Introduction

Fitting a new wc suite can be quite straightforward if you are replacing like-for-like, however it can get quite complicated if you are fitting a completely different style of pan and cistern.

Regardless though, the cistern feed and overflow can be re-routed if necessary, the golden rule though is to make sure you do not damage the soil pipe as this can make fitting the new pan a real pain.

If you are moving the WC, or installing a second one in a different part of your home, it will need to be connected to the main soil pipe. Ideally the new WC will be located close to, or directly over, the existing soil pipe, if this is not practical then you can use a macerator and small bore piping to achieve the same end. This isn't an ideal option though.

• Guide to macerators

Removing the old wc cistern

Before commencing work dismantling the pipework to the cistern, turn off the cold water supply and then drain the cistern. Use the following link for a step-by-step guide to draining a wc cistern:

• Draining & isolating the plumbing system

Once the cistern is empty of water it can be removed from the wall. Traditional high-level cisterns are usually mounted onto ornate wall brackets, whereas more modern low-level cisterns are usually bolted to the wall.

• Due to it's location, it's worthwhile enlisting a spare pair of hands to lift a high-level cistern from its brackets to avoid unecessary accidents.

• Using a plumbers wrench, loosen the large nuts connecting the flush pipe to the base of the cistern and the back of the pan. If they are corroded and will not loosen, then cut the flush pipe with a hack saw as near as possible to both connectors.
• Remove the fixing screws connecting the back of the cistern to the wall, or lift the cylinder off its support brackets.
• If replacing a high-level cistern with a low-level one, then remove the brackets from the wall. They may need to be levered with a crow-bar if necessary.
• Place the old cistern to one side. If you're planning on using it with the new pan then now is a good opportunity to give it a good clean.
• If you are replacing the cistern, you may want to re-use the float valve and flush mechanism in the new cistern. If so remove them now using a wrench.

Removing the old wc pan

To remove the pan, you will first have to empty it of water. This is best achieved with a bucket and an old mug, using the mug to bail water into the bucket.

• If the pan is screwed to a wooden floor, remove the screws and loosen the pan from the floor, using a chisel if necessary.
• If the pan is attached to a concrete floor, drive a chisel under it all round to free it from the floor.
• If the pan has a p-type trap then the outlet pipe will pass through the wall. Scrape the putty from around the joint between the trap and the soil pipe.
• Attempt to free the pan by pulling it outwards and rocking it at the same time.
• If the pan will not come free then using a club hammer, smash the outlet (trap) from the pan. Be careful not to damage the soil pipe. Remove the pan and then carefully chisel away the remains of the pan outlet from the soil pipe.
• If the pan has a s-type trap then the outlet from the pan will pass straight into the floor. Smash the trap using a club hammer and remove the pan. Chisel away the broken fragements from the soil pipe, be careful not to damage the soil pipe in doing so.
• Clean the floor of any putty or sealent using the chisel.

• Stuff rags into the soil pipe when working on it with a chisel, to prevent debris falling into the drains.

Pan to pipe connectors

Place the new pan in position and check it's alignment to the soil pipe. This will give you a good idea of which pan-to-soil-pipe connector you will need.

There are a variety of connectors to account for most situations, when choosing the right one note the following dimensions:

• The external diameter of the pan outlet pipe
• The internal diameter of the soil pipe
• The distance between the outlet and the pipe when the pan is in position

• Make sure you check the connection between the soil pipe and the pan before permanently fixing the pan to the floor.

• Find a Tool Hire Centre near you

Installing the new pan and cistern

Once you are happy with the siting of the new pan, and the connection with the soil pipe, then:

• Push the plastic connector onto the pan outlet.
• Check for obstructions inside the opening to the soil pipe.
• Slide the pan into place whilst simultaneously pushing the connector firmly into the soil pipe.

With the soil pipe connected to the pan, you can now firmly fix the pan to the floor:

• First pre-drill the floor through the screw holes in the base of the pan. In a concrete floor drill and plug the holes.
• Connect the flush pipe to the pan, using the appropriate connector.
• With assistance, hold the cistern in place, lining the flush pipe up with the base of the cistern and making sure everything will connect easily.
• Sit the pan on a bed of silicone sealant, then push the screw sleeves provided into the screw holes. Give each screw a 360° rotation in turn to slowly fix the pan in place, this helps prevent cracking the pan.
• If it is not possible to fix the pan to the floor with screws then you must rely solely on sealant to hold it in place. In this case leave it 24 hours before fixing the cistern to ensure pan has bonded securely.

• Do not fix a pan to a concrete floor using cement or a strong adhesive, as this will likely damage the pan and invalidate its warranty. Silicone sealant is more than adequate in most cases.

With the pan in place, the cistern can be attached to the wall:

• Pre-drill the wall for the cistern retaining screws, in the holes marked earlier (see above).
• Hold the cistern against the wall and check that the lid fits snugly. If needed use tap washers against the wall to allow the cistern to protrude from the wall, allowing the lid to fit correctly.
• Use galvanised screws to ensure they will not rust, and fix the cistern to the wall. Remember to use washers inside the cistern to prevent water leaking through to the wall behind the cistern.
• Connect the flush pipe to the base of the cistern using the appropriate connector.

All that remains now is to install the float valve, and the flush mechanism inside the cistern. Use the following link for a guide to repairing and replacing float valves:

• Repairing valves within a cistern or water tank

Unless you are swapping and old cistern for another, you should not need to install an overflow pipe as modern cisterns are designed to overflow into the pan. If you do need an overflow then reconnect the existing pipework to the overflow exit on the side of the cistern.

Ammendments to guide for different types of wc suite

Concealed cistern are hid behind a partition, which is often either plaster board and wooden batterns (which are tiled) or pre-finished wooden (or wood-look) boards. To fit the wc suite, the order of installation needs to be reversed...

• Mark the location of the toilet pan and cistern, by holding them in place, along with the flush and soil pipes.
• Draw a dotted line across the floor to mark the location of the partition. The placing of the partition should be such that the flush and soil pipes protrude the exact amount that they fit into the pan. Also ensure that the partition line is perpendicular to the side walls, and parallel to the back wall.
• Assemble the the soil pipe connector, ensuring it protrudes beyond the partition line, and lock firmly in place.
• Install the cistern in the same way as for a regular low level cistern, and fix the flush pipe in place.
• Assemble the panelling, ensuring to cut a hole in-line with the flush pipe.
• Slide the pan in place against the partition, and connect the flush and soil pipes. Seal the pan to the floor.
• Finally top the partition off with the top panel to hide the cistern. Remember that the top panel which sits above the cistern should be removable should you need to gain access to the cistern.

Wall-hung pans are most often fitted to a partition hiding a concealed cistern. This means that to fit them is the same process as described above for a regular concealed cistern, with the exception that the pan is fitted to the wall not the floor. There are two options when fitting the pan to the wall:

• Construct a 'mini wall' using 3 or 4 'breeze' blocks (or cinder blocks), behind the partition and under the cistern. Drill through the partition into the block wall, plug and screw the pan in place.
• A purpose built bracket. This effectively gives the pan feet. Requires fitting before partition wall as it sits behind wall and protrudes out into bathroom. The base part sits under the bathroom flooring.

Further information and useful links

• Find a Bathroom Fixtures & Fittings supplier near you
• Find a Plumbing Merchants near you
• Find a Plumber near you