How to Replace a Water Heater

There are countless good reasons to replace a water heater. If your family has grown or you have purchased a new dishwasher, your hot water needs may exceed those of just a few years ago. Alternately you may have read about different designs that are better for the environment, including sleek energy-efficient models and gas-powered versions. Simply put, if the old heat no longer meets your standards, it is time for a change.

The first thing you need to do is select a replacement that will save you money, power and water for years to come. Most home models come in 40 or 50 gallon versions at various recovery rates, though you can also find greater speed and capacity as you move into so-called industrial sizes. The good news is that water heaters are essentially self-contained machines, meaning you only need to connect a few feeds to get everything up and running. If you can manage the weight without injury and perform some basic home plumbing, this project can be completed in a matter of hours.

The most important step is to shut off any lines that could pose a hazard – water, gas and electricity. If you are replacing one electric heater with another, you will also need to check local building codes to ensure the different size and capacity are properly placed in your basement. Issues such as weight and height can play a part in earthquake zones, for instance, and safety statutes often require a significant buffer between the heater and common living spaces.

Once everything is shut off, you will need to sever the feeds that served the old heater. Generally these can be unscrewed without much trouble. The most common unions are made of threaded metal that can be discarded once removed. Newer unions can then be matched to your replacement heater’s needs and common types include copper and thermoplastic piping. If necessary, attach flex connectors to make everything reach the new heater, being careful to install a cold water gate valve so the lines run smoothly.

If you are fusing pipes together, special care must be taken with solvent welding or sweat soldering. Simple procedures like these can be dangerous if the area isn’t adequately ventilated. It is especially important to attach everything in the right order – pipes, fittings and unions will only fit together if each part has been allowed to cool. For sweat soldering, that means using sandpaper first to “tin” the surface and remove any oxidation, then being sure to use plenty of soldering copper for a uniform fit. Pressure and patience finishes the job, following which any flex connectors can be firmly attached.

As you fill up the new water heater, you will want to turn on hot water faucets throughout your home to let any air that may be trapped in the system. Depending on the amount of time and capacity required, your new heater should be ready to operate within a few hours. Make sure that everything is firmly fitted and connected before you turn the power back on, however the temperature and pressure relief valve must be in place so your heater safely lets excess energy into the relief line.

If you are replacing a gas water heater, a few additional steps will require your attention. First and foremost, it is essential that you let a professional come and install a gas line if there isn’t one already present. Assuming you already have access to natural gas in this part of the house, you will need to install a new draft hood (and remove the old one) before you operate the heater at all. Attach new vent pipes, erring on the side of more vertical rises and steep horizontal slopes to ensure unwanted exhaust always rises out of the space.

Once the new heater is installed, it should require little in the way of maintenance. Occasional draining is recommended to clean the walls, and you want to check the pressure valve every month or so to avoid a dangerous situation. For gas heaters, be sure and contact a professional if you smell a leak. With these simple preventive measures, you should rightly expect that heater to work flawlessly for years to come.

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