Sudden Surge of Cold Water

When water in your shower suddenly turns cold,  it can be for a few various reasons. If you have a smaller hot water heater, you could have used all the available hot water. If this is the case the water will turn cold and cold only. If you experience a sudden surge of cold water that only lasts for a few moments, it is likely that someone else in your home is using the hot water. This can occur when an appliance such as the washing machine or your dishwasher is running or when someone is running hot water from a faucet in another bathroom or the kitchen. This occurs for the same reason of you getting a blast of hot water when the toilet is flushed. Ahhh, this is annoying! The available hot water is diverted to another source first and then leaves the shower with too much of the cold water portion and no hot water that it can mix with.

Sudden Shock of Hot Water

The most common reason for that initial shock of hot water while showering is a flushed toilet. Because the toilet uses cold water to refill the tank, the cold water from your shower will be diverted to the toilet, leaving only hot water in the shower until the toilet refills. This can produce a blast of water hot enough to burn you or just want to turn your shower off or stop your shower early entirely. This typically happens in homes with trunk and branch plumbing. Trunk and branch plumbing uses a larger diameter pipe to carry the water the length of the home and smaller pipes to carry water to individual rooms or outlets, like the shower and toilet in your bathroom. Running the cold water from a sink can have the same effect as flushing the toilet.

Solutions

Solving the issue of getting shocked with hot water or getting blasted with cold water while showering doesn’t require any hard work.

The easiest solution is simply telling another family member to avoiding flushing the toilet, holding off on all other home appliances that use water and not to use the sinks at the same time.

If this absolutely cannot happen you have the option of installing a mixing valve in the shower will likely solve your problem. These mixing valves are made to keep the water pressure and temperature constant in your shower. This means that if someone in your household flushes the toilet or runs water while you are in the shower, the valve will detect the decrease in water pressure and automatically adjust the hot and cold water to prevent fluctuations in temperature.

Increasing the available water by upping the size of the trunk and branch pipes will also reduce the problem, but it will not be perfect. If you are having issues with blasts of hot or cold water in your shower, contact your professional local plumbers who are experienced and knowledgeable about all of your bathroom pipes.