Water heater failure

[Jsmallberries]

Trying to help an elderly neighbor.

All 40 gallon natural gas water heaters. Central Florida. We have hard water, but they have a whole house softener . Water pressure in is 75 PSI. There are no expansion tanks installed in my area, so it's safe to assume there is an open system here. The original builder did install a pressure valve at exterior hose bib, (see pic) not sure if they help or work anyway. Theirs is missing. She did have the water temp set to 160. Not sure about previous settings. TPR was determined to be good

Original water heater failed after 11 years, second one installed in 2011, failed in 2015. Third one failed in 2020. The first failure, not unusual, but mine lasted 18 years, Second one, unknown cause? Her husband took care of these things and he passed away. Third and most recent, State WH , split at the back, (see photo.)

The same company installed the 2011 replacement, so the 2015 was a warranty no cost replacement, but they claim to have no records as to why it was replaced in 2011.

Any ideas about what might be behind this high failure rate. And don't these things explode if the tank is opens while under pressure, seem to remember high velocity explosions used to occur from time to time

 

[Terry]

Just because there is no expansion tank installed now, that doesn't mean that their water meter wasn't replaced at some point with one that had a check valve. When my water meter was replaced on my Redmond home, the water heater failed shortly afterwards.
Having the water heater at 160 is a bit much too. Can you call the water department and ask what they are using there at the meter?
The water heater should have come with a T&P, which is for relieving pressure, but that's about all it does.

The water heater should have a serial number which will date it. The supply lines look new but the water heater looks old to me.

 

[Sponsor]

 

[Jsmallberries]

Thanks Terry

A new TPR was installed, what they are missing is the pressure valve like the one in the picture. Again not sure that matters.

Would the local water municipality really replace an open meter with one that has a check valve and not tell the home owner??

Will be calling them asap, as I recently replaced mine. Any recommendations on a expansion tank for this system?

one more thing,I've lived here for 20 years and have never seen one expansion tank installed

 

[Terry]

They may or may not mention it. They have been changing out meters for years though to prevent cross contamination. Or they may have mentioned it with the billing and it went unread.
I use a 2.2 gallon for up to 50 gallons. I don't think brand matters.

I don't see a pressure reducer, only a pressure relief. Those are set for 150 PSI for most and some for 125 PSI

 

[hj]

Heaters only "explode" when in a superheated condition, which is seldom the case unless they heater "ran wild". One of my previous heaters also expanded like that, usually from corrosion inside the metal covering.

 

[Fitter30]

How are these tanks failing? Water heater can only explode if they run dry, burner is on, tank turns red hot and water is introduced that flashes into steam and expands 1700 times so fast it makes a bomb.

 

[Jsmallberries]

The water heater was installed in 2015, on the plate it listed manufacture date of 2014, so not an old tank

I called the local water utility company, the department for technical questions, didn't know what a check valve was. I was put on hold, and when they came back they advised me it has a double check valve. Told me it has a back up check valve in case the first one fails. Asked him about the expansion tank, didn't have a clue. The licensed plumbers installing the new water heater for my neighbor didn't know what I was talking about?

1) So would that set up, with no expansion tank cause the failure?
2) Assuming it was working, wouldn't the TPR valve release any built up pressure, isn't that what it is for?
3) Wouldn't the pressure valve on the exterior hose bib release excess pressure?

 

[Phog]

2) Assuming it was working, wouldn't the TPR valve release any built up pressure, isn't that what it is for?

You can get upward pressure spikes without ever reaching the threshold to open the TPR. The up and down cycling of the pressure will fatigue the metal and accelerate aging, eventually leading to premature failure. The expansion tank on the other hand keeps the pressure (relatively) constant, avoiding the pressure cycles and extending tank life.

 

[Terry]

Only an expansion tank would be of any help.
By code you're only allowed up to 80 PSI in a home. Those relief valves are set for 150 PSI and are no help to you at all. They are only there so nobody gets killed by a tank explosion.

The max pressure allowed in a home is 80 PSI

 

[Jadnashua]

For the record, many (all?) public water utility companies either have or will be installing a check valve on their system as recommended by the feds, eventually. To make this a feasible task, they're doing it in batches, and you may not know when it happens. For this reason, it's probably prudent to be ready to install, or to install an expansion tank on your system. Far less expensive than replacing a water heater or cartridges on faucets as the pressure changes above design which can cause early failure.

