Shutting Down The Plumbing System

At one time or another, you may need to put all of the fixtures, appliances, faucets and pipes in your plumbing system out of operation.

When you do major repairs or installations that call for cutting into the main pipes, or when you need to clear and recharge waterlogged air chambers, you must both shut off the incoming water and drain out the existing supply before you can start work. When you leave a house empty and unheated for the winter, you must also weatherproof the system to protect it from bursting in freezing temperatures. Whatever the occasion, be sure to reserve a few gallons of water for drinking or cooking before you shut off the supply.

If you are about to winterize a summer home, draw enough extra water to prepare an antifreeze mix that you will need to protect the traps. In order to drain your system efficiently follow this check list:

• Cut off the house water supply by closing the main shutoff valve.
• Turn off the gas or electricity to the boiler and the water heater.
• Siphon the water out of the tub of the clothes washer.
• If you have hot-water heat, open the drain faucet on the boiler and let the water flow into the floor drain. Next, open all of the radiator valves. Then remove an air vent from a radiator on the top floor so that air will replace the water as it drains into the boiler. 
• Working floor by floor, starting at the top, open all hot and cold water faucets —including all tubs, showers and outdoor faucets—and flush all toilets.
• Open the drain faucets on the water heater and the water treatment equipment, if you have any. 
• Finally, open the drain faucet on the main supply line to release any water that may remain in the pipes.

At this stage, your plumbing system will be adequately drained for repair or remodeling work. If you are closing the house for the winter, take additional precautions. Walk through the house to make sure every place where water can collect is drained.

For cold weather protection, the water still remaining in fixture and toilet traps as well as the main house trap, if you have one, must be replaced with an antifreeze solution to keep the traps from bursting while still functioning as a barrier against sewer gases. Get the nontoxic propylene glycol antifreeze sold for recreational vehicles; the ethylene glycol antifreeze used in automobiles is toxic (the manufacturer recommends that it not be brought into the house) and alcohol-based products evaporate too fast.

Mix the antifreeze with water, as directed on the label, in the same proportions you would use to protect a vehicle in your climate. (If you do not want to mix it, pour it straight from the can into the trap.) How much antifreeze you need will



depend on the proportions that are recommended and the number of traps to be winterized.

Prepare the lavatory, sink and tub traps first. Remove all the accessible cleanout plugs, drain the water from each trap into a pail or bucket and discard it; replace the plug. Pour at least a quart of the antifreeze solution into each trap. With traps you were unable to empty, pour the solution in very slowly so that it will push the existing water ahead of it into the drainpipes.

Next, wipe up any water remaining in the bottom of toilet bowls with rags or newspapers. Pour at least a gallon of the antifreeze mixture into each toilet tank, then flush the tank to dislodge water from flushing channels of the toilet bowl. The antifreeze will collect in the toilet trap.

To complete the winterizing, remove either the inlet or outlet plug of the main house trap, if you have one, and siphon out the water in the trap. Pour about a quart of antifreeze into the trap and replace the plug. If you have your own well system, drain the water tank and dry off all parts of your pump—unless it is a submerged one, which requires no special precautions.

Come spring, or after the repair is completed, you will have to refill your system. First, close the drain faucet on the main water supply line. Close all the faucets throughout the house including those on the boiler, hot-water heater and water treatment equipment. If you have hot-water heat, replace the air vent on the radiator from which it was removed. Then open the main valve slowly to bring fresh water into the system.

Finally, turn on the gas or electricity supply to the boiler and hot-water heater and light the pilots on gas-fired equipment. Faucets will sputter when you first use them because of air trapped in the pipes, but this condition will correct itself quickly. The antifreeze mixture in the traps and toilets will flush away naturally as the fixtures are used.

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