Worcester Bosch boiler pressure

andygb

The pressure was low on my 9 year old boiler last week so I re-presurrised it to 1.5BAR's.
However, tonight the pressure is in the low red zone below 1 BAR, so what kind of fault could that be?

Alex1983

Walk around your system and check for leaks, have a look out at the copper overflow pipe outside and see if it dripping.

Top back up to 1.5 and run the heating for 15mins and she where the pressure is then.

magn8p

It's either an issue with the boiler's expansion tank or with leaks in your heating circuit. Since it almost a 10 year old boiler, it sounds like an issue with the boiler - when was the last time it was serviced? Did the Gas engineer give you any advisories? If possible call the same guy as he can refer back to his notes and quickly diagnose what has gone wrong.

Also, check for the leaks - but 1 bar drop is equivalent to losing 5 litres and such a big leak would clearly visible, so watch out for obvious signs.

If you have a home insurance, you should be partly or fully covered for issues like this.

All the best.

andygb

Just a quick update.
I didn't have any advisories on the last service back in June, but the diverter valve motor was changed.
The pressure was low today (1 bar), so I took it back up to 1.5 bar and turned the rads on. The pressure then steadily climbed to just over 2.5 bar On the red zone) and has now dropped back to 1.5 bar.

Alex1983

You need your expansion vessel recharging or replacing.

pollypenny

When that happen in our house it was a leaking radiator pipe, ground level, caused by my over-eager hoovering.

I didn't spot it for a while as I was feeling around the bottoms of the radiators themselves.