Worcester 24i - High Increasing Pressure

[tom2007]

Hi,

I have a Worcester 24i combi boiler. A few months back it started loosing pressure, so I topped it up but it kept dropping, I checked all there are no obvious signs of leeks. Recently I installed a towel rail once it was installed and all was up and running I bled all of the radiators. The pressure now doesn't drop as much but it still falls but only by about 0.2 of a bar over a week or so. However now when I turn the heating on the pressure increases a lot quite quickly. It rises by about 2 bar in 20 mins or so. Its been upto about 3.4 bar, I've been too scared to leave it any longer. I'm no expert so have only been going on advice - ie bleed the system etc. When the heating isn't on presure is usually around 1 bar
Has anyone else had any experience of this, or has anyone got any ideas? Any help would be really appreciated

Thanks
Tom

 

[fasea]

Though no expert (i do have the same boiler though) I would think the reason for the loss of pressure is due to a leak through the PRV (pressure relief valve). This is a valve which has a red button on it, it should be connected to a short pipe coming outside of your house. Check this for water, if it has some there's your leak.

The increase in pressure in heating I believe means you don't have enough air in the expansion vessel, so when the water is heated theres nowhere for it to expand so the pressure goes up, when it hits 3 bar the already mentioned PRV will open meaning your leak water.

I think there is a guide on how to re-pressure the expansion vessel in the sticky somewhere .....