# Hot water heater blowing fuse



## Mike Swearingen

New water heater? Could be nothing more than a loose wire.
Cut the power and check all wiring. If that doesn't stop it, disconnect the wires on the elements and check them with an ohm meter for resistance. No resistance, probably a bad element. Replace it.
If THAT doesn't do it, replace the tstats with tstats with the exact same layout and number of screws. (Doesn't have to be same brand.) Exchange the wires from the old to the new tstats one at a time. Can't go wrong like that.
The parts should be under warranty.
Good Luck!
Mike


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## Alan

Could be a number of things listed above. Most common for a bad t-stat is for the t-stat to not be touching the tank, therefore not reading the proper temperature, and the elements are pulling more juice to get the water much much hotter than it needs to be. You would notice really hot water in this scenario.

Obviously also leaks can cause shorts and blown breakers. If you pull the covers and see any signs of wetness it may be time for a new heater.


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## kb3ca

Is it blowing a fuse or tripping the circuit breaker? If it's the circuit breaker and it's old it may have gone "soft" and should be replaced to stop the nuisance tripping.


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## Cattman

*Fuse*

I have a double pole 30 amp breaker that feeds to a double 30 amp fuse shutoff box that is located adjacent to the heater in the basement. It is one of these 30 amp screw in fuses that is blowing. THe previous heater has zero problems blowing fuses or the breaker.


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## Thurman

"New" water heater. The old one worked fine, until-- The new heater may have elements rated higher than the old one, this drawing more amps. You have a 30-amp double pole breaker feeding a box with two 30-amp screw-in fuses? You may want to have an electrician look at/rate your wiring to see if you might by-pass the fuses and use only the breaker set-up. David


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## COLDIRON

I agree with Thurman, I would have the wiring checked and if its the proper size and condition I would eliminate the two 30 amp fuses they are just a nuisance.


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## mykol_j

New guy here. I've been reading your posts, thanks for helping out your fellow DIYers! 

I had a thermostat that fried itself and took the upper element with it. Prior to that, the fuse (on the tank, not the breaker on the house) would pop occasionally, maybe half-dozen times in the life of its six years, usually around the time of the first cold-snap of the season. 

I replaced the thermostat along with the element and a wire that that melted (all with the guidance of my master-certified-plumber neighbor). Now the fuse pops every day. I reset it, it makes a tank of hot water, we shower, the next day I reset the fuse, rinse-wash-repeat... 

I replaced the thermostat with another one, and it does the same thing. I saw the post about the thermostat not being flush with the tank and made sure it was tight up against it -- we have the similar symptoms of the water being very hot after resetting it -- before popping again. I also confirmed the wiring diagram is correct and that they're tight. I know I got the right element for the wattage. 

I called an electrician that said he could come and check the wires for voltage, and charge me a service call, but otherwise said there's not much he could do. I thanked him for being honest... 

Any other ideas? Could the element be sort-of-bad? (working, but drawing too much juice?) 

Thanks! Mike


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## TarheelTerp

mykol_j said:


> I had a thermostat that fried itself and took the upper element with it. Prior to that, the fuse (on the tank, not the breaker on the house) would pop occasionally, *maybe half-dozen times in the life of its six years,* usually around the time of the first cold-snap of the season. ... Any other ideas?


Has that tank EVER been flushed?
What sort of water quality do you have? Hard? On a well?

I haven't viewed these and not saying it's the problem... but it's a start:
http://www.youtube.com/watch?v=bjOK7znaMy4
http://www.youtube.com/watch?v=qkAnBZigOq0&feature=related

ps: you can start your own threads and should with a new question like this.


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## Hardway

Are you using time delayed fuses?
You should be using 10-2 w G
Check all your connections.
I am sure the Fuse box is there because it is not in line of sight of the main panel.
I am not sure that you need a fuse or a switch can be used.
The new heater may be pulling higher amps on start up and weaken the fuses and then they blow. 

I have an electrical water heater in the barn up north. Sitting right next to the well pump. Both are on 30 amp breakers. The water heater disconnect is breaker located near the heater. The well pump is on a switch. There is no reason other then that is how I wired it. They were wired at different times over a year or so, both passed final inspection. 
My air compressor is located about 10’ from the main panel it is on a 30 amp breaker, it has a double pole 30 amp rated switch to turn off power, when not in use. I am sure a master electrician will post weather you can do away with the fuse block.

My postings are for discussion purpose only and should be verified by another independent source.


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## mykol_j

Should I have started a new thread?

Oh well, 
to answer Tarheel:
No it hasn't been flushed -- water is hard, on a well, but it's on a water softener -- been since day 1. I had to empty it to replace the element and no deposits came out (I know it's not the same as flushing it). I guess it's worth a try. I can kinda see how deposits on sides could interfere with a temperature reading, but the tank is only six years old.

Hardway:
I don't really know what you're talking about. It's on a standard 30 amp breaker on the house, it's the only thing on that breaker. Time delayed? No, nothing non-standard. The fuse (maybe it's the wrong term) I'm talking about is the red reset switch in the thermostat (http://inspectapedia.com/plumbing/Electric_Hot_Water4.htm) -- again, standard -- as far as I know you'd have to go out of your way to deviate from that hardware...

