I can only find a longer one, or will it cause some problem? I assume I can just cut the anode to length once I see what my other anode length is if I manage to remove it.

[Ian.M]

Soluable Aluminium salts are bad for your health.
see https://www.atsdr.cdc.gov/phs/phs.asp?id=1076&tid=34
Always cook with cold water direct from a mains tap, preheating it in a kettle if you need hot water, never with water from a hot water system.  Do not drink water from a hot water system.

Aluminium anodes are safe and satisfactory in hard water areas, and last longer than magnesium anodes, but if you've got soft water or your water is acid, you should probably use a magnesium anode if the water is to be used for final rinsing of dishes and cooking utensils.     Magnesium anodes provide more protection to the tank and element but erode far more quickly and in some cases may require annual replacement.  If the water has very low dissolved solids, an aluminium anode may be ineffective.

Most anodes can be cut to length - as long as possible without hitting anything is good.   Personally, I'd pull the element and inspect the tank before buying parts.  Swapping the tank with one of the same make with ports in the same places isn't rocket science provided you've got physical access without ripping out drywall or support platforms etc. and isn't much harder than changing an element and an anode and getting everything you've disturbed watertight again.

[edy]

According to this sheet, we have hard water (123 mg/L of calcium carbonate or 8.63 grains/gallon):

https://www.vaughan.ca/services/residential/water/water_quality/General%20Documents/Water%20Facts111.pdf

So I guess aluminium should be ok.

[SeanB]

Standard wrench and standard element. Be sure to have a new seal for the element on hand, and be aware that the cheap wrenches can and do split on some older elements.  Hard water area probably the anode is still usable, they go fast in soft water, the hard water areas provide a nice film over the piping and element, which will have a nice brown crud film on it and will be missing a large chunk where it blew apart.

When you have it out, drain off the water out of the bottom, using a hosepipe as a syphon, and if not possible and you have a large wet and dry vacuum use it as well to get the crud ( which will look like tea) out of the tank.  When you have gotten the old element out, place a finger inside and feel for splits in the glass coat, and for any rust near there. Any splits, or big rust areas, time to buy a new tank ( buy the same identical model, much easier to put it in again as the mountings, piping and fittings will be in the same location and thus no plumbing) and swap it out.

I have done that before, got the same model tank, and just had to undo the old and put the new in. Then 2 years later I had to drain it to fix a leaking drain tap, by replacing it with a new one. Tank was fine on the inside, but the bottom was deep with sediment, despite having a 100 micron water filter feeding it. Swapped with a 10 micron one before filling it again, not going to have tea now in it.

The 40 year old gravity tank elsewhere also sprung a leak, so took it out, took to the manufacturer ( still in business, and local to me) and they refurbished it, new inner copper tank, new element and thermostat and new filling valve, and I hung it back a week later on the same bolts, connected the pipes to the tank with some new olives and nuts, connected power to it and filled it up again. Half the price of a new one, and a quarter the price of installing a pressure geyser. which likely would have popped all the old sweated joints as well.

[edy]

Success! I went down to Home Depot and picked up a water heater wrench, water heater element, and a few other bits. Total was under $30. I removed the old element, had a peek inside (see attached photos) and noticed my ANODE was covered in some crystalline material like lime scale (similar to the element).

I had a try at removing the anode as well, but no luck. I didn't have all the socket wrench tools and if I try to hammer on it up there, with no help or support, I'll probably break the pipes since this little water heater is not bolted down anywhere. Also I didn't want to risk damaging the head of the anode, so for now I'll wait until I have the proper tooling and help. I can always change the anode even with the tank mostly full.

As far as the element goes, I swapped the elements but noticed the new one didn't quite screw in easily. The threads looked the same, it went in a bit and got stuck. I cleaned the threads on the tank the best I could, lubed it up with some WD-40, tried again, gave it a bit more torque, it threaded some more, and worked it back and forth many times until I presume it cut it's way in to the point where the new element was flush as possible. I noticed quite a bit of dark greyish black stuff on my fingers as the WD-40 was I presume dissolving the crud and the metal components (tank and new element) were rubbing against each other.

For now I have hot water again. I hooked up the thermostat/regulator, flipped on the mains at the breaker panel and 1 hour later everything is fine. So for now I think I'll leave it. Will keep an eye on things though to make sure nothing is leaking.    Thanks guys for all the help!

[edy]

One more thing....

My water is REALLY REALLY HOT. I turned down the temperature as well, to see what happens. For safety, I cut the power to the tank over-night so I don't come back tomorrow morning to an exploded tank.

