Water Heater Safety Tips for the Homeowner

How to get the most out of your water heater!

Our homes have many components – structural, electrical, HVAC, plumbing, appliances, to name a few. Generally speaking, we as homeowners follow the old adage, “If it ain’t broke, don’t fix it.”. Well, that might be fine if we’re talking about a cordless drill, but when it comes to the water heater, that could be a costly and dangerous attitude. Our water heaters need attention just as our vehicles need attention.


In this article I provide you with a general guide to water heater safety and maintenance. Maintaining your water heater is necessary for it to operate safely. Since most homes I inspected during my tenure as a home inspector had tank-type gas or electric water heaters, those will be our focus here.

I am not a code inspector and the information in this article is not intended to take the place of the owner’s manual. Please follow the instructions in your owner’s manual for your specific water heater. Most water heaters have the owner’s manual inserted in a plastic sheet protector adhered to the side of the unit. If you can’t find it, please go online and search “water heater manual”.

Electric water heater diagram

Here is a sample diagram of an electric water heater.

electric water heater diagram

Some models have two access panels but only one heating element. If you were to remove the upper panel, you would see the outside of the tank but no heating element. Why, then, do they have two access panels? I have no idea!

There are only two reasons for you to open the access panel(s):

  1. to ensure the temperature settings are at 120 degrees Fahrenheit;
  2. to inspect for leakage during your yearly inspection.

If you’re a DIYer, you will also open the access panel if you need to replace a bad heating element.

Gas water heater diagram

Here is a sample diagram of a gas water heater.

The main differences between an electric water heater and a gas water heater are:

  1. the heat source is gas, not electric;
  2. a gas unit has an exhaust system;
  3. the thermostat is on the outside of the unit.

Where is my water heater?

You’d be surprised how many people have no idea where their water heater is. Obviously if they don’t know where it is, they’re not maintaining it.

Do you know where yours is? It’s most likely in one of four places in your home:

  • the garage,
  • an interior closet,
  • the laundry room,
  • the attic.

Regardless of its location, it must be maintained. Failure to do so can be costly and deadly.

Make sure your water heater is readily accessible. This means you can get to it without having to move anything. A clear path makes it easy to get to and leaves you no excuse for not maintaining it.

Keep flammables and combustibles away

In addition to keeping a clear path to your water heater, you should also keep the area around it clear. Whether it be a raised platform in the garage, the floor of an interior closet, or the attic floor, avoid using it as a place for papers, aerosol cans, paint thinner, gas cans, or the like.

The TPR valve and discharge pipe

All tank-type water heaters have a temperature and pressure relief (TPR) valve. This valve is near the top of the water heater. On some water heaters the valve is on the top.

The TPR valve is a safety device. If the valve is not functioning properly and there is pressure build-up in the tank, the water heater can explode and “rocket” through the house and into the air. Property damage, personal injury, or death can result. Therefore, the valve must be tested according to the manufacturer’s instructions.

Before testing your TPR valve, confirm the following:

The TPR valve should:

  • have a discharge pipe properly attached to it;
  • point in a downward direction, never in an upward direction.

The TPR’s discharge pipe should:

  • be in good condition, not damaged;
  • run downhill, never uphill;
  • terminate to an approved waste receptor or to the exterior in a conspicuous place;
  • point to the ground at its termination point;
  • be between 2 and 6 inches from the ground;
  • not terminate to the crawl space;
  • not:
    • have a tee fitting in it or be connected to any other pipe;
    • have a faucet or elbow attached to its end.

If the discharge pipe terminates to the exterior, I recommend getting in the habit of visually checking the discharge pipe’s termination point for dripping or trickling water every time you pass by. Dripping or trickling water would indicate there is a problem with the TPR valve.

As a reminder, check your user manual for proper installation procedures. If something doesn’t look right to you, consult a licensed plumber.

Testing the TPR valve

Before testing (opening) the TPR valve, make sure no one is in the area. Hot water could splash out and cause personal injury.

Do not test (open) the TPR valve if the discharge pipe is not present or is not installed according to the manufacturer’s instructions.

Generally accepted plumbing practices recommend testing your TPR valve every 12 months and replacing it every three to five years. Again, follow the manufacturer’s instructions in the user manual.

To test the TPR valve, simply flip open the lever on the valve. Water should flow out freely. Allow two to three gallons to flow before closing the valve. The static water pressure to most homes is between 40 and 80 pounds per square inch (psi). At 40 psi, it doesn’t take long – probably less than a minute – for several gallons to flow out a properly-working TPR valve.

