Keep the water heater turned on. Protect the pipes going to it and coming from it. An attic would usually get some heat flowing up through the ceiling below. It may get cold but would rarely freeze if the rooms below are heated.
If the issue is isolated to the water heater, turn off the power. Next, turn off the gas and water shutoff valves and disconnect the unit. Relocate it to a warm room or use a space heater if you can't move the water heater away from a chilly area. Once the unit starts warming up, the ice should melt.
Do NOT turn the water off unless there's an actual leak. The correct thing to do is to run the water 24/7 until temperatures rise.
Insulate the Tank and Exposed Pipes
You should also insulate cold water pipes if there's a threat of the home freezing. For older or less insulated water heaters, consider adding a water heater blanket or additional insulation. This can help retain heat and reduce energy consumption.
Frozen pipes can cause serious water damage to your home. The warm water your heater produces will continue circulating your system and prevent the leaks, cracks, and burst pipes that freezing can cause. Leave your water heater on to avoid frozen pipes and accompanying damage to your property.
Open a Hot Water Valve
By opening faucets, water will have a path to flow as the pipe unfreezes. Steam will also need a place to go as heat is applied. As the pipe thaws, running water will accelerate the defrosting process. Therefore, it's beneficial to have faucets running until the pipe is completely thawed.
Pipes can still burst in freezing temperatures even after you turn off your home's water. The pipes will still have water inside them, which means the water may freeze and potentially burst your pipes.
Water heaters aren't usually the first part of your plumbing system you think of when you're preparing your home for the winter. In reality, though, it is just as important to winterize your water heater as it is the rest of your home, especially if your area is prone to cold weather snaps like in North Texas.
Ewald suggests you also leave the hot water drip, and keep the cabinets open under the sinks. If your pipes still freeze and you don't have the know-how to thaw them yourself, Ewald says to call a plumber right away. Once the pipes thaw on their own, this is when they typically crack and burst, flooding your home.
Before you start draining the tank, you'll want to shut off the cold water supply. The supply valve connects your water heater with the main water line.
Most tankless water heaters have built-in freeze protection that works in temperatures down to -22 degrees F. Don't buy a tankless water heater without this feature, especially if the only alternative is to install it outside. Different brands use different freeze-prevention methods.
There are a few situations where draining your water heater is a good precaution to ensure the unit can't freeze, such as if your power ever goes out during the winter when the outside temperature is below freezing.
Thawing Frozen Pipes
While you wait, reduce water pressure by opening all the faucets inside the home one-quarter turn. Water will begin to trickle out, helping the ice to thaw. Remember to close all faucets after full water pressure is restored.
Turn the unit's fan setting to “ON” via your thermostat. This helps thaw the coils by moving warm air through the system. Melting may take 60-90 minutes, depending on the level of accumulated ice, so be patient. Warning: Never use sharp tools to chip off ice or boil water to melt it faster.
Frozen pipes can cut off your home's water supply and cause damaging leaks. In many cases, the help of a plumber is needed to resolve the problem. To prevent further damage, it is generally recommended that you turn off your main water supply valve and your water heater until repairs have been made.
Your Pipes Could Freeze and Burst
The heat in your home helps your pipes stay warm. If you turn off your water heater, your interior temperature will drop, leaving the water in your pipes susceptible to freezing.
Your pipes will eventually begin to thaw on their own once the temperatures rise above freezing.
DURING freezing weather:
Open cupboard doors under sinks, especially where plumbing is in an outside wall, to allow interior heat to warm the pipes. If you plan to be away from home for several days, shutting off the water can reduce the chances of broken pipes.
While frozen pipes often burst because the water inside expands as it freezes, they don't always burst. However, the risk of bursting remains when pipes freeze.
Likely places for frozen pipes include against exterior walls or where your water service enters your home through the foundation.
There are several methods you can try, including a hair dryer, heat tape, or a space heater. You can also attempt to thaw out the pipe by simply turning up the heat in the home, but this will take much longer than one of the previously mentioned methods.
Turn the Heat Upin the Property: You can attempt to thaw the frozen pipe by increasing the temperature in the property. Turning the thermostat up may be all that is needed to allow the ice blockage to melt.