If you are replacing that outdated toilet with a new water efficient model, you may be tempted to tackle the job yourself. Replacing a toilet seems like a job that should be within the ability of most homeowners with basic mechanical skills and in theory it is.
However, there are several problems that can arise when replacing a toilet so if you are not completely comfortable with your ability to meet these challenges, it is well worth the expense of hiring a professional plumber to install the new toilet.
One thing to consider is how long the existing toilet has been in place. The older the toilet is, the more likely you are to encounter problems with the replacement. Fittings are more likely to be corroded in place or damaged during removal on an older toilet.
One of the first things that can go wrong is the water shutoff valve. If this valve has not been operated in years, it can be stuck open and be damaged when you try to close it. The valve can start leaking or worse, the force required to close it can cause it to break or to damage the water supply line.
Another common problem is corroded closet bolts. These are the bolts that hold the toilet to the floor. If these bolts are rusty the nuts can be difficult to remove and many times the effort to remove them will crack or damage the flange under the toilet.
Over tightening the closet bolts during reinstallation can crack the base of the toilet. The same thing can happen with the bolts that hold the tank and base together.
The new toilet can leak at the wax ring if it is not properly installed. You may not notice this leak which can damage the floor under the toilet. Other places with leak potential include the water supply line, the base of the fill valve, and between the tank and the base.
