Plumbing Question.

[BigDogsWang]

There is a small white box attached to one of my cold water pipes in the airing cupboard. It is about 3 x 3 inches in size, and has an Electrical cord coming out of it, and it seems to connect to a copper pipe with some sort of device going into the actual pipe.
For some time the carpet in the airing cupboard has been wet, and the Central Heating system keeps losing pressure. The other day I found that this white box was very lose and dripping water. I tightened it up and the Central Heating is now working better than ever and not losing pressure. However, it is still dripping water quite severely.
Can anyone tell me what this box is / does, and can I replace it myself easy enough?

The box is made by 'Danfoss'. I would post pictures but I can't see how to.

[Baldric]

Most likely a water softener / conditioner.

[Old_Geezer]

You post onto a host site then post the link to the file there, here.

Is it a c/h valve ? Whatever it is a call to a competent plumber should sort the leak.

[BigDogsWang]

I googled water softeners but it's not that. However I did find what it was http://www.plumbcenter.co.uk/en/heating/domestic-controls-valves/danfoss/danfoss-randall-hp28b-2-port-valve-hpa2-28-mm-15644

Does anyone know if this is an easy thing to fit? Indeed, does it mean it's leaking, or the pipe that goes into it?

[KARL]

Although you don't openly say it, this device is on a heating line. I believe it must be a zone valve. These open and close for circulation of heating water, usually triggered by a thermostat somewhere. What is leaking is the valve as a separate part from the actuator which is the box marked Danfoss. My suspicion would be that if you took the actuator off then there would be a leak around the pin which then is visible - that seal can be replaced or alternatively the entire valve body can be replaced. They can be replaced by isolating that part of the circuit or else draining the entire system. Unfortunately, it is very common for plumbers to install heating systems without isolation valves that enable separation of branches for maintenance purposes. Unless you are fairly competent in plumbing (mind you none of it is very challenging) then you might be better to employ a plumber.

[BigDogsWang]

Thanks Karl. There is a lot of rust behind the box where it joins the pipe, so that sounds like the problem you say. I have an extensive tool kit and I have done quite a bit of Plumbing before so I might give it a go :)

[hammerman]

Could it be the motorised valve ?