After closing the valve, watch the end of the discharge pipe. You will see residual water trickling or dripping out for a minute or so after you close the valve. If the trickling or dripping continues, it’s likely there is debris caught in the TPR valve. Strike the valve a few times with a hammer or wrench (don’t kill it!), and check again for trickling or dripping.

If water does not flow freely when the valve is open, or if water continues to trickle or drip for an extended period after the valve is closed, the valve may need to be repaired or replaced.

If you had a recent home inspection, do not assume the home inspector tested the TPR valve. Testing it during a home inspection might not be required in your area, or the inspector may have had reason not to test it.

Water temperature – prevent burns and scalds

The thermostat should be set at 120 degrees Fahrenheit. A higher setting can result in scalding or burns. Consider installing anti-scald devices in water faucets and shower heads to avoid potential burns. The following chart shows how quickly the skin can be burned. It is especially important to maintain a safe water temperature if you have in your home small children, elderly, or a person with special needs.

water temperature burn chart

To check or change the thermostat setting on your electric water heater, do the following:

  • disconnect the power supply to the water heater;
  • remove the upper and lower access panels;
  • carefully move wires out of the way;
  • lift or remove the insulation;
  • use a screwdriver to turn the dial to 120 degrees;
  • put the insulation and wires back in place;
  • secure the access panels back in place;
  • restore power to the water heater.

Here is a sample image of what you will see when you open the access panel(s).

The thermostat on a gas water heater is on the outside of the tank’s front housing. Simply turn the dial to the desired setting. Thermostats vary, so be sure to read your owner’s manual. The below image is only a sample.


Safety pan

It could be a very costly mistake to think that because a water heater is in the garage, there’s no need to have a safety pan under it. Well, I’m not a code inspector, but according to the 2018 International Residential Code for One- and Two-Family Dwellings, a safety pan is required when a water heater “…is installed in a location where water leakage from the tank will cause damage…”. This would include the garage, the attic, an interior closet and a laundry room.

I submit to you that most people have property in their garage, and their property would be damaged if the tank were to leak or break and had no safety pan under it. Also, when it comes time to sell your house, the lack of a safety pan under your water heater will become an issue.

There are additional requirements regarding the size and type of pan that is to be used. There are also requirements for the size and type of drain pipe that should be connected to the safety pan. These can be found in the owner’s manual.

If your water heater does not have a safety pan under it that drains to an approved waste receptor, you should strongly consider having one put under it. It would require draining and disconnecting the water heater, but it would be worthwhile to do so.

If your water heater is more than 10 years old, consider replacing it with a new one. That would also be a good time to install a safety pan.

The below image is from an actual inspection I conducted. Notice the safety pan’s drain pipe terminates inside the garage. I was required by law to note this as a deficiency.

improper drain termination

Flushing the water heater

Flushing your water heater will help prevent corrosion inside the tank and extend the life of your water heater.

Follow the manufacturer’s instructions on how often your should flush your water heater. Factors that will affect the frequency are the hardness of your water and the number of people living in your house.

Before flushing the unit, read and follow the procedure outlined in your owner’s manual.

You will connect a garden hose to the drain near the bottom of your water heater. The hose should be long enough to reach to the outside, far enough away so the water will run away from your house, not toward it. When you begin flushing, you will notice sediment coming out of the hose. This is normal and good. The purpose of the flushing is to remove this sediment.

The 18-inch rule

If your water heater is in your garage, it should be on a platform of some sort, 18 inches above the floor. This is to prevent flammable fumes, which stay low to the ground, from being ignited by the heat source in the water heater.

The exception to the 18-inch rule is if your water heater is Flammable Vapor Ignition Resistant (FVIR). This type of unit protects the heat source from fumes hanging around your garage floor.

Additional safety checks

Gas and electric water heaters

  • periodically inspect the exterior of the water heater for evidence of leakage;
  • periodically inspect all pipe connections for leakage or evidence of leakage.

The below image is from an actual inspection I conducted. At the time of the inspection I did not observe any water leaking or dripping from the fittings. My guess is that the corrosion eventually sealed the leak, but this does not mean it can’t start leaking again. This, too, I noted as a deficiency.

leak at water pipe connection

Electric water heater

  • Make sure the access panels are in place and properly secured to the unit.
  • Make sure the cover plate is in place and properly secured over the electrical connections, usually found on top of the unit. Notice the improper connection in the image below.

improper connection

Gas water heater

  • Check for gas leaks around the supply pipe connections using your sense of smell. If you smell gas, call a licensed plumbing contractor for correction. If you’re in doubt, call the gas company or 9-1-1 and get out of the house.
  • There should be a gas shut-off valve near the water heater. It should be easily accessible and you should be able to operate it (open and close it) with any obstructions. Correction is needed if the shut-off valve cannot be completely opened or closed.
  • Make sure the exhaust flue is properly connected in its entire length. You might need to look in the attic. An improper connection can result in dangerous gases being emitted into your home. Gases going into the attic can end up in the living area of your home.

