Hot Tub Pump Installation & Wet End Rotation

How do I fit my new hot tub motor?

When we supply you with either a new motor or a wet end, you will need to know how to connect the wet end to the hot tub pump motor. If you have any concerns about this email us on info@poolandspacentre.co.uk

Undo faceplate. With a screwdriver undo the screws on the faceplate of the pump wet end.

Release faceplate.

This bit can be a little bit tricky as the plate is sealed to the wet end body. Carefully wedge a thin flat-headed screwdriver into the joint. It is easier to separate the faceplate around one of the screw holes (as pictured) because less damage will be caused to the seal between the plate and the wet end body. Move around the plate with the screwdriver, slowly levering it off.

Take out the impellor. Use some gloves as it could be sharp due to wear

Keeping all of the bits together, take out the impellor unit. Note how the wear ring sits on the impellor to avoid confusion when re-assembling.

Thread the wet end body over the motor spindle.

Make sure the bolts are fastened nice and tight.

Insert impellor and begin to screw it onto the spindle.

Hand tighten the impellor.

If the spindle has a square section that facilitates a spanner then tighten the impellor hand tight. Do not overtighten.

Tighten with a screwdriver.

If the spindle is circular and cannot be tightened with a spanner. Then tighten using a screwdriver at the rear end of the motor.

Return the faceplate to the impellor making sure it fits true. Reposition the faceplate and retighten the screws.

Before fitting the pump to the hot tub wrap a plastic bag to the intake hole with elastic bands and fill it with warm water. This isn't fail-safe as it will be under greater pressure when in operation, but it will indicate if there are any major leaks.

Removing your old pump.

SWITCH OFF THE POWER AT THE RCD AND/OR THE MAIN PANEL CIRCUIT BREAKER or FUSE BEFORE INSPECTING OR INSTALLING SPA PARTS. Do not attempt to install any powered spa part or undertake any electrical repairs unless you are qualified/competent. If you have even the slightest doubt, call a spa technician or electrician before proceeding.

Certain spas have two gate valves installed at either side of the pump. If so, close these valves (Valve handle Up = Open, handle Down = Closed). If no valves are present, drain the spa.

Disconnect the pump's electrical plug from the side of the control box. Remove the mounting screws from the pump base bracket. Disconnect the two unions from the pump suction and discharge. There will be a little water spillage. Disconnect the bare copper wire from the pump's ground terminal.

Take off the wire of your old spa pump.

Unscrew the top plate off the box, unclip the capacitors, and then unscrew the whole plastic box.

Note the wiring configuration. FYI some pumps have a wiring diagram on the underside of the capacitor box.

It is important that you note the wiring configuration on your old pump so it exactly replicates that of your new pump. Note the wire colour and position. There are four wires on a two-speed pump and three on a single-speed pump.

Two-speed 230V pumps have 4 wires: red, black, blue, and green. Red is normally low speed, and black is high speed. The blue wire is neutral and the green is earth.

Connecting new pump.

Reattach the bare copper bonding wire to the pump grounding terminal. Now place the pump in place, carefully aligning it to the union connections. Start the base mount screws, but do not tighten them yet. Hand tighten the unions. Do not use a wrench. Tighten the pump base screws. Not always essential as they are known as fixing bolts for transporting the tubs when in the upright position.

The unions are compression fittings that should be correctly aligned with the male wet-end threads to allow the integral O-ring to seat properly.

Flooding the Pump.

After installation and wiring hookup, but prior to powering on the spa, make certain to open the gate valves (if so equipped) to flood the pump and prevent an airlock. If you have drained the spa, refill it with fresh water.

IMPORTANT: To release remaining air pockets by loosening the pump unions until all air has escaped (you will hear the air escape)-- then hand retighten. Do not run a pump dry as this will cause damage and void the warranty.

Testing and Inspection.

Inspect the installation to verify that everything is properly connected. Mop up any spilt water. Reconnect power source. Operate the spa for a few minutes and observe for leaks or airlocks. Replace the equipment bay access door and you have just replaced your spa pump CONGRATULATIONS!!.