Expansion tanks are normally installed above the water heater on the cold water line before it enters the water heater.
Expansion tank installed on hot water side.
In normal operation some water goes into the expansion tank each time a new tankful of water is heated.
The expansion tank serves as a backup system to prevent overworking your plumbing.
An expansion tank is generally installed directly above the water heater by means of a tee fitting installed in the cold water delivery pipe.
The expansion tank is usually installed horizontally though it is acceptable to install it vertically if it is necessary because of space limitations.
The device contains the air membrane diaphragm usually made of rubber which is pressurized with air on one side while on the other side is water from home plumbing.
However they can really be installed anywhere on the cold water line prior to entry into the water heater.
It would actually work on either side since they are both within the system so to speak per watts the tanks are rated to 150 psi 200 degrees.
Having an expansion tank helps prevent dripping faucets and running toilets by keeping the extra built up pressure in the system from reaching the fixtures and prematurely damaging them.
Install an expansion tank on the hot side.
If the expansion tank is on the hot side then the next time someone uses hot water the now cooled water will come out of the expansion tank and head for the open faucet before fresh hot water from the heater tank gets up there this lengthens the time and increases the water waste waiting for the water to get hot.
Expansion tanks aka thermal expansion tanks are essentially safety devices to help you minimize the risk of damage to your hot water tank they are an add on to your existing hot water heater and are often installed on the water supply pipe to the water heater normally this is on the wall next to or very close by your hot water tank.
Water expands by roughly 2 as it heats up from 50 f to 120 f.
Be sure the tank you replace it with is designed to work with hot water.
Direct vent systems this also comes into play at vent terminations near operable windows etc.
The expansion tank or vessel is designed to receive a volume increase of the heated water reduce the pressure and protect the system from failure.
The tank has two sections that are separated by a rubber valve.
This ultimately protects it from damage.
If using a tank for hot water expansion it can be on the cold feed line but must be after any check valve.
You install the expansion tank down the line from the inlet valve that sends hot water into your home.
When your water thermally expands a water heater expansion tank prevents unwanted increases in pressure.
The cold water line is the typical place to have one for a well pump pressure system but that is presumably not the situation you have if the current tank is on the hot water side.
If there s no check valve it can be anywhere on the cold side.
The excess water volume instead of causing too much pressure on the plumbing rushes into the expansion tank and lowers the pressure in the water heater to safer levels.