QUESTIONS:  I know the element works. Could the controller fail shorted? I do hear a "click" sound when I move the temperature knob around, so I figure it is the relay switching the element on and off as I pass the temperature with my set knob.

To test it, I will have to disengage the power to the temperature control and see whether I get continuity as I move the knob around. That will tell me if this thing ever shuts off properly at the higher temperature.

[Ian.M]

Its possible for the thermostat to fail shorted (by its contacts welding themselves together).  Depending on its mechanism, it may still 'click' as it passes through the setpoint. You need the tank hot at a temperature within the thermostat's range, then check it closes when you increase the setting to above the tank temperature and opens when you decrease it to below it.  As a final check, wire a bulb across the element and check it actually cycles as a thermostat may fail  'sticky' so it only switches if physically disturbed.

[helius]

Magnesium is more galvanically active than aluminum and so will sacrifice itself faster. There are also other reasons to prefer magnesium anodes to aluminum ones (actually they are usually a blend of zinc and aluminum).
http://www.waterheaterrescue.com/Longevity/water-heater-anodes.html

The picture you posted looks like an aluminum rod, as it has developed an alum coating (potassium aluminum sulfate hydrate). That makes it more difficult to remove.

[edy]

I wonder if the thermostat is faulty, could the element failure be linked? For example, say the thermostat failed first, stayed on until element overheated and burned out?

Or the other way, element shorts first maybe through some crud deposit, causes high amp across temp control switch fusing contacts short as well, then element short melts down secondarily causing open circuit across element again.

[SeanB]

Well, you tend to replace element and thermostat as a unit, as typically the one dies with the other, the element from thermal cycling every time it operates going from water temperature to 500C internally ( the element wire in the insulation gets red hot in operation), while the thermostat has contact erosion and wear on the pivot points of the expansion element.

New thermostat will fix that, and set the new one to 60C, makes water hot enough to kill the bacteria living in it, and saves a lot on electricity otherwise wasted heating it up.

Tip as well is to take that hot water outlet pipe and put some insulation on it, at least till it goes into the roof. You will see a noticeable drop in temperature in the cabinet there, and a drop in standby power usage. A little on the safety pipeline as well, just do not obstruct the test lever mechanism, will also reduce the heat loss. I use standard neoprene foam AC piping insulation, just buy 2m at the home improvement store, even the cheap stuff works, and a roll of gaffer tape to fix it on after slitting it.

[BurningTantalum]

The insulation available in my locality is really poor- very thin and not pre-slit and hugely expensive (compared to the UK/Europe)
I find that 'pool pasta' is at least twice as thick, rigid, can be mitred for corners and is about 1/4 the price at 'El Cheapo' shops. Plus it is pretty colours too.
And the magpies haven't ripped it up it in 9 years whilst the black stuff went in a few months.
BT

[DTJ]

The insulation available in my locality is really poor- very thin and not pre-slit and hugely expensive (compared to the UK/Europe)
I find that 'pool pasta' is at least twice as thick, rigid, can be mitred for corners and is about 1/4 the price at 'El Cheapo' shops. Plus it is pretty colours too.
And the magpies haven't ripped it up it in 9 years whilst the black stuff went in a few months.
BT

The pool noodles worked well on mine for many years. The UV killed it in the end. I should have painted it. Much cheaper and probably better than the real stuff.

[stj]

2 things to say.

1: it can be handy to connect a neon lamp (with inline resistor) to the element in order to see when it's on.

2: NEVER use WD40 for anything involving rubber seals.
infact never use WD40 for anything except rusty bolts on cars - just throw it away.
it's good at ruining things.
rubber gaskets, chip sockets, fiberglass pcb's - loads of things!! 

[edy]

Thanks for the advice.

Ok maybe I need to get a new thermostat then, just in case. I did turn it on again today, heated up the water and then went to check it.

I put the ohm-meter across the thermostat and moved the temperature set point up and down, heard a click and the meter went from showing 0 ohm (short) when I was set ABOVE the tank temperature, and then to infinite ohm (open) when I set the knob really low.

So it looks to be turning off.

The only problem is, when I set it to 60 C the water definitely is hotter than that. When I set it down to 45 C (the lowest marking) I will have to check. Perhaps it is just out of calibration. It still seems to be working but how can I trust it now?

I've turned off power to the tank, set the thermostat low so it is showing infinite resistance now (since the water is over the temperature set point) and will wait a few hours. If all goes ok, the tank water temperature should fall and the thermostat should flip to CLOSED mode since it will be below the set temperature.

