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Reason to undersize water heater elements?

Grnd93

The Dude
Joined
May 19, 2020
Member Number
236
Messages
734
Loc
Michigan
The last couple of days we had noticed a less than normal supply of hot water.
checked it out today, and sure enough, lower element had no continuity. Elements that were installed were 3500w/240VAC.
for shits and giggles I decided to check what my tank is supposed to have and find that it should have 4500W/240VAC elements.

i found some 4500w elements in the workshop that have been here since we moved in about a decade ago. They tested good, but had some corrosion on them. I figured for $20 I would just get new ones.

aside from someone not knowing any better, what would be a reason to undersize the elements?

i put the 4500w back in. Hopefully I don’t burn my house down.
 
lets you use smaller feed wire and breaker

it isn't more efficient, well you do get less line loss I guess but fuck man that's gotta be less than a percent

One thing I learned with the parts washer is that you need to find one with very very low 'watt density' with that filthy mineral scale and caustic soda filled water, you put in a stubby little water heater element instead of the 3' long element they come with and it scales up really fast then burns a hole in its casing.
Probably not really a concern in a water heater because it is pressurized so it doesn't boil on the element and relatively clean water so what little does boil won't scale too bad.
 
[486 said:
;n135366]lets you use smaller feed wire and breaker

it isn't more efficient, well you do get less line loss I guess but fuck man that's gotta be less than a percent

One thing I learned with the parts washer is that you need to find one with very very low 'watt density' with that filthy mineral scale and caustic soda filled water, you put in a stubby little water heater element instead of the 3' long element they come with and it scales up really fast then burns a hole in its casing.
Probably not really a concern in a water heater because it is pressurized so it doesn't boil on the element and relatively clean water so what little does boil won't scale too bad.

I guess I better make sure my wiring/breaker is sized properly/. This is an old house. Some wiring was updated from original, but not all.
 
really it's likely a case of getting to the hardware store then saying
"well fuck I didn't know they made different ones, no way in hell we're going home and coming back again, just grab the one in the middle of the range and lets go"

then after installing it remembering that they forgot to pick up the god damn carriage bolts and ending up back again anyways
 
Energy conservation.

Explain.

Where I'm sitting I don't see how smaller elements will conserve energy, other than your teenage daughter running out of hot water a little sooner when the smaller elements can't keep up.

1 watt for an hour costs the same as 60 watts for a minute and does the same amount of work.
 
Explain.

Where I'm sitting I don't see how smaller elements will conserve energy, other than your teenage daughter running out of hot water a little sooner when the smaller elements can't keep up.

1 watt for an hour costs the same as 60 watts for a minute and does the same amount of work.

I don't think it will either, but that doesn't mean that it wasn't the reason for the change.
 
Wait, I did just have a serious thought. Is the house set up for a generator? Maybe it was too small to run the water heater.
 
Wait, I did just have a serious thought. Is the house set up for a generator? Maybe it was too small to run the water heater.

That's a pretty valid reason, although it would be easier/better/cheaper to simply disconnect one of the two original elements, but that would be outside the scope of a harry homeowner.
 
The last couple of days we had noticed a less than normal supply of hot water.
checked it out today, and sure enough, lower element had no continuity. Elements that were installed were 3500w/240VAC.
for shits and giggles I decided to check what my tank is supposed to have and find that it should have 4500W/240VAC elements.

i found some 4500w elements in the workshop that have been here since we moved in about a decade ago. They tested good, but had some corrosion on them. I figured for $20 I would just get new ones.

aside from someone not knowing any better, what would be a reason to undersize the elements?

i put the 4500w back in. Hopefully I don’t burn my house down.

When I replaced the elements in my electric water heater at the shop, I had no idea what should be in the water heater. A friend gave me a couple and I installed them. Boom! Hot water. They may be undersized, they may be oversized but they work great.


Warning: when you buy a building that has been winterized, turn in the water and let the tank fill before you flip the breaker for the water heater.
 
[486 said:
;n135398]really it's likely a case of getting to the hardware store then saying
"well fuck I didn't know they made different ones, no way in hell we're going home and coming back again, just grab the one in the middle of the range and lets go"

then after installing it remembering that they forgot to pick up the god damn carriage bolts and ending up back again anyways

This is what I would tend to agree with and lean towards, but the fact that I has 2 correctly sized, seemingly gently used elements from the PO (my grandmother) in the basement has me a little puzzled/concerned.

I had hot water this morning and my house hasn't burned down from an electrical fire yet, so that's good news.
 
Maybe the answer is always the easiest one?
Maybe that was the only one that the last person could find.
 
Correct answer is to pitch the whole thing and put in a HPWH. With all the rebates available right now (some ending nov. 30th this year in our area) there is absolutely no reason not to. Local power company rebate of $700 +$300 federal make a 50 gallon unit almost free.

I converted in February this year and it's already saved me almost $200 in power.
 
That's a pretty valid reason, although it would be easier/better/cheaper to simply disconnect one of the two original elements, but that would be outside the scope of a harry homeowner.

Yeah, that's not how it works.


A normal water heater will only have 1 coil energized at a time
 
Yeah, that's not how it works.


A normal water heater will only have 1 coil energized at a time

Hmm....that's interesting. I wonder what the reason is. Two t-stats for two elements sounds more expensive than 1 t-stat for 1 element. Does give a bit of redundancy I suppose. I guess it's to more evenly heat the water in the tank without circulating it. I would have thought it would be reasonably consistent.

That's one of the things I like about this place: learning new things at unexpected times.

http://www.whirlpoolwaterheaters.com...ric-operation/
 
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