The short answer on difficulty
An electric tank heater in an accessible spot is the easiest case, and a skilled homeowner can manage it with a helper. A gas tank heater is harder, because of the gas connection and the vent. A tankless conversion is the hardest, since it often needs a larger gas line, new venting, and electrical work.
The weight is part of the difficulty. A filled tank is heavy, and moving it through a garage door or down a hallway takes two people and a dolly.
Difficulty by heater type
Fuel and location set the level of difficulty.
| Heater type | Difficulty | Main risks |
|---|---|---|
| Electric tank, same size | Moderate | Wiring errors, heavy lifting |
| Gas tank, same size | Harder | Gas leaks, venting, carbon monoxide |
| Tank to different size or location | Hard | New piping, venting, and permits |
| Tank to tankless | Hardest | Gas line upsizing, new vent, electrical |
What the job involves
You drain the old tank, disconnect water, gas or power, and vent, and remove it. Then you set the new tank, connect new flexible water lines, install a relief valve with a proper discharge pipe, reconnect gas with a shutoff and a sediment trap, and reconnect the vent.
After that you fill the tank before restoring power or gas, check every connection, and light or energize the heater. Each step has a failure mode, and a gas leak or a poor vent is not something to learn on the job.
Gas and carbon monoxide safety
If you ever smell gas, which is often described as rotten eggs, leave the building right away. Call 911 and your gas utility from outside. For natural gas in this area, that utility is Southwest Gas. Do not turn lights on or off, and do not try to fix the connection.
A poorly sealed vent can send carbon monoxide into the home. Keep a battery-powered carbon monoxide alarm near sleeping areas, and have a plumber check the vent after any gas heater work.
Steps that often trip up DIY installers
Watch for these.
- Skipping the sediment trap on a gas line, or reusing an old flexible gas connector.
- Capping or plugging the relief valve discharge pipe.
- Failing to check for a closed system that needs an expansion tank.
- Wiring a 240-volt electric heater without confirming the breaker and wire size.
- Not checking the draft on the vent after the heater is running.
Sizing and choosing the new heater
A heater that is too small runs out of hot water, and one that is too large wastes energy. The right size depends on how many people live in the house and when they use hot water. Look at the first hour rating on the label, which tells you how much hot water the heater can deliver in an hour.
A plumber can size it for your household. Our page on water heater replacement explains what we check before we install.
Permits, safety, and who to ask in Sahuarita
Permit rules vary, and the Town of Sahuarita's website does not list water heater requirements on the page we reviewed. Ask the Town's building safety department, which lists 520-822-8866 on its contact page. If you live in Green Valley, ask Pima County instead.
Southwest Gas is the natural gas utility for the area. If your project changes the gas line, ask whether the utility or the Town needs to be involved. A licensed plumber handles that routine for you.
When it is worth hiring a plumber
Hire a plumber if the heater is gas, if the vent needs work, if the tank is in an attic, or if you are not sure what the old setup includes. A professional also hauls away the old heater, which is a job in itself.
If your heater is leaking right now, shut off the water and power or gas and call. Our water heater installation page explains the process, and the Green Valley page covers that area.
Disposal and cleanup
A used tank is awkward to remove. It may still hold water and sediment, and it weighs a lot. Many scrap yards take old tanks, and some haulers do it for a fee. Ask your plumber if haul-away is included.
Drain the tank to a floor drain or outside, and watch for hot water. Wait for the tank to cool or drain it carefully, since scalding water is a common injury during a swap.
Safety checklist for a replacement
Run through this before you power the new heater.
- Confirm the relief valve and its discharge pipe are installed correctly.
- Fill the tank fully before turning on power or gas.
- Test every gas joint with soapy water, looking for bubbles.
- Check that the vent draws properly and is sealed.
- Install or test a carbon monoxide alarm near sleeping areas.
The standards you are working within
Gas heaters are certified to ANSI Z21.10.1 and electric heaters are listed to UL 174. The gas connection follows NFPA 54, the National Fuel Gas Code, and the wiring follows NFPA 70, the NEC.
According to Southwest Gas safety guidance, anyone who smells gas should leave the building and call 911 and the gas utility from outside.
Water heater replacement questions in Sahuarita
Can I replace a water heater myself?
An electric tank in an easy spot is possible for a skilled DIYer. Gas and tankless are better left to a plumber.
How long does a replacement take?
A same-size swap often takes part of a day. Conversions take longer.
What do I do if I smell gas?
Leave, then call 911 and your gas utility from outside. Do not touch switches.
Do I need a permit?
Permit rules vary. Ask the Town of Sahuarita building safety department, or Pima County in Green Valley.
How do I size the new heater?
Use the first hour rating and your household's peak use. A plumber can do the math.
Do you replace heaters in Green Valley?
Yes. See the Green Valley page.