[stj]

if the thermostat housing has limescale on it, it will act as a thermal insulator.

[edy]

The thermostat is clean, the tank is clean and it is sitting exactly where it was before. However, I don't trust the calibration on it. It is cycling on and off, but even at the lowest setting I am getting scorching hot water.

There is a disk that is supposed to pop in and out based on temperature... that toggles the power to the element. The thermostat setting knob adjusts a screw that essentially bends the disk more or less to make it "easier" for it to pop in/out. The lower the temperature setting, the more it pre-bends the disk so it pops open easier at a lower temperature.

If the housing of the thermostat, the metal backing or anything is off with it, it may change the forces required and the temperature calibration will be off. I'm not sure if I want to risk it. So better just to buy another one for now and hope that it solves the problem. I'll keep you posted!

[ADDED:]

I just checked the tank again, I touch the part of the tank where the thermostat is sitting. It does not feel hot. The pipe coming out supplying hot water is warm to touch, and I am getting scorching hot water from the tap. Why is the tank not hot at all? Maybe that is why the thermostat is not shutting off or seems to be "calibrated" off. It is never warming up enough to shut down the element. The tank is not heating up, yet the water is coming out hot and the pipes are hot, and the side of the tank isn't. 

[Paul Moir]

Just pop the cover on and let it sit a while until everything equalizes.  The hot water floats up to the top of the tank, which is where the hot water pipe draws from.  I'll bet the stratification is really bad on a 1500W unit since there won't be much convection going on.
Note that the threshold of pain for most people is right around 45 so it's hard to get a good idea of temperature there by feeling.  It's a very fine line between "That's nice and toasty hot" to "I feel like I'm being burnt.".

[edy]

I happen to have extra sensitive skin when it comes to heat. My wife always jokes about it... while she can hold on to a hot cup of coffee, I need to double-cup and add a sleeve. Perhaps I'm the one out of calibration. 

Anyways, I bought a new thermostat just to be sure, and hooked it up. I feel safer knowing I replaced it, just in case the other one was out of whack. I've set the new thermostat to the lowest setting and I want to see if I am maintaining a nice comfortable level of heat without it getting too hot over the next few hours. Then I know it is not over-shooting.

I let the water go for a few minutes and poured it on my hand continuously, it was not scalding and I was comfortable with full hot water only. I'll check in about 1-2 hours and see if it gets too hot. I should be able to pour a stream on my hand continuously without pain once the hot water runs for about 1 minute and stabilizes the temperature in the pipes.

If I am satisfied that it stays warm over a prolonged period and doesn't appear to getting hotter and hotter, I can rest peacefully leaving it to go overnight. Then I can check in the morning and slowly increase the heat over time. Otherwise I'll have to turn off the main breaker if I think it is running the element non-stop (which I think the other thermostat was doing because it wasn't tripping the set point properly or calibration was off as I thought I had it at the lowest setting but it was still hotter than I ever remember it).

[SeanB]

Yes those thermostats do drift with time as they wear the pivot points for the bimetal sensor and the contact points.

[edy]

So far so good.... I've had the power on for 2-3 hours now, testing out the water periodically.... It is maintaining a comfortably hot level. With the old thermostat it would have been scalding me already after 2 hours being on the lowest setting!

Now to leave it on for a few days and see how things go. I'm more confident now that the tank won't overheat.

I thought thermostats would fail by creating open circuit, not short out. Kind of a bad way to fail, no? If it fails open circuit no big deal.... cold water. But if you fail with a short it could explode your tank, pipes, etc... The reset is still there as a backup but what temperature does that pop out at to cut the mains off?

[EDIT: another few hours later, no problem. Looks like the old thermostat was also out of calibration. Now I wonder, did element fail independently or did a bad thermostat cause the element to burn out, and if so, why didn't the tank blow up from overheating before the element died, if that's what happened?]

[stj]

i had a stat weld shut, and the tank boiled!!!
it didnt damage anything.

[Paul Moir]

I thought thermostats would fail by creating open circuit, not short out. Kind of a bad way to fail, no? If it fails open circuit no big deal.... cold water. But if you fail with a short it could explode your tank, pipes, etc... The reset is still there as a backup but what temperature does that pop out at to cut the mains off?

That's why there's two redundancies:  the high limit cutout, which is the bimetallic thermodisk thing with the red switch, and the T+P valve.  That's why you never hear about explosions on unmodified tanks despite hundreds of millions of them being in the field.
High limit goes off somewhere around 80-90C.  I had to operate a tank at 95C once.