Simple Guide on how to replace toilet tanks


Having to fix toilet tanks may seem like something that requires plumbing expertise of the highest level; well, I beg to differ, it’s absolutely easy to achieve and doesn’t require too much knowledge, just the common instinct of knowing how to use your hands. The intention of wanting to replace your tank might come from a place of wanting to change an old design to a new one, or due to un-repairable damage; maybe breaks or cracks.

The basic intention however, is wanting to have a new one to keep the gent looking fresh, clean, having it safe and keeping your appliances/ toilet running efficiently because it’s quite annoying seeing faults from appliances you spent money on fixing. We can relate.

The process of tank replacement and installation will be discussed in this article; with easy to follow steps, simple tips on what to do to prevent future issues and a video to help you understand better. Follow us through as we guide you. Let’s get into it


STEP 1; Attaining all needed material and tool;

Yeah Yeah, the intention of you reading this is to install a new tank, we know; but have you gotten the new tank you wish to install?. It’s a silly question but still it’s quite vital. All needed materials and tool have to be on ground and available at an easy reach. Looking for tools to use while the operation has started is poor practice which is also very unsafe.

Alongside the tank, a small list of materials and tools would be needed to start and finish the process smoothly. Some of them may come with the toilet tank when you purchase and some, you might need to buy separately. Here’s the list regardless;

Materials Tools
Water tank Adjustable wrench
Flush valve gasket Hacksaw blade (optional)
Plumber’s putty Large sponge
Teflon tape Plumb level
Additional nuts and washers (optional) Human or an assistant (optional)


 STEP 2; Cutting off supplies;

With all materials and tools ready and available, cutting off the water supply to tank is the next thing to do. Ideally there should be a valve controlling the supply to the toilet alone. If so, it’s best to have that valve used because turning off another valve at other locations will stop the circulation of water to other appliances.

However, if a control valve does not exist within your toilet areas, its best advised to trace the general control valve for the gent. It should about 2 meters above the ground close by inside the ceiling. When gotten, have valve closed and ensure water flow has stopped within supply pipe.

STEP 3; Setting asides tools and materials;

Now it’s understood that this may seem unnecessary, but for proper safety practices, it is. Follow this few sub-steps

  • The first thing you want to do is to set the lid of the toilet tank down gently, it’s a fragile material, breaking or cuts from it could cause serious injuries
  • Offload any tool and material you have on you and place them on the floor close to the toilet, but on the side of the room to prevent obstruction or impact by them. These should be tools or materials you need for the job. Any other should be placed away from work area, safely.
  • The newly purchased tank should be placed gently on the floor or on a flat surface strong enough to accommodate its weight; but away from the material and tools. This registers a clear picture in your mind on where tank, materials and tools are placed and provides a clear work area with enough space to maneuver during operation.

STEP 4; Draining contained water;

Alright, it’s an ideal scenario. The equipments and materials have been set aside, the supply to the tank has also been stopped but there might still be existing water within. Flushing the toilet is the best way to get rid of the contained water. So the flush mechanism is activated by pressing, ensure that during the flush, the handle or button is held down for about 10 to 15 seconds to allow for all possible discharge.

After its seems like no more water can be discharged, a small amount might remain within, the use of the sponge then comes to play; the sponge will be used to gradually dry out the insides of the tank until it looks absolutely certain that when tank is removed, water will not come out from.

NOTE; Having water on floor during operation can be hazardous and might cause accidental scenarios leading to injury.

STEP 5; Loosing connections of tank;

The adjustable wrench which is an open end wrench with a movable jaw is a versatile instrument used in plumbing; it can be adjusted to any required diameter of bolt and can loosen them efficiently.

The nut under the toilet tank used to attach the tank to the bowl can be loosened with the use of this wrench or if not too rusted, it can be loosed from the inside of the tank with the use of a large screwdriver but this option sometimes doesn’t work.

The removal of flexible cord used for supply is another feat. The short cord that supplies water from supply line to the tank can be loosened but turning the nut anti-clockwise with bare hands or with the use of the wrench. The bolts, nuts and washers removed are vital and should be kept safe amongst the materials set aside.

