Baxi instant 105e combi pressure to high

[Christian]

Hello, i have a baxi instant 105e and the pressure relief valve is letting water out of the external over flow pipe when ever the water pressure goes over 3bar.. i have had an external expansion tank fitted about a year ago. i have just fitted a new relief valve and within 10 minutes the pressure had risen to 3.5 and there is now a very fast drip out of over flow pipe. what is causing the pressure to rise in the boiler to cause the pressure relief vave to blow ?? pease help !!

 

[jtsplumbing]

1. Could be that new external tank wants recharging.
2. Filling loop is letting by
3. Pin hole in domestic heat exchanger.

 

[folwlerg68]

is your filling loop connected? if it is then make sure isolating valve is turned off and disconnect one end off filling loop. then you no it cant be letting by and filling system.

 

[southcoastboile]

there not gsr :banghead:

 

[Christian]

Thank you for that, pipe is letting water through so i have just brought a new one, expansion vessel is at 2 bar

 

[Christian]

Is 2bar correct for my external expansion vessle ?

 

[folwlerg68]

between 1bar and 1.5bar. forgot to mention filling loop should not be left connected only connect when system needs topping up.cheers grant.

 

[Christian]

The boiler is now working great thanks everyone who helped, isoating valve was stuck half open and and siezed soid. my vessel pressure is correct now aswell. :clap: