Losing Pressure & Water - modern central hearing system

[CSutton]

Hi all,
We live in a 3 year old house and our central heating/water system keeps losing pressure from what appears to be a pipe in our airing cupboard (you can see the water passing through the attached 'bulb' in the attached. The red valves when twisted eject further water. Why is the water escaping? Any help would be appreciated. Thanks, Chris

 

[Madrab]

Don't play with the red valves, they're safety valves for both your central heating and unvented hot water cylinder.

You need a UHW (G3) qualified engineer in to service the cylinder.

 

[KenGMac]

CSutton, good evening.

Following on from post by Madrab, with some really good advice that must not be ignored?

How often do you have to re-pressurise the system?

One area that allows a pressure loss is that when vacuuming, the machine hits a C/Heating pipe and can cause a very small leak?

Suggest you have a close look at all the rising pipes to all the radiators? it is sometimes a tiny leak at this point dribbling on to a Carpet, and can be difficult to spot, no water ponding Etc. it can be an easy fix.

Ken.

 

[CSutton]

Thanks for the advice but no pipes go into the floor but into the walls quite high up so it's not possible to knock them.

 

[oldbuffer]

Most of your pictures show an unvented hot water cylinder and its safety devices. The large red expansion vessel in the final picture is likely to be for the central heating, as those for hot water are normally blue or white.

If the hot water cylinder is a Heatrae Sadia MegaFlo, it has an internal air space designed to absorb the increase in pressure when the water in the lower 3/4 of the cylinder is heated. Over time this air space becomes full of water, and needs to be reinstated. This can be done by the user without the services of a G3 registered plumber, and the instructions on how to do it are printed on the side of the cylinder.

If it does not have an internal expansion space, or the problem remains after reinstatement of the expansion space, then you will need a G3 registered plumber to fix it.

Whatever happens, these cylinders and associated controls should be serviced by a G3 registered engineer on an annual basis, as they have the potential to cause catastrophic damage if not well maintained.

 

[Madrab]

Just carrying on from @oldbuffer, as you have a white expansion vessel then that will probably govern the unvented HW expansion therefore this needs to be checked to ensure it's carrying enough pre-charge, if it has then there may another issue that is causing one of the safety valves (T&P probably)to open and letting water out through the tundinsh (wee black bowl/bulb thing).

Again - needs to be checked by a qualified (UHW/G3 professional)