How water in home is suddenly VERY hot
 

We moved into a new-used home about a year ago. 6 months ago our water no
longer got very hot. We had a plumber come out and install a new element in
our heater. (I believe there are 2 and he replaced 1). 2 days ago our hot
water got VERY hot. It will cause a burn if you hold hand under it now. Is
this indicative of a failing element? The hot water heater is probably 20
years old...probably time for new one? Or should we check on replacing the
other element?

Sounds like the thermostat on the water heater needs replacement, it is
not shutting down the elements when it is reaching temperature. I would
say with a 20 year old water heater you are definetly on borrowed time.
Don't waste the money on fixing it, put it towards a new heater

wekiva wrote:

We moved into a new-used home about a year ago. 6 months ago our water no
longer got very hot. We had a plumber come out and install a new element in
our heater. (I believe there are 2 and he replaced 1). 2 days ago our hot
water got VERY hot. It will cause a burn if you hold hand under it now. Is
this indicative of a failing element? The hot water heater is probably 20
years old...probably time for new one? Or should we check on replacing the
other element?


Besides thermostat problems, a failed element can cause overheating.
If the element shorts to the (grounded) sheath internally, high
currents can flow which the thermostat cannot interrupt.

With the power turned off, take the wires off the element terminals
and use Ohmmeter to check from each terminal to ground. A good
element will read greater than ~10,000 Ohms to ground.

Jim

I've seen it stated many times by those apparently expert, certainly
more so than I, that with electric heaters, the tank can last waaaaay
longer than the electricals.

Ask around locally as to how long heaters normally last with your water
chemistry. Ask the plumber how the tank innards looked when he pulled
the element.

What I'd do:
1) get a replacement anode rod, pull the existing one, and replace.
2) ditto with heating elements and t-stat. You may need wrench to fit
element. And proper sealant. Lotsa supply houses all over.

Sediment cleaning is good, too.

That might buy you 10 years more. If you want better insulation, have
no problem financing it now, and have suspicions about heater from
above, go for a new one. And ... much better yet: gas. Price/BTU
typically 1/4 of electrical power.

HTH,
J