I've checked and rechecked the connections. I even re-did them 100% when I installed a second thermostat.

Sorry if this should have been on a different thread, but I thought it was related...


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## Hardway

mykol_j said:


> Should I have started a new thread?
> 
> Oh well,
> to answer Tarheel:
> No it hasn't been flushed -- water is hard, on a well, but it's on a water softener -- been since day 1. I had to empty it to replace the element and no deposits came out (I know it's not the same as flushing it). I guess it's worth a try. I can kinda see how deposits on sides could interfere with a temperature reading, but the tank is only six years old.
> 
> Hardway:
> I don't really know what you're talking about. It's on a standard 30 amp breaker on the house, it's the only thing on that breaker. Time delayed? No, nothing non-standard. The fuse (maybe it's the wrong term) I'm talking about is the red reset switch in the thermostat (http://inspectapedia.com/plumbing/Electric_Hot_Water4.htm) -- again, standard -- as far as I know you'd have to go out of your way to deviate from that hardware...
> 
> I've checked and rechecked the connections. I even re-did them 100% when I installed a second thermostat.
> 
> Sorry if this should have been on a different thread, but I thought it was related...


My new electric hot water heater is blowing a 30 amp fuse in a random pattern every 2-4 weeks. What could be causing this? Bad Element? 

Hardway:
I don't really know what you're talking about. It's on a standard 30 amp breaker on the house, it's the only thing on that breaker. Time delayed? No, nothing non-standard. The fuse (maybe it's the wrong term) I'm talking about is the red reset switch in the thermostat (http://inspectapedia.com/plumbing/Electric_Hot_Water4.htm) -- again, standard -- as far as I know you'd have to go out of your way to deviate from that hardware...


“Hardway:
I don't really know what you're talking about.” 
mykol_j nor should you, you jumped in the middle of a thread that is about a new water, not a 6 year old heater. :whistling2:


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## Hardway

mykol_j said:


> New guy here. I've been reading your posts, thanks for helping out your fellow DIYers!
> 
> I had a thermostat that fried itself and took the upper element with it. Prior to that, the fuse (on the tank, not the breaker on the house) would pop occasionally, maybe half-dozen times in the life of its six years, usually around the time of the first cold-snap of the season.
> 
> I replaced the thermostat along with the element and a wire that that melted (all with the guidance of my master-certified-plumber neighbor). Now the fuse pops every day. I reset it, it makes a tank of hot water, we shower, the next day I reset the fuse, rinse-wash-repeat...
> 
> I replaced the thermostat with another one, and it does the same thing. I saw the post about the thermostat not being flush with the tank and made sure it was tight up against it -- we have the similar symptoms of the water being very hot after resetting it -- before popping again. I also confirmed the wiring diagram is correct and that they're tight. I know I got the right element for the wattage.
> 
> I called an electrician that said he could come and check the wires for voltage, and charge me a service call, but otherwise said there's not much he could do. I thanked him for being honest...
> 
> Any other ideas? Could the element be sort-of-bad? (working, but drawing too much juice?)
> 
> Thanks! Mike


mykol_j aka Mike

The red button reset button or, high limit known as the Energy Cut Off or, ECO

Rather then try and explain in bits and pieces, read the following link. Post after reading if you need anymore help, or how you make out. 

http://411plumb.com/electric-water-heater-red-reset-button-tripping-troubleshooting-guide

Hardway


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## biggles

it's the new heater and the old screw ins go to a 35A fuse if you can or remove the screw ins and bring the T wires up to the Ls from the breaker within the disconnect next to the heater or replace with a non fused disconnect.the cycling of the unit element is taking out the one fuse.if it was a basd element it would always short or do both...


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## TarheelTerp

biggles said:


> it's the new heater and the old screw ins go to a 35A fuse if you can or remove the screw ins and bring the T wires up to the Ls from the breaker within the disconnect next to the heater or replace with a non fused disconnect.the cycling of the unit element is taking out the one fuse.if it was a basd element it would always short or do both...


can you say that in english?


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## biggles

you don't know the difference between the T wires and L wires within a fused disconnect....:huh:


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## Cincyken

Cattman said:


> My new electric hot water heater is blowing a 30 amp fuse in a random pattern every 2-4 weeks. What could be causing this? Bad Element?


In my case and possibly others, i think it is a problem with fuse box, the fuse holder specifically. I think the base contact is not meeting flush - making contact on a corner of the fuse, and causing it to heat up, failing the ‘slow blow’ function of the fuse ( spring tension pulling up the base contact). See photo of base markings ( circled), and internal discoloration of the ceramic (arrow)). Check your box center contact and see if it is level and make sure the fuse is snug in place.


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## Cincyken

Cattman said:


> My new electric hot water heater is blowing a 30 amp fuse in a random pattern every 2-4 weeks. What could be causing this? Bad Element?


In my case and possibly others, i think it is a problem with fuse box, the fuse holder specifically. I think the base contact is not meeting flush - making contact on a corner of the fuse, and causing it to heat up, failing the ‘slow blow’ function of the fuse ( spring tension pulling up the base contact). See photo of base markings ( circled), and internal discoloration of the ceramic (arrow)). Check your box center contact and see if it is level and make sure the fuse is snug in place.


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