If it seems like your water is taking forever to heat up when you turn it on, you might be worried that you have a major problem with your water heater. Before you call a repairman, however, it’s worth doing some DIY troubleshooting yourself. In some cases, you can fix your slow hot water problems yourself, with minimal expertise.

Here are four ways to fix the simplest causes of slow hot water, and some advice on when to give up and call a professional.

The number one reason your hot water pressure suddenly drops is because a valve has accidentally been left partially closed or has been bumped partially closed. Sometimes you can accidentally open a valve while cleaning or moving things near the valve without realizing it. If you have a faucet or fixture that is experiencing slow hot water, check the hot water valve connected to the sink, shower, or other fixture. To make sure it is fully open, turn the hot water valve counterclockwise or in line with the pipe if it is a lever.

If the hot water is slow throughout your home, check the outflow valve on your water heater. Make sure it is fully open, with the lever aligned with the outflow line. If you have a water pressure gauge or other internal valves that control the flow of water to (or from) your water heater, this could also be the source of your slow hot water problems.