9 - Immediately place the white plastic piece, washer and nut onto the threaded rods. Use an 18 mm open-end wrench to tighten, without forcing.

Identify your Zone Valves - they will typically be in the airing cupboard or close to the pump. A two port Zone valve is on the left and the mid position valve is on the right (below).

Centralheatingvalves explained

1 - Grease the sealof the 110 mm waste apdato so that the 90 degree waste pipe elbow fits easily. If you are gluing the PVC connection, use a straight glue-in 90/100 sleeve. For standard bowl placement, check that the height is 230 mm. Check to make sure the unit aligns with your marks. If necessary, adjust your measurements for the desired bowl height.

10 - Make sure the bowl is level. If necessary, adjust it by rotating the white plastic pieces. Install the plastic covers.

6 - Adjust the level by loosening the adjustment bolt on one of the feet using a 13 mm wrench, then tighten the screw. Make sure the screw is firmly tightened on the other foot.

2 Port zonevalve

8 - Apply soapy water to the connectors. Place the ceramic bowl facing the flush pipe, waste pipe and threaded rods, then push firmly until it touches the frame.

If your boiler is working nicely, but you have a problem with either the hot water or the heating not working, it could be your zone valve that is malfunctioning. In this article we're just discussing system or heat only boilers, not Combi boilers. If you have a Combi boiler and you don't have heating, or your heating goes on when run the hot water, your diverter valve could be faulty. This article is for customers who have a separate hot water cylinder.

7 - Place the other end of the hose in a bucket to catch the water, and then slightly open the faucet to check for water. Close the isolation valve. This operation flushes any debris out of the water connection to the cistern,

If you are happy doing some DIY, you can isolate the electricity and remove the head (the silver casing) and take off the motorised part of the zone valve. It's normally just two screws that need to be removed. Once the head is removed, using pliers, move the zone valve manually. Does it move freely? (it only moves a quarter / half a turn). If the valve moves freely, switch the electrics back on, and see if you can open the valve manually. Does the pipe after the zone valve get hot?

2 PortValve

When replacing zone valves, don't buy a no name brand. Just by Honeywell or Drayton. A good valve last many years and the hassle of having one go faulty is not worth the £20 savings made from buying a cheap zone valve.

Again, switch off demand for hot water, create demand for central heating, and then feel if the pipe coming off the connection marked A is getting hot. Again, if the pipe is not getting hot or indeed your boiler does not operate, it most likely is the motorised head that is faulty.

3 wayHeating valve

1 - Using your Spirit level, draw a vertical line that crosses the center of your waste pipe. Measuring from the floor, for a standard bowl placement at 400 mm from the floor, draw a mark A at 1 m and a mark B at 1.08 m. If necessary, adjust your measurements to match your own desired bowl placement.

6 - Make sure the isolation valve is closed and open the main water supply. Make sure the isolation valve connection is water-tight.

3 - Attach the exterior part of the stop valve to your cold water connection using a 22 mm open-end wrench and a pipe wrench. This assembly must be made without using a seal.

2 - On your mark B, draw the holes for the wall brackets 235 mm to the left and to the right of the center of your evacuation.

If you have a mid position valve - the one that makes a T junction, one pipe goes to the hot water cylinder (marked B on the zone valve), and the other to the central heating (A). The pipe marked AB comes from your boiler, so it should be hot.

HeatingZoneValve

5 - Make sure that the unit is at least 230 mm from the wall, then mark the locations of the holes for the unit's foot brackets.

To test if your zone valve is working is very easy. Lets say your central heating is not working, but you have plenty of hot water. To test if your zone valve is working, switch off demand for your hot water (you can do this via the timer - set Hot Water to Off).

If you have 2 port valves, (you will have two or three of these valves, one for each heating zone and one for the domestic hot water) identify which one is connected to your hot water cylinder. Ignore that one, and feel if the pipe leading into the 'other' zone valve is getting hot (i.e. not the one going to your hot water cylinder). If it is, feel the pipe leading from the zone valve for heat. If there is no heat after the zone valve then it could be either that the motor is faulty, or the valve is stuck. It could also be that the boiler does not switch on.

4 - Secure the cistern in to the frame. First place the elbow of the flush pipe on the frame, and then press down on the cistern to clip it into place.

Centralheatingmotorisedvalvehow it works

4 - On the back of the actuator panel, attach the air button by rotating it completely, then connect the blue tube to the mechanism.

4 - Put the unit into place and check the position with respect to the water supply and waste pipe. Maneuver the 90 degree waste pipe elbow according to your installation (horizontally or vertically). If necessary, adapt the connection using PVC piping.

10 - Adjust vertical alignment using the screws and spirit level. Use a 13 mm open-end wrench to tighten the screws. Close the metal clips to lock the screws. Finish by placing the plastic clips over the rod.

9 - Place the fixation brackets on the threaded rod, with the clips open. Secure the brackets to the wall using a 13 mm open-end wrench.

4 - Measure the space between the marks on the pipes. Carry this measurement over to the end of the pipes, adding 5 mm, and then cut off the end.

Congratulations, you have finished installing your new GROHE product. Check our other installation guides and discover all of our products on grohe.uk/com.