CT85 Xtra

There are multiple factors that will impact which is the best shower pump for your home.

Use our product selector tool to find the right product.

A gravity fed water system is identified by a cold-water storage tank, usually stored in a loft, and a hot water cylinder. These systems rely on gravity to force water around the system, with the height of the cold-water storage tank determining the pressure throughout the system.

Cold water is delivered to the cold-water storage tank from the water mains. Cold water from the cold-water storage tank is then supplied to the outlets around the system, such as taps, toilets, showers and baths.

The cold-water storage tank also feeds the hot water cylinder, where a heating coil from the boiler or immersion heater will cause the cold water to become hot. Once an outlet requiring hot water is opened, gravity will force cold water from the cold-water storage tank into the hot water cylinder, this will then force hot water out from the top of the cylinder, delivering hot water to the open outlet.

It is common for gravity fed water systems to suffer with low pressure, installing one of our gravity fed shower pumps can help to improve the pressure, click here to see our range gravity-fed shower pumps.

Gravity-fed water systems are either positive or negative head. Before choosing a gravity-fed shower pump it is important to know whether your system is positive head of negative head, click here for further information.

If you’re unsure which product you need read our guide to selecting the right product, or use our product selector tool.

A gravity-fed system is either positive or negative head. In a positive head system a water flow rate of at least 2L/min exists from gravity alone. In negative head systems the water flow rate is less than 2L/min.

When choosing which pump you need it is important to know if the system is positive or negative head as incorrect selection can mean the pump won’t work.

A positive head pump will only work in a positive head system and a negative head (universal) pump will work in both a positive and negative head system, so if you are not sure choose a negative head pump.

Click here to learn how to determine if your system is suitable for a positive head pump.

A positive head pump will activate when a minimum flow of water passes through the pump and out of the pumped outlet, such as a shower or tap, naturally (without assistance from the pump). The minimum flow rate required for our positive head pumps is 2 litres of water per minute (L/min).

You will need to measure the flow rate to determine if a positive head pump is suitable for your system. You will need to test all outlets, such as showers and taps, that are going to be pumped to determine if they have the required minimum flow rate of 2L/min. Watch our video to learn how to measure the water flow rate.

If you cannot measure the water flow rate, then you can check if the system is suitable for a positive head pump if there is more than 600 mm between the base of the cold-water storage tank and the highest point in the system after the pump.

If you are unable to achieve the minimum flow rate of 1 litre per 30 seconds from all outlets that are to be pumped you will need to install a negative (universal) head pump.

Single impeller pumps supply either hot or cold water, to single or multiple outlets. This can often be when the cold water is mains fed and the hot needs to be boosted to match this pressure.

Twin pumps have two impellers and are designed to supply both hot and cold water to showers, bathrooms and whole house installations.