NOTE; The flexible cord should be left bare and should not be loosened from the wall

STEP 6; Displacement of tank;

After loosing all connections, tank should be properly removed and displaced. It requires little to no technicality as it just involves lifting and dropping; the tanks can be surprisingly heavy and slippery, therefore care must be taken.

Tank however should be placed not too far away from the work area and on a surface that is flat preferably where the new toilet tank was placed a short while ago

STEP 7; Installation of new toilet tank;

The installation of the tank is the main deal; any minor or major mistake could lead to damage of tank, slight injuries or in rare cases, major injuries; so extra care should be taken at this stage. Steps on how to install tank will be broken down critically into the sub-steps below to help you understand;

  • Examine the new tank; this could’ve been done during your time of purchase, we get it, but it’s advisable you do so again to make you understand how to place the toilet tank on the bowl and in what position it should be placed. Sometimes having precautionary steps deflect hazards you had no idea were coming your way. The presence of a flush valve gasket underneath the center of tank should be checked, if it is not present, you can easily fit one on by just wearing it on the nut-like object under the tank (at the center).
  • Mount the toilet tank rightly above the bowl; make sure holes for bolts and flush gasket are in line, with the gasket entering its hole partially firmly. Plumber’s putty should be applied on gasket to prevent leakages from tank in the future.
  • Fix bolts within holes; this is a part where most people tend to make slight mistakes. What mistake is that, you may ask?; the mistake of tightening the bare bolts without the use of the plumber’s putty or the Teflon tape. Before having bolts placed in the holes, apply a bit of plumbers putty around the top threaded area and insert the first washer, the bolt should then be fixed from inside the tank; the use of the second washer should be applied at the external part of the tank on the other side of the bolt, then a backup washer should be fixed before inserting the nut. Same process should be applied for other nuts to be fixed.

NOTE; The use of a Teflon tape can also be utilized, the Teflon tape can also be wrapped around the top threaded part of the  bolt to allow for easy screwing in of nut and easily removal in the future.

  • The use of plumb level will be required before tightening the bolts to ensure tank is on a perfect horizontal line. The plumb should be long enough to cover the width of the tank and should be used without the tank lid on top.
  • Gently pressing the sides of tank when screwing each bolt can be done to allow for firm grip by bolts; having the plumb level while tightening bolts is best to ensure your final procedure of tank installation is perfectly done and tank is horizontally in the right line; care should be taken when screwing bolts with adjustable wrench, too much applied force from wrench may crack the toilet tank, damaging it and causing extra expense of probably buying a new one which I’m sure you won’t want to do.

STEP 8; Reconnection to water supply;

After installation has been achieved to this stage, the complementing step is the re-connection of water supply to the tank, when connecting the flexible hose/cord to the toilet tank, “the fill valve” which is the mechanism that takes in water and fills tank should be gently pressed down so hose can be properly tightened to it

The pressing is however not required in all cases but the use of the wrench can be employed to make sure tightening is done properly.

STEP 9; Testing of installed toilet tank;

The deed has been done, your toilet tank has been installed with reconnection to supply line but testings are required to ensure there are no leakages from any part of the tank. The testings are quite simple and require little effort. With the use of bucket or from normal supply, fill the toilet tank with water and flush, fill tank with water again and flush again, this should be done 3 to 4 times and connection points with overall tank should be checked for possible leakage

If any, either proper tightening or adding of the plumber’s putty should fix the problem.

STEP 10; Releasing of water supply and clearing of area;

If this hasn’t been done already, it’s advised that locked valve used to stop water flow should be loosened to allow the release of water.

Clearing of area should also be taken into consideration; tools and materials used should be cleared from work area alongside the cleaning of any water residue on floor. This is proper practice which will give optimum satisfaction regarding your work and ensure safety after job.




Joe Taylor

Over 2 decades of remodeling experience, Joe is an expert in home improvement. He is now the Managing Editor of PlumbJoe where he writes guides for homeowners. His hobbies include climbing, running and playing the piano.

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