help - hot water tank leaking, no hot water

Our 2.5 yr old hot water tank is leaking from the top of the tank, and there is no hot water... Also, there is a little black box on the side of the tank with a green light that is blinking.
we had a power surge yesterday with lots of breakers tripped... not sure if that could have done something to the water tank.
any simple ideas?
I have a picture but can't figure out how to shrink it to post...

on further review....
the box that controls the boiler seems to have no power, so we've probably got a bigger problem than our water tank
we'll be calling the plumber now...
sorry for the interruption...
(~:

The plumber had to replace the control box on the boiler, which was fried, presumably by lighting. He wondered why the box got fried instead of any current first tripping the breaker. This is the second time this spring that we've had things fried from lightening - He thinks we have big electrical problems and I do too but we've not had much luck yet contacting an electrician. We'll keep trying, and he suggested calling our electric supplier, which we'll do. If any of you electricians have any ideas, bring 'em on.

You might want to consider either in-line or power panel mounted surge protection devices. Done on the power panel, you can protect most of the house from near misses. Nothing will protect from a direct hit except maybe lightening rods. All it takes, though, to get spikes on the power lines is a strike nearby (and that could be a mile or more). Similar to a surge suppression device for your computer, having one for the boiler with electronic components that are critical to household operations is a smart move. Also, many of the manufacturers offer some pretty significant insurance policies on anything damaged while connected to one (keep all your receipts, etc.).

One other thing to consider...spikes on the power line act as a cumulative effect - repeated smaller spikes can eventually produce similar damage as can one bigger spike. A surge suppressor/filter can minimize that damage and make the things last much longer.

As always, JADNashua, I appreciate the info
Now, can you make a knowledgeable electrician appear at my house? (~:

jadnashua said:

One other thing to consider...spikes on the power line act as a cumulative effect - repeated smaller spikes can eventually produce similar damage as can one bigger spike.

Click to expand...

That is only true of the surge protector devices themselves, as the MOVs can deteriorate when they absorb the energy. That is why the better surge protectors have indicators to show they are still functional and capable of absorbing further surges.

Any other electric or electronic devices have NO cumulative effect from surges. They either survive the surge or they don't. If they do survive, they are not degraded in any way.

dg

Your incoming telepone line has a 1000 Volt surge surpressor at the telco interface. This will normally prevent burnt wiring, but obviously will not prevent damaged telephones. Modern phones themselves have protective circuitry inside, but mainly to prevent fire in the event of power cross. Many years ago I was chief engineering technician for a telephone manufacturer.( Yes I have had a varied and some would say checkered career!) Florida was our nightmare. Whenever a severe lightning storm hit, our warranty line was lit up the nexr day! We did a lot of design work to help, but nothing really helps when lighting hits your house of the wires on your street.


As for power line surge protectors, they do help. They of course must have a clamping voltage which is higher than the peak of the AC power. The peak to peak voltage of 120 RMS is 290 volts. So typical MOV's if I recall are 340 and 370. So some spikes can get through which are capable of causing damage.

Some of the better systems also have noise filtration which can help. It depends on their design. I do disagree with the cumulative effects on electronic devices, though. The power input circuits - diodes, caps, etc. can be degraded by long-term spikes as well as the gates on transistors. Limiting that can be a big help.

Surge suppressors come in all sorts of designs and capabilities. For example, I have one on my home entertainment system that can absorb a max of 4800 joules. the el cheapo ones you can buy for $6.95 can absorb maybe 300 joules...a very big difference. The cheap ones don't do any filtering either. Not all surge suppressors rely on MOV's for protection, either. The response time with them is somewhat higher than say a gas discharge device.

Bottom line, a direct hit is usually not survivable into an electronic or electrical circuit. But, you can help protect yourself from near misses, or things like surges from local motor starts (think a/c, frig, big power tools, etc.) and smaller induced surges from outside of your house. Cheap insurance...