I have a flat in Scotland, UK. We live on the 2nd floor. We have been here for about 18 months and we have a (new-ish) Combi boiler holding a static pressure measurement of around 1.6 bar.
Boiler water pressure indicator increases by about 0.2 bar when central heating is on.
We usually have no need to check the pressure and we found to our surprise a few days ago that the hot water (washing) was not heating, checking the boiler it had a stated pressure of only 0.3 bar, and so the boiler was not firing.
The water flowed out the taps are at a suitable speed.
I hooked up the repressuring inlet tube and raised the boiler pressure to 1.9bar. This is the first time we needed to do this in 18 months.
From that day, I have been keeping an eye on the stated pressure of the boiler -- and the pressure is decreasing by about 0.2bar a day, right now it is 1.1bar . There has been a little central heating usage in the last few days (1-2 hours only) but I'm curious as to why the pressure seems to be dropping so persistently and if this cause would bring it down to under 0.5bar as before.
- We live in Scotland. The water does not contain limescale.
- I have extensively checked all visible pipes and no indication of any leak was found.
- Tap pressure hot/cold are roughly equal, cold tap pressure is not an issue.
- We have a new (18 months ago) Combi gas fired boiler fueling hot water and central heating.
- My only point of pressure measurement is the boiler display which is dial rather than digital.
- Radiator heating circuit is set to be turned on manually so we never have the heating on without doing so ourselves.
- Boiler is "Logic Combi ESP1 30". Boiler was installed new at property purchase.
Other Q&A on here:
I have read Low water pressure which sounds similar but the question deals with a lot of (technical?) stuff I don't recognise (their pressure guage for instance). I also viewed and a few similar posts but which seem to deal with fast/sudden pressure drops rather than gradual persistent pressure drops over time.
It feels like something's changed because previously this has never been a notable issue and certainly pressure has never fallen below 1bar in the last 18 months.
What else could/should I be looking at/for in order to try and establish the cause of this?
How can I fix this if needsbe?