Install Pump in a Loft
Installing a pump in the loft or above a hot water cylinder is not the best position for a pump for many reasons, so if you have a choice then fit the pump at the base of the hot water cylinder. If you are going to install the pump in the loft then these instructions are the best way to deal with the installation and can be followed for most makes and models of pumps.
I have based this how to installation guide on installing a Salamander CT50 twin Shower Pump.
These instructions are assuming that you are installing a twin shower pump, but the same instructions will apply for whole house pumping and single impellor pumps.
The pump must in all cases be installed at least 600mm from the bottom of the cold water storage tank to the top of the motor/impellor casing of the pump.
So if you do not have the ability to have a raised cold water storage tank in the loft then fit the pump above the cylinder but below the ceiling.
Cold Water Supplies and Connections.
First rule of thumb is to make sure that you are storing enough cold water for the shower, 225 litres or 50 gallons is normally adequate for most shower applications.
The installation of the water supply from the cold water is straight forward, first use a separate 22mm outlet connection from the cold water tank on the opposite side of the tank to the float valve (to make this connection use a 22mm compression tank connector).
It is good plumbing practice to next use a 22mm full bore isolating valve, always fit ways of isolating the water supplies both at source and locally to the pump you are installing.
This supply can now feed the pump inlet, if there are no isolating valves fitted to the pump anti-vibration couplers then fit them just prior to the pump.
It does not matter whether the pump is 22mm or 15mm connections by supplying the pump with a 22mm supply with full bore valves there will be no restriction on the suction side of the pump.
Hot Water Supplies and Connections.
There is only one way of connecting to the hot water cylinder correctly where the pump is higher than the outlet from the hot water cylinder, you will have to use have separate connection that is not restricted and ensures that little air can get into the pump impellors which will if excessive damage the pump.
With this in mind you will need to use a dedicated flange to connect to the side of hot water cylinder a 22mm non stop Essex flange will give the least resistance. You will then need to plumb in an anti-gravity loop, this is a pipe that bends towards the floor by a minimum of 250mm in 22mm (350mm in 15mm). If you are using our instructions for another brand of pump other than Salamander then use a 350mm anti-gravity loop in 22mm. Make sure that you fit full bore isolation valves to the hot outlet from the cylinder either before of after the anti-gravity loop.
Flush pipe work prior to connecting to the pump!
Now connect to the hot supply pipe to the inlet of the pump, if the pump is not in the hot water cylinder cupboard then you will need to fit another full bore isolation valve just prior to the pump.
Once you have connected the supply pipes to the pump it is now time to prime the pump, with the electrical supply to the pump off run one bucket of water out of the hot and the cold side of the pump until the water has run clear and there is no apparent air.
You can now run the pipes to the shower valve, if the pump is a 22mm pump then it is best practice to run 22mm pipe close to the shower valve, and if the pump is 15mm connection then run your pipe in 15mm. You will need to fit manual air vents in the highest pipe position, the air vents and pipe work should not be any higher than the cold water outlet from the cold water storage tank.
It is important to make sure you install a non return valve on the hot outlet side of the pump.
There should be isolating valves fitted in an accessible position close to the shower valve for servicing again flush pipes prior to any connection to a shower valve.
That’s it happy showering………..