Cap blown off top of electric water heater

Users who are viewing this thread

Viewer

Member
Messages
65
Reaction score
0
Points
6
Location
Australia
We noticed today that there was rust water stains on the top outside metal sides of our externally located electric hot water heater.

An inspection noted there is one small plastic cap on the top edge, and a larger one in the centre.

The centre cap had popped out and was sitting on the top. Where the cap went on, the water there was hot, but horribly brown, and it felt like bits of insulation came out as I cleaned it up.

I reattached the cap, and released the pressure on the relief valve. Water coming out was still hot, but rusty for the first couple of seconds, then clear. Just as I stopped on the pressure valve release, the top popped off again.

I cleaned it up, repeated the process. Clean water came out of the relief valve, and the top did not pop off.

Would all this indicate doom for the tank, and I am looking at replacement?

The tank is about 15 years old, and has been working flawlessly. Had we not noticed the staining, we would not have known there was a problem.

Many thanks, as usual.
 

DonL

Jack of all trades Master of one
Messages
5,205
Reaction score
72
Points
48
Location
Houston, TX
Welcome to Terry's forums.

What is your water Pressure ? Do you have a expansion tank ?


Good Luck on your project.
 

Reach4

Well-Known Member
Messages
38,749
Reaction score
4,400
Points
113
Location
IL
The rust and water could be from rain. Your heater may have some more life. Consider putting a roof or other cover over it.

I would flush the water heater. You can find directions on the web.
 

Viewer

Member
Messages
65
Reaction score
0
Points
6
Location
Australia
Hi,
Thanks for the replies.
It's definately not from the rain.
I don't know what the pressure is.
The top cap has blown off again, with more rusty water flowed out.
The water has remained hot all the time.
I will look up the draining of the tank.
 

Reach4

Well-Known Member
Messages
38,749
Reaction score
4,400
Points
113
Location
IL
If water is flowing out, the water heater is defective. Replace it. I thought the rusty water was just siting there.
 

Terry

The Plumbing Wizard
Staff member
Messages
29,946
Reaction score
3,460
Points
113
Location
Bothell, Washington
Website
terrylove.com
Don't drain the tank unless you have the power off to the unit.
If those elements aren't wet, they will burn out in seconds.

Fifteen years old, it may be that the T&P spring is old.............or that the entire tank is just gone.
I wouldn't spend time and money on a leaking 15 year old tank.

tp_2.jpg
 
Last edited:

DonL

Jack of all trades Master of one
Messages
5,205
Reaction score
72
Points
48
Location
Houston, TX
Don't drain the tank unless you have the power off to the unit.
If those elements aren't wet, they will burn out in seconds.

Fifteen years old, it may be that the T&P spring is old.............or that the entire tank is just gone.
I wouldn't spend time and money on a leaking 15 year old tank.


AMEN...
 

Viewer

Member
Messages
65
Reaction score
0
Points
6
Location
Australia
Thanks fellas...

Power is off, water to tank is off.
Naturally no water now coming off the top cap area.
I have purchased a new Dux 315L tank, and the plumber is coming this afternoon to install it.

As per the suggestions, not wasting time on the plumber just looking at it to tell me to replace it, and then get a an additional fee....15 years sounds like a good lifespan.

Whilst he is here, I will have him take a look at my other pressure tank problem.
https://terrylove.com/forums/index.php?threads/pressure-tank.58363/#post-430858

Thanks again all...
 

Viewer

Member
Messages
65
Reaction score
0
Points
6
Location
Australia
As far as I can ascertain, the cap fits in the centre of the tank,at the top, and is the entry and exit point for the anode, which is screwed into the tank, under the cap.
 

Jadnashua

Retired Defense Industry Engineer xxx
Messages
32,771
Reaction score
1,191
Points
113
Location
New England
Electric WH tend to last a bit longer than gas ones, but it's really luck of the draw how long one will last. Your local water quality, the temperature that you keep the tank, the use, and how cold your incoming water is all can make a difference. Most places seems to indicate anything over 7-years is on borrowed time. Expecting 15-years from any random one is probably asking too much, but anything's possible...some last much longer than that.
 

Viewer

Member
Messages
65
Reaction score
0
Points
6
Location
Australia
New tank in now, gee they take some time to release the old water when using a garden hose to empty them, but doing this, loosening some pipework etc, saved me some labour cost $'s. The plumber only had to cut one piece of the existing copper piping, and add on a bit extra to fit the new tank.......he used a special compression tool that looked bigger than a drill, and it had jaws at the end to fix/compress the two fittings together...he uses these rather than oxy, he said. Between us lifting the new tank from his vehicle,removing the old one, connecting and commission, took us an hour. It was good he physically double checked I had turned off the power at the meter box, nice to know he put importance on this.

The bottom screwed on plate to the old tank was well rusted out, and the foam at the bottom was showing through.It was still heavy when empty, due to the insulation inside being soaking wet.

I want to pull the old anoid from it and see it's condition, but need a bigger socket to do so...will borrow one soon.

Thanks for the help all...I appreciate it.
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks