Founder | BPI® Energy Auditor Certified Professional
There are really two main reasons you might want to turn off your hot water heater.
The first is if you have an emergency of some kind and want to shut it down to avoid damage to your home or the water heater itself.
For example, if you have a water leak or your water heater starts overheating or making knocking noises.
The second reason people ask about turning off their water heater is that they want to save money. This reason is a cause for some debate, and we’ll examine the arguments for and against it in this article.
Turning off your water heater or adding a timer can help you to save a little money on your utility bills, but the extra hassle might not be worth the marginal savings. A better option might be to add a timer to automatically turn the heater on or off at specific times during each day.
The emergency shutdown procedure for a water heater is something that we hope we’ll never have to use, but it’s important to know what to do should the need arise.
In the rest of this article, we’ll cover what to do to shut down the heater in an emergency before diving into the ins and outs of the debate on whether turning your heater off saves you money in the long run.
So, read on to learn more about these topics.
Have you ever considered installing a heat pump hot water heater? They are more efficient than other forms of hot water heating and could be a good choice if you’re looking to save money. Why not read our article on the subject here?
Water Heater Emergency Shut Off
Let’s deal with the emergency first.
The last thing you want to be doing is searching for your water heater’s user manual and working out how to turn it off in the middle of an emergency.
For this reason, I would recommend taking the time to familiarize yourself with the emergency shutdown procedure for your water heater so that you know what to do in advance and don’t waste precious time figuring things out as water leaks out of the system causing damage to your home.
There are a few circumstances under which an emergency shutdown could be required. For example, in the case of a leak or if your water heater starts making unusual and alarming noises such as knocking or banging.
When this happens, it makes good sense to turn off the heater to avoid it causing severe damage to your home or the heating unit itself.
There are four steps to shutting off a water heater, which must be carried out in the following order.
- Turn off the power source. For a gas water heater, turn off the valve on the side of the unit by turning it to the “off” position. In the case of an electric water heater, turn off the power supply at the circuit breaker.
- Turn off the water supply. There should be a valve on the inlet water pipe that supplies cold water to the heater. The valve must be closed to prevent more water from entering the heater. If you don’t have a valve on the inlet to your water heater, you’ll need to go to your home’s main water valve and shut the water off from there.
- Relieve the water pressure. Relieve the pressure in the system by turning on the hot water faucets in the house and, if your heater has one, open the pressure relief valve.
- Drain the water heater (if the leak hasn’t stopped). The water heater should have a drain valve on the side of it near the base. Attach a garden hose to the valve and lead the end to a suitable drain before opening the valve to slowly drain all the water from the heater.
The next thing to do having shut off the heater is to call a plumber out to fix the issue.
Following the above steps will help minimize or prevent damage to your home or the unit while you wait for the plumber to arrive.
Does Turning Off a Boiler Save Money?
The question of whether turning off a water heater saves money is hotly debated, and there is a lot of misinformation out there.
Fortunately, we’re here to help you get to the truth.
Turning a conventional storage tank water heater off apart from when you need hot water can save you a little money. However, modern water heaters are very efficient, so the savings are very low and might not be worth the extra hassle of remembering to turn the heater on and off.
Most households don’t need water 24 hours a day, 7 days a week, so turning off your water heater when you don’t need hot water might seem sensible.
If you have a demand heating system, which only heats the water you use as you use it, your heater is already off for most of the time anyway.
This can be a much more efficient way to heat your hot water than a conventional storage tank water heater because you eliminate the standby losses.
However, even with a storage water heater, turning the unit off until you need hot water might not achieve the savings you might be hoping for.
Modern water heaters are pretty efficient and only run between one and three hours each day, so they are, in effect, already “off” for much of the time anyway.
It’s not unusual to have a modern system with a well insulated storage tank that only calls for heat once every 24 hours if the household members don’t use much hot water.
If such a household were to keep the heater turned off until just before they needed hot water, there would be no energy saving because the heater was off anyway.
One enterprising individual has published a little study that he carried out to put some numbers on the difference in cost between only turning on his heater when needed and keeping it on all the time.
He ran the experiment during the summer and went to great lengths to ensure the pattern of hot water use across the two months remained the same.
He ensured the same number of baths were run during both months and kept the heating off for the whole period (he ran the experiment during the summer, so that’s not quite as heroic as it first sounds).
The difference in cost between the two months turned out to be about $2.00 per month. It was £1.67, to be precise, as he is based in the UK, so your mileage may vary, but it does show that the cost difference is somewhat marginal.
How Do You Hook up a Heater Timer?
So, if you’d like to fit a timer to your water heater, how do you go about it?
It’s a relatively straightforward process that most DIYers could probably handle.
The job entails securing the box that houses the timer to the wall and then taking the electrical line that currently connects directly to your heater, disconnecting it from the terminal on the heater, and connecting it to the timer instead.
You then connect the timer to the terminal on the water heater with a new length of wire.
Remember to turn off the electricity at the breaker box before you start work to avoid getting electrocuted.
Some of the wiring work can be a bit fiddly, but the documentation that comes with the timer is usually very comprehensive.
The video below explains the process very clearly in a step-by-step guide.
Once you’ve hooked everything up, you can turn the electricity supply back on and set the timer to switch your heater on and off at appropriate times to help you save a bit of money.
If you are on time-variable pricing, which means that the price you pay for electricity varies throughout the day, it will make sense to set your water heater to heat your storage tank during cheaper off-peak hours and turn it off during the more expensive peak hours.
Summary
You should familiarize yourself with the procedure for shutting off your water heater so that you know what to do in an emergency.
Generally, you can find instructions on the sticker and the user manual for your particular system.
If you need to turn off your water heater in an emergency, remember to turn off the gas or electricity supply before turning off the water supply.
If a leak is the cause of the emergency, you can drain the tank to prevent water damage to your home.
Turning off your water heater to save money will give you only small savings, and you will need to remember to turn the system on and off at the correct times to ensure you have hot water when needed.
This is a bit of a hassle, and most people don’t bother to do it because they think the small financial savings are not worth the inconvenience.
A timer can easily be fitted to most electric hot water heaters to turn the system on and off at the desired times of the day. This will make the most significant difference if you are on a time-variable pricing tariff with your supplier.
A cost will be associated with fitting a timer, which will be greater if you get a contractor to do it for you. Whether this is worthwhile is a personal decision based on your circumstances and priorities.
For more ideas on how to save energy and money in your home, read our article, “How To Monitor Your Home Energy Consumption (With Best Products).”