Does anyone know anything about boilers? Help.

[Fairylea]

Before I call our plumber out (again) can anyone shed some light on this?

A few days ago I noticed the pressure was very low on our boiler (a Valliant eco tec). I used the little taps / valves inside to increase the pressure as I've done a billion times before (once every 6 months or so for the last 7 years we've had it). Never had a problem before but it started dripping and wouldn't stop! We called out a plumber and he replaced the filling loop and the little switches / valves.

When I turned on the heating last night the pressure went up very high and the unit was flashing and saying "2.8 bar" so I turned it off and the pressure slowly went down again. The photo is where it is at resting pressure - first thing this morning after being off overnight. Is this still too high? Should I drain more off (at the radiator)?

Are the other settings okay? I just want to be able to use the heating without the pressure going too high!

Obviously I will call the plumber back if I need to but if it's something simple I can fix myself I will. The plumber always seems to leave the pressure bang in the middle which is too high for our system!

Pressure should be 1 - 1.4bar when boiler is cold, it will rise 1/2 bar when the boiler is hot/running.

If your pressure is increasing more than this it indicates that there is a problem with the expansion vessel or the filling loop is letting by.

When the boiler is cold/off does the pressure increase at all? If so it would indicate filling loop either not turned off fully or letting by.

If the pressure only gets high when boiler running it indicates the expansion vessel. Check out side for the Pressure Releif Valve (if it's been put outside) if expansion at fault the PRV will let by and you will see water.

Your filler tap is still turned slightly on. Make sure it is switched off.

Sounds like classic symptoms of the expansion vessel losing its charge or failing.
You probably had to top it up because the charge was lost, and the filling loop problem was coincidental.
Either way you'll need to get the engineer back to look at it.

Thank you very much.