Boiler at very high pressure

[kiranbp]

I noticed earlier that the pressure gauge on our boiler was in the red. Now on using a hot tap the pressure increases very quickly...going to about 3.8bar (I haven't used the tap for long because of this). The pressure then fairly quickly returns to 3.4bar but will not go any lower..is there a way to release some pressure safely? Or should it just go down in time?
Boiler is a Valliance ecoTec plus 837.
Thanks in advance!

 

[emphasis303]

if you have a drain tap on the underneath of your boiler, should be a big red knob and there is a drain pipe already fitted just slightly turn this to let some water out, this should release some of the pressure, if you dont have a drain pipe already fitted then i would do this unless you know where the water is going to come out from and you have a bucket handy. this works for me if i put the pressure up to hgh for my vaillant

 

[bengasman]

Release some water from draincock to about 1 to 1.5 bar. The draincock is underneath one of the rads normally. NOT the big red knob underneath the boiler