The below image is from an actual inspection I conducted. I saw this condition at least once a month. Hazardous gases were being admitted into the attic every time this gas water heater fired up.

disconnected flue

  • Make sure the exhaust flue is not in contact or near-contact (closer than one inch) with combustible materials such as wood framing or drywall (drywall has paper on it). Be sure to check in the attic as well to make sure nothing, such as personal items, is in contact with the flue.

A quick word about tankless water heaters

Tankless water heaters seem to be coming more and more prevalent these days. They are more expensive than tank-type water heaters, but their life expectancy is greater – 25 years, perhaps.

It is my understanding that the only maintenance a homeowner should perform is opening the TPR valve once or twice a year. However, a plumber told me it is highly recommended to have yearly maintenance performed by a licensed plumber. I’m sure there are plenty of YouTube videos for the DIYer, but I think I would lean toward calling a licensed plumber.


We covered a lot of material here, but much of it was informational. Maintaining a water heater is not difficult, it just takes discipline.

By maintaining your water heater, you will reduce the risk of property damage and personal injury or death. A properly maintained water heater should last as many as 12 years. Last I checked, you can expect to pay at least $1,000 to have your water heater replaced. So proper maintenance will also save you money.

As I mentioned above, this is a general guide. I could say more but I want to keep things simple.

So, if you have a question or two, please fire away. I also appreciate comments and suggestions, and accept criticism – preferably constructive. As always, I will respond in a timely manner.

Best Regards,


4 thoughts on “Water Heater Safety Tips for the Homeowner

  1. Rick, you’re right, you have a lot of info here, but it’s very educational and informative. I didn’t know about the 18″ rule. I might be wrong, but it seems all the water heaters I’ve been around sat directly on the floor? I know the one I had in my family home for 35 years, which I sold recently, sat on the concrete floor in the basement. I suppose the 18″ rule is not enforced? Thanks for sharing.

    1. Terry,

      For clarification, the 18-inch rule only applies to water heaters in garages. Gas cans and other hazardous materials have fumes that linger close to the floor. As far as enforcement goes, if there is a water heater on the garage floor, correction (being brought up to current standards) might be required by a lender before the house can be sold.

      Thanks for taking time to comment and helping me to clarify the 18-inch rule.

      Best Regards,


  2. My Dad has a water heater just sitting on the ground in his garage. I did not know about the 18 inch rule. I will share this with him immediately. You just saved my Dad and I a lot of trouble down the road. Thank you. If the garage flooded, that would have been a disaster.

    I do have a question though. My Dad and I are not much when it comes to inspecting a house for issue. Do you have a guide or recommendation for finding a good house inspector? I want to make sure my Dad’s house is safe and sound.

    Thank you so much and I hope you make it a great day!

    1. Alex,

      First things first. I highly recommend you have your Dad make sure all gas-powered equipment and gas cans are moved far away from the water heater. Second, to prevent damage to personal belongings, put them up off the ground. If the water heater leaks or breaks, water would hopefully flow toward the overhead door on to the exterior.

      You have two options. Of course, my recommendation is the first one.
      1. Get the water heater 18 inches up off the floor. This might require having to build a structure strong enough to hold the heater and its water. It will also require having to drain the water heater, and if it hasn’t been serviced in a while, it will have sediment in the bottom, making it quite heavy because the sediment will be wet, and the sediment might prevent a complete draining of the water. One more thing. Put a safety pan under it along with a drain pipe to a suitable waste receptor or to the exterior in a conspicuous place (so you can see if water is leaking or flowing out). The safety pan should have at least two inches of clearance around the water heater, otherwise if there’s a leak the water might just flow over the top of the pan rather than out the drain pipe.

      2. Wait until the water heater needs to be replaced, at which time you can have it raised and put a safety pan under it. Again, it IS an option but I do not recommend it. Water heaters have a life expectancy of 6-12 years. Check the data plate for the manufacture date. It might be about time to replace it anyway. If you need help deciphering the data plate, send me an image and the name of the manufacturer and I can find the manufacture date for you.

      Here’s a link that will help you find a home inspector: https://www.nachi.org/certified-inspectors

      However, just because an inspector is certified through InterNACHI does not mean he or she will be good. It would be wise to find two or three from this site, then check out their Website. Remember, you get what you pay for. In my opinion, a good inspection cannot be done in 1 or 2 hours.

      I hope this helps. Thank you for taking time to share your situation and for the well wishes. It’s an encouragement to me.

      Best Regards,


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