Water main valve at a private well pump water tank (C) Daniel FriedmanHow to Turn Water Back on in a Winterized or Shut Down Building

  • WATER SUPPLY TURN-ON - CONTENTS: A step by step guide to staged water turn on procedure in a building to detect leaks and prevent water damaged from leaky supply or drain piping. How to restore water supply to a winterized or shut-down building. How to de-winterize a building and restore the plumbing & heating systems to service
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    Turn on building water supply:

    De-Winterizing Guide. This article explains how to turn the water back on in a building that has been previously winterized or shut down. We include warnings about possible surprise leaks and what to do about them to prevent building damage.

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    The articles at this website will answer most questions about freeze protection for piping and other building plumbing and heating system components: how to winterize a building to avoid frozen pipes, and how to thaw frozen water supply & drain piping, wells, & water tanks.

    Staged Steps in Turning on Water Supply System to Minimize Water Leak Damage in buildings

    This article describes a staged step by step approach to turning on water in a building where the water supply has been shut down over a winter or during a period of absence. The staged approach lets us check each building area and fixture one by one, minimizing the chances of extensive water damage even if a leak has occurred while the building was unattended.

    Even for buildings located in areas not subject to freezing and burst pipes, a staged water turn-on approach is useful. A pipe may have been damaged or cut by building activities, a trap may have corroded through, or other plumbing damage may be present even if no freezing conditions occurred..

    Step 1: Repair any supply piping or drain leaks found by visual inspection

    Heating baseboard freeze damage leak (C) Daniel Friedman Frozen burst water supply pipe (C) Daniel Friedman

    The photos above show two visually obvious water supply pipe leaks that need to be repaired before hot water heating (above left) or water supply (above right) can be turned on in this building.

    Don't turn on the water supply before any known cut or broken pipes have been repaired. Well this is not exactly true. You may think that all cut or broken pipes have been repaired and then try turning on the building water supply.

    Step 2: Repair any drain piping leaks found by visual inspection. Replace any open or damaged plumbing traps

    Plumbing trap made from car radiator hose (C) Daniel Friedman

    Don't turn on the water supply before you have also restored the drain piping system including all fixture traps.

    As you are checking and replacing plumbing traps at sinks and at showers or tubs where the traps were removed for winterizing, check for and replace any traps that are corroded or in poor condition.

    Making this repair now will head off troublesome drain leaks later.

    If you find faux-plumbing traps such as the one in our photo (left) made from a car radiator hose, install a proper P-trap and plumbing fittings instead.

    The drain piping shown is unsafe because it lacks a water trap to prevent sewer gases from backing up into the building; stains on the floor of the sink vanity show us that we have had a history of leaks at this drain as well.

    Step 3: CLOSE all faucets indoors and outside. Turn OFF hot water. Turn OFF other water supply shutoff valves

    Closing every faucet makes sure that you can open and check each fixture individually without being flooded by leaks in one area of a building while you're checking somewhere else. Don't forget to close outside hose faucets as well as all indoor faucets.

    If the building was winterized and pipes drained, chances are that all faucets and valves were left "open".

    Water heater shutoff valve (C) Daniel Friedman

    Don't turn on the water supply before closing all supply piping drains that were left open.

    Check & close the water inlet valve at your water heater and turn off the inlet valve on the cold side - which should be the only valve at the heater (valves on both inlet and outlet pipes are unsafe and risk a heater explosion).

    This is a convenient spot to turn off all hot water supply in the building - a step that lets us first test the cold water supply piping for leaks before moving on to checking hot water supply piping.

    Our photo (left) shows that the yellow water heater shutoff valve is in the "open" position and needs to be closed for the procedure we are discussing.

    Water heater relief valve ok (C) Daniel Friedman

    Check the water heater pressure/temperature safety valve:

    If the water heater has a manual lever that opens the water heater pressure/temperature relief valve, make sure that safety device has also been closed to its normal position before turning on building water.

    Our photo (left) shows a pressure/temperature relief valve on a gas-fired water heater that is in its normal, "closed" position.

    The relief valve is sometimes left "open" with the metal lever pointed "out" or in the horizontal position to hold the valve in the open position when a water heater tank is being drained. That step lets air into the tank so that water can run out of the tank. If the heater valve is not returned to the closed position water will simply run out of it when the tank is re-filled.

    Unless you're a plumber and have a spare relief valve on hand it's best to leave this valve alone.

    Close building plumbing supply pipe area shutoff valves: First, if the building has additional water supply control valves that shut off water to various building areas, let's close each of them so that we can later open them one by one. If the building was winterized in a freezing climate it is likely that all of these valves were left open to drain piping earlier.

    If you cannot close an old corroded water shutoff valve, don't force it as you may break it and cause a worse problem. Just add this valve to your list of necessary plumbing repairs.

    Step 4: Turn ON the building water supply at the main valve

    Schematic of a main water shutoff system (C) Carson Dunlop Associates

    Municipal or community water supply: if your water is supplied by a municipal water main, turn on water at the main water shutoff valve.

    Look for leaks at the water shutoff valve itself, then look and listen for other leaks as we describe in more detail below.