Where I live, they're required on any WH installation, whether there's a check valve or not.

 

[Jsmallberries]

Good to know, thanks.

Based on the photo, it's installed on the cold water side. does it need to be within a certain distance from the tank?

And yet, I've never seen one installed here in west central Florida and I was in a job that put me in over a thousand homes over time. Tanks don't appear to be failing at an unusual rate, except for hers?

 

[Reach4]

Wouldn't the pressure valve on the exterior hose bib release excess pressure?

There exist such devices. They do waste some clean water, so the expansion tanks are preferred. Do houses in that neighborhood have such a device that dribbles water occasionally when no outside water is being used?

Close is not a problem. Some brands (at least Therm-X-trol) call for the tank to hang down. Others want it vertical, up or down. Some want it supported if not vertical (Watts).

 

[Jsmallberries]

Yeah they do, or used to. Probably not functional after 20 years of hard water. I will be adding an expansion tank.

Interesting that the "licensed " plumbers didn't have clue about it

 

[Reach4]

I have a term for you: "thermal expansion relief valve"
http://media.wattswater.com/PG-ThermExpansion.pdf


The Governor™ 80M2, covered in that document, appears to be no longer be available. It would release excess pressure into the toilet tank.

Some areas may forbid or discourage these thermal expansion relief valves because they waste fresh water.

 

[Jsmallberries]

Thanks for that info,
It's most likely then, without an expansion tank, and someone had removed the thermal expansion valve and the meter check valve installed, has caused her premature tank failures

We offer several alternatives for pressure relief. While unlike an expansion tank such products do not prevent against loss of water, they do limit high pressure and prevent issues associated with thermal expansion.Products include:The 530C calibrated pressure relief valve.The LFBRVM1 combination ball valve and relief valve

And sharkbite has this one below

 

[Jsmallberries]

With the current thermal expansion relief valve that is installed, to test if it works I backed it out to 50 PSI and no water drips out. Assuming since pressure is 75 PSI, it should open up under that, especially at 50 PSI setting.

Is that a safe assumption?

also, it is a simple threaded device, however, it's too close to the wall to turn. Typical install without thought for future servicing.

Will need to sweat it out. Will add back a 45 degree fitting to make it accessible

 

[Jsmallberries]

Outdoor electric smoker, I guess I can connect one somewhere in the water supply but not sure how it would solve the thermal expansion issue

 

[Jadnashua]

Depending on where you live, dumping potable water unnecessarily just seems like a societal major problem when a suitable solution exists. It's a similar situation in a place with long hot water supply lines where you need to dump at least a few gallons of water each time you really want hot water. Where water is cheap and plentiful, it's more of a convenience. But even there, (at least where I live) there are times when the supplies get a bit low, and they ask people to conserve.

If you happen to live where carpenter ants or termites are a problem, dumping water is also asking for problems. They just love damp earth.

 

[Jsmallberries]

Good points JD, going with the expansion tank.

As for the wasting of potable water while waiting for the hot water to get there, what's the best solution? Central Florida, slab on grade, plumbing under slab, natural gas supplied water heater.

 

[Jadnashua]

There are numerous hot water recirculation systems out there, and you could roll your own, but with lines (especially hot?) under the slab where you're unlikely to be able to insulate them, the energy cost may not make it worth it. It works well, and may not be a huge energy hit IF you can minimize heat loss from insulating the pipes. May still be worthwhile in the desert SW where water is so dear.

But, a demand system that you activate when needed rather than run (most) of the time could still save water. You could use motion sensors, or a remote button to turn on recirculation, but that type of control means you'd have to wait for the pump to bring the hot water there. Depending on the pump, the size of the pipes, and their length, that could take a few minutes. Big pumps can literally erode the pipes out from the insides over time and can create water flow noises while running. The unit I have has a quite small pump that maybe runs 3-5 minutes per hour, but all of my lines are insulated. It's on a timer, so it's off overnight. If I were regularly out of the house for a period during the day, it would be turned off then, too. The first one I had lasted about 16-years, and I was unable to get the needed repair part, so I bought a new one from a bigger name that I hope will be around if, and when it needs servicing.