boiler advice please

asparagus1968

hi, I have a vaillant turbomax plus.its running fine but the pressure gauge is between 2 and the red area.
online I've found what to do if the pressure is very low,but not if it's high.
TIA

Seronera

The key question here is what it reads when the system is cold. When cold the pressure gauge should be on 1bar or just above 1, but certainly not higher than 1.5bar.

If it then proceeds beyond 2 bar and heads towards 3 bar when the system is hot or getting hot, then that is indicative of an expansion vessel that has either lost its air pressure or in extremis has failed.

The boiler needs draining (not the whole heating system) and the expansion vessel needs re-pressuring to the required pressure with the boiler drain still open to expel excess water. I would prefer to see a gas professional do this job even though there are some out there quite competent enough to DIY it.

Afterwards the pressure gauge should be much more stable as the pressure vessel air 'cushion' has been reinstated and allows for the expansion of the system water as it heats up. It is a safety matter, hence my preference for a professional to do it.