There are various common mistakes people make when dealing with frozen pipes and thawing frozen pipes.
Your boiler is making a funny noise and you shut it down, the noise may not be a big deal, call a plumber let them listen to the noise over the phone, in most cases we know if the noise is a big deal or not.
We had a woman with a squeaky circulator, she was so afraid of the noise she turned the boiler off and called a glorified handyman, who told her it was ok to leave the heat off till she could afford to call a plumber. Her entire home was destroyed, including her furniture, her pictures, computers, and boiler and water heater. The noise that she heard could have been fixed with a few little drops of oil.
Your boiler is not heating, the pipes on and around the boiler are cold, and you think I might as well turn the power to the boiler off and lower all the thermostats I'm not getting any heat anyway, NO!!!!!! DO NOT lower the thermostats and do not turn the power to the boiler off.
On many boilers, even though the boiler does not fire, the circulators still move the water through the heat pipes and the baseboard, moving water cannot freeze. Leave the boiler power on and turn the thermostats up, if you know how to put your zone valves on manual, open all of them so the water can circulate till the plumber comes to fix the boiler.
Dam! My pipe is frozen, I don't have water going to my upstairs sink, and I'll just have to wait for the pipe to thaw out. I will just turn the heat up and go to breakfast; maybe it will be thawed by the time I get back.
This may or may not be a good idea, it is possible the pipe just froze and did not break, and heating the house may thaw the pipe, no harm done, but what if the pipe broke? Then if the pipe thaws you would have a mess on your hands.
A better way to handle this is, turn the heat up, but before you leave your home, turn your main water valve off, this way if there is a leak it will just be the water in the pipes, and not full flow. If it does not thaw call a plumber, the longer it is left frozen the greater the risk of the pipe breaking.
I will use my trusty torch to thaw out my frozen pipes. Please don't even think of doing this, the odds of you starting a fire inside a closed wall is extremely high. If you are sure you know where the pipe is frozen, use a hair dryer to blow on the pipe.
My pipes froze, I can see the break, I just have to cut that section out and replace it. I can't tell you how many times at 3:00 in the morning, I tried to tell my self that very same lie. The odds are 99 to 1 you will have more then one break in the lines, and if you follow the fix the one I see logic you may find that you spent the whole day fixing a section of pipe with 50 couplings and you could have just pulled out and replaced the whole section all at once.
In areas like New York And others, the code requires a remote shut off switch to be installed at the top of the stairs, so that if there is a problem with the boiler and the basement is filled with smoke a person will be able to shut the boiler down with out having to go down the basement.
This is a great idea, I think all codes should require this, but I can't tell you how many times this switch has been turned off by mistake, someone thinking they are turning off the lights in the basement, but turn the boiler off, It is also required that the switch have a red plate that says boiler shut off on it, but even with this I have found this switch turned off. And yes if you call a plumber out and the only problem is someone turned the switch off, you still have to pay for a full hour.
A thawing machine, a great tool for the professional, but very dangerous, in the hands of the homeowner. Don't go out a buy one, call a professional; this thing can burn your house down, the cables can burn your carpet. This is an area where too much information can be dangerous, so I will stop now.
The bottom line, be prepared, don't leave anything to chance.
Information provided by Master Plumber.net
This article is only meant to give you general information on water heaters. Consult with a local plumbing professional to insure you are making the smartest and safest decision.