Help / FAQ's
If you have a question or want to know some tips or helpful hints, then read on . . . . . . . . . . . .
  • If, in the summer time, the valve does not open - what do I do ?

The air temperature (and of course the pipe surface as well where the temperature is actually measured) in the height of the summer could be from 24 degrees upwards. If your preferred temperature is set to anything below the current air temperature then the Hydrosave will sense that it has nothing to do, as the desired sensed temperature is already higher than you have asked for. To check this, set the preferred temperature to 36 degrees or so (at least 6 degrees higher than the current air temperature), operate the Hydrosave and record that the valve opens as expected until the hot water arrives. Then re set your preferred temperature to a few degrees above the expected maximum air temperature for the time of year. In order to check the temperature the Hydrosave is reading, look in the user manual page 7 and put the Hydosave into MODE 6. To download a copy of the installation manual click here.

  • Do I have to use copper pipes ?

No - but there has to be a 15mm (electrically earthed) metal pipe of some sort near the valve for the temperature probe junction box to clip onto, so that the heat of the arriving hot water can be passed quickly to the probe tip to be monitored by the control unit. Plastic pipes do not heat up quickly enough.

  • Does the kit come with the pipe that goes out into the garden for storage ?

No you can get a 1/2 inch standard hose pipe from your local garden centre or DIY store.

  • What do I do if I can't install it myself ?

The best solution to this is to contact your local plumber who will be perfectly qualified to install it for you. The installation of the HydrosaveOnline kit should take no more than 2 hours and in most cases less than this.

  • Can I use the HS300UK, HS300EU or HS400UN units in my bathroom or shower room ?

No as these are mains powered units (they plug into the 240V or 110V wall socket) and regulations prevent mains powered units from being used in these rooms due to the chances of electrical shock (apart from electric shavers, the wall supply for which is made with special electric shock prevention safety features which normal sockets do not). Use the HS200UN battery powered unit instead, which is designed for these rooms.

  • Is it easy to replace the batteries in the HS200UN and HS100UN units ?

Yes just unscrew the lid and the universally available standard 9 volt PP3 battery just unclips from its holder allowing the new battery to be easily clipped in its place.

  • Is it easy to attach the self cutting tap to the copper pipe ?

It is best to get hold of an old piece of 15mm copper pipe to practice on first if you can, as with trying out anything new in a test situation. We have carefully chosen a self cutting tap that has a hinged base (or boss - the bit that clamps around the pipe) so that you only have one screw to worry about. The types with two screws drove us wild with frustration in the early days of development, which is why we sourced an Oracstar type with only one screw to make things easier for you. Decide on the position. Ensure that the concave rubber washer is seated against the inside front section of the hinged clamp, as this provides the seal to the pipe. Leave the rotating tap section in the boss by about three turns when you clamp the boss around the pipe. Otherwise we found it tricky to start the screw thread of the rotating tap taking up in the boss. Attach the hinged clamp (boss) to the supply pipe with the tap assembly facing forward and being accessible. Secure into position by firmly tightening the slotted bolt. Ensure that the tap is fully turned off. Screw the tap section further into the clamp in a clockwise direction. While doing this ensure that you do not cross thread. This need only be done by hand as there is only a minimum of resistance when the cutter goes through the copper pipe. Use a spanner to tighten the locking nut. Dont forget that we recommend that you first turn off the mains water supply cock.

  • What happens to the bit of copper pipe that is cut away inside when you rotate the self cutting tap ?

Our tests showed that most of the time a small section of the edge of the round piece stays attached to the copper pipe in a sort of hinge form. The cut away round disk then just hangs inside the pipe and the normal water passes right by with no trouble. If the small round cut section falls off, it invariably remains inside the pipe nearby due to its weight (if on a horizontal pipe) or falls to rest (on a vertical pipe).

  • Won't the internal metal cutter part of the self cutting tap rust and block the entrance ?

No - We though of that one and chose a self cutting tap with an internal stainless steel cutter (i.e. it won't rust).

  • Will the valve and temperature probe junction box fit behind my washing machine or dish washer ?

We have not had any problems in this area as the valve and junction box are quite small and take up little space. The water pipe and low voltage cables (12V dc max) are flexible enough to be pushed into nearby spaces to get them out of the way.

  • Do I have to take the white control cable through my kitchen work surface ?

This really depends on the design on the kitchen units you have. You may be able to take the cable along the back edge of the work surface, around the end of the work surface and through the side of the end floor mounting unit and back under the work surface to the hot pipe underneath the hot tap. You might even find a small gap somewhere to poke it through.

  • How do I use the Hydrosave unit with my shower ?

A lot of shower installations have hidden pipes that you won't be able to get to. Think about connecting the HS200UN to the bathroom sink hot pipe which should be more accessible. You will then save the cold water up to that point and unless you know how your pipes are connected to the shower and where they come from, there is a good chance that you will only have a short run from there to the shower itself. This is not applicable to electric showers that use a cold water supply only.

  • Can I use the HS200UN with my bath ?

