Yes, you can often replace a shower without changing the pipework, especially if the new valve is a like-for-like swap. Whether it works depends on the pipe positions, the type of connections and the water pressure in your home. When these match, the job can be fairly simple.
Why Pipe Positions and Centres Matter
Most exposed mixer showers, including bar mixers, connect to two pipes coming out of the wall, one for hot and one for cold. The distance between these two pipes is called the centres. Many exposed bar valves are designed to fit common standard centres, so a new valve can often line up with the old pipes.
Adjustable fittings on the back of many valves allow a little movement, which can help with small differences. If the gap between the pipes is very different, or the pipes come out at an odd angle, they may need to be adjusted. It is also worth checking which side the hot supply is on, because most valves expect hot on one particular side.
Pressure and Hot and Cold Supplies
The new shower has to suit the water supply you already have. In some homes the hot and cold supplies are balanced, meaning both come at a similar pressure, such as from a combi boiler or an unvented cylinder with mains cold. In others they are unbalanced, for example low-pressure hot water from a loft tank with mains-pressure cold.
Some mixer valves cope well with unbalanced supplies, while others need balanced pressure to give a steady temperature. If the new valve does not match your system, you may need extra fittings, a different valve or changes to the supply. A quick check of your hot water system before you buy can save a lot of trouble. If your flow is already weak, our guide to water pressure problems may help explain why.
Valve Compatibility and Access
A concealed valve is a different story from an exposed one. Concealed valves sit inside the wall, and each brand often has its own body and fixing depth. Replacing one with a different make can mean opening the wall to change the body, even if the pipes stay where they are.
Sometimes it is possible to replace only the cartridge or the controls of a concealed valve rather than the whole unit. This can avoid disturbing the tiles. Good access, such as a removable panel, also makes any swap easier.
When the Pipework Does Need Changing
Changes are usually needed if you switch from a concealed valve to an exposed one, move the shower to a new spot, or upgrade to a pump. Old, corroded or undersized pipes may also be worth replacing while the wall is open. A plumber can tell you what is needed as part of a shower replacement and whether your current pipes can stay.
If you are thinking about swapping your shower in Swindon, Emergency Plumber Swindon can take a look and explain your options. Call 01793 569521 for friendly advice.