    Stop, look, and listen for leaks at the water main valve or water pump and water tank. Also look and listen for leaks in the supply piping nearby.

    Main water shutoff system (C) Daniel Friedman

    Private well and water tank systems: if your water is supplied by a private well take these additional steps:

    Turn off the water shutoff valve at the water tank. This is the valve that lets water out of the water tank to supply the building piping. Most water pressure tanks will have only a tank outlet valve between the tank and the building water supply piping.

    In our photo the water valve at the bottom of this pressure tank is in the "open" position - the the handle is parallel to the pipe.

    For the procedure we are starting here, this valve should have been left in the up or closed position.

    Make sure any valve between water pump and water pressure tank inlet is in the open position: But some systems include an additional shutoff between the water pump and the inlet to the water tank.

    If this valve is shut and the pump turns on, depending on just where the pump pressure control switch is installed, the pump may short cycle on and off rapidly or it could even be damaged or burst a part or pipe - a dangerous condition. Make sure that any valves between the water pump itself and the water tank inlet from the water pump or well are in the open position.

    Jet pump will need to be primed (C) Daniel Friedman

    Do we need to prime the water pump? If the water pump is above-ground in the building or in a well pit, the pump may be dry and it may need to be primed through a priming inlet port on the pump itself.

    Our photo (left) shows a two-line jet pump that will need priming through its top plug if it was drained and left dry during building shut-down or winterizing.

    If building water is supplied by a private pump and well system, you may need to bring along water to re-prime the well pump.

    Don't let a well pump run "dry" for more than 30 seconds or there is risk that you will damage the water pump's impeller, bearings, or other internal parts.

    If the water pump is a submersible unit, it is located in the well pipe and under-water - it does not need to be primed.

    Water pump electrical switch (C) Daniel Friedman

    Turn on the water pump. The pump should turn on, pressurize the water tank, and turn off.

    If the pump turns on but does not turn off check that the shutoff valve supplying water to the building is indeed closed - otherwise your system may be pumping water out of an open faucet or a leaky burst water pipe.

    If you are having other problems with the well pump not turning on, not turning off, or not reaching a normal water pressure, see the diagnostic articles


    Stop, look, and listen for leaks at the water main valve or water pump and water tank. Also look and listen for leaks in the supply piping nearby. If there were no other shutoff valves to individual areas of the building, look and listen for leaks in supply piping throughout the building before continuing to check individual plumbing fixtures (Step 6-below).

    Of course if you detect a leak in the water supply equipment, tanks, or piping system turn the water supply off immediately and remove any spills before starting the leak repair.

    Step 5: Open water shutoff valves that supply water to each individual building area, one by one

    Dripping water faucet (C) Daniel Friedman

    If multiple water valves were turned off during building shut-down, open them one at at time, checking for leaks in each individual individual building area before continuing.

    If your building is simple, with just a few areas where plumbing pipes and fixtures are present you can omit some of the detailed steps we describe here, look for leaks, and proceed to Step 6.

    Stop, look, and listen for leaks at the water supply piping and fixtures in each individual building area supplied by the water valve you have opened.

    If the individual plumbing fixtures such as toilets and sinks have individual hot and cold water shutoff valves, those are usually left in an "open" position unless someone already knew that the fixture was leaky.

    Our photo (left) shows a dripping faucet. This will be a lower priority leak repair than a leak in a supply pipe because the drip sends water into the building drains, not into the building walls, ceilings, or floors - provided that the drain pipes are also not leaking.

    Step 6: Turn on and test individual plumbing fixtures - brief test

    Toilet water supply valve (C) Daniel Friedman

    Once you are confident that there are no obvious leaks in any of the building supply piping, test each individual plumbing fixture for operation by opening its faucet, first cold, then hot water; look for functional supply and drainage, but run just a quart or so of water first, checking that the fixture trap is not leaking.

    Our photo (left) shows a toilet supply valve being turned back on to test that fixture.

    Stop, look, and listen for leaks.Do not leave after turning water on at a previously winterized or shut-down building before you have spent some time looking and listening for leaks, including the hiss, spurt, or just drip of a water supply pipe that may have burst hidden in a wall or ceiling cavity.

    Step 7: Drain leak test: full water test at each plumbing fixture

    Once we have seen that the sink and tub traps are not leaking, go ahead and use the plumbing fixtures normally. When several gallons or more of water have been run into a fixture drain, check for visible leaks or sounds of dripping from the building drain piping.

    Some slow leaks in supply piping or drain piping are harder to detect - we describe these at Water Supply/Drain Pipe Leak Types.

    Stop, look, and listen for leaks.Do not leave after turning water on at a previously winterized or shut-down building before you have spent some time looking and listening for leaks, including the hiss, spurt, or just drip of a water supply pipe that may have burst hidden in a wall or ceiling cavity.


    Building Freeze Protection Articles


    Continue reading at WATER SUPPLY / DRAIN PIPE LEAK TYPES or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

    Or see DRAINS & TRAPS RESTORATION to continue building de-winterizing procedures.


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