CommunityCold Water Blast in Shower: How to Prevent?

Cold Water Blast in Shower: How to Prevent?

My home was built in 1980. The water supply is from a well water system.  In the room where it runs into the house, there is also a pressure tank and a water heater, both of which look to be from the late 80s.  During showers, there is a short, yet distinct pressure “spurt” followed by a blast of cold water, which definitely wakes a guy up in the morning!  What is the cause of this and how can I fix it? 

The Money Pit Answer
I'm happy to report that the solution to your problem doesn't involve replacing your water heater or pressure tank. Rather, all you likely need is a pressure balanced valve.  A pressure balanced valve maintains the ratio of hot to cold water regardless of what happens to the pressure in either line.  Currently, without the valve,  if you lose pressure in the hot water line, you get that burst of cold water.  With a pressure balanced valve, you'll experience a reduction in the water flow, but the ratio of hot to cold will be maintained - so no cold burst.