Yes, but remember that you will be putting cold water into the bath anyway to get the temperature right. If your bath is a long way away from the boiler or hot water tank and you always run off the cold water first, then the Hydrosave unit will save you this wasted water. The valve and temperature probe will probably be placed under the bath with a small exit hole drilled into the bottom corner of the baths front cover, to allow the control cable through.

  • What tools do I need to use to install the Hydrosave unit ?

Normal household tools:- small flat blade screwdriver, maybe a hand or electric drill with 4mm drill bit if you want to pass the control cable through an obstruction (work surface, bath or sink front cover etc.). To pass the outlet pipe put through the wall, you will need a 18mm masonry drill bit with a reduced shank (the part that fits into the drill's chuck - most drill chucks accept up to 13mm bit shafts. You can buy an 18mm one from our HydrosaveOnline shop). Make sure that the bit is long enough to go through the wall before you buy it.

  • How do I get the water outside to store ?

The easiest and best way is to go straight out if you are working at an outside wall. The best piping method (and cheapest) is to use a cheap garden hose poked straight through the wall. Don' forget that walls are quite thick, maybe 8 to 12 inches (but could be more depending on the age of the house) and you need to survey and plan your pipes exit route and record anything you don't want to damage when drilling (18 mm hole is best), before you start the installation. Every house is different which is why a plan is very important. Don't forget to seal around the exit point with some form of sealant to stop rain water ingress.

  • How far can the storage butt be from the Hydrosave unit ?

Quite a long way. Certainly to the bottom of the garden in a typical suburban house (a hundred meters or so). The top of the storage butt must be around 6 feet below the hot water header tank, in order to get a reasonable flow rate, or if you have a combination boiler then really anywhere, as it is the water mains pressure, rather than the gravity feed in the header tank situation, that makes the water flow.

  • How can I get the stored water to go into my toilet cistern ?

Make sure that the bottom of the storage water butt is at least 18 inches above the level of the top of the toilet cistern in order to get a reasonable water flow rate. Take a hose pipe from a tank connector inserted near the base of the butt to the water input (of the float switch) in the toilet cistern. Your local DIY store will help you out with the adapters that you need to convert from hose pipe to threaded connector at the cistern where the water goes in. Remember that you may well want to have a hand valve system (2 single valves or a changeover valve) to enable you to change from stored water to mains water in case you run out of stored water. Again, your DIY store can provide the necessary push in pipe fittings and hand valves that you will need. If you have trouble with this then email us at with your problem and we will help you as best we can.

  • What can I do if I can hear and feel that the valve is operating but it wont actually let water through ?

Firstly change the battery if your model uses one (HS200UN or HS100UN). The valve we use is used in many other applications worldwide and has a proven operation (which is why we use it in our system). Inside the valve there are two specially placed small holes in the rubber diaphragm that opens and closes to control the water flow. If one of these gets a small foreign body, like lime scale, stuck in it then the valve will not operate correctly. Lime scale can fall off the inside of a water pipe and is more likely to be present in hard water areas. The solution is to carefully take the valve apart, having first turned the isolating tap off and removed the valve which is extremely easy to do by unclipping it from the pipe it sits on and unscrewing each hose connection end. There are only 3 normal Phillips type screws to remove the white body. Inside there is the operating plunger and the diaphragm. The two small holes in the diaphragm can be visibly checked for lime scale blockage and any blockage can be removed by blowing through the hole or carefully using a sewing pin or small needle. Once the valve is reconstructed and reconnected then all should be well. The other way of fixing the problem is to contact us first to see if we can help over the phone or if not you can send the valve to us and we will clear it for a small standard fee (plus return carriage) and send it promptly back to you.

  • Can it be used where a pump / pressure sensor system provides the hot / cold water pressure ?

Yes - as long as pressure is maintained in the hot water pipes, then the saved water can be used as we say or be directed, if required, via additional piping back to the header tank and reused. In a system that uses gravity to provide the water pressure, reuse is not possible without additional pumping and control. In a system that uses the water main to provide the pressure at the hot tap then redirecting to the header tank is also possible. With reuse be aware that if the cold tap is fed from the same header tank, then previously cooled hot water will be present at the cold tap as this water has already passed through the heat exchanger (hot storage tank or combination boiler).

  • How do I get the outlet hose onto the hose connector ?

Danger of scalding ! Only a competent adult should follow this procedure ! Place boiling water in a coffee mug. Place the end of the garden hose into the boiling water and leave for approximately 1 minute. This will soften the hose material. Remove the hose from the mug ensuring that you do not touch the heated hose area or drop hot water onto your hand. Immediately push the hose, forcing if necessary, over the end of the hose connector. While pushing, rock the hose end up and down and the hose will slide up the connector. Ensure that approximately 1.5 cm of hose covers the hose connector. The hose will become stiff again within 2 minutes in free air as it contracts onto the hose connector. The clip is a must to keep the hose end in place.

If you have any other questions that we can add to this FAQ list, then please email them to us and after replying to you, we will include them here.

To enter the Hydrosaveonline shop now click here or for product selection click here.