Expansion vessel has lost its air. It would need draining of water and re pressurised to 0.75 bar. Also sounds like the plate heat exchanger is scaled up causing temp in shower to fluctuate.
Sounds like you have two totally seperate issues. The locking out of the burner is an ignition problem ie oil or ignition. Check all filters. Check oil is good (no water). Check no leaks or blockages in oil line.
Check spark electrodes are not breaking down (erratic spark) and check gap. Check...
Since your meter appears to measure in m� (metres cubed), we don�t have to worry about converting to metric, however, we do need to convert it to a standardised volume. (Volume varies with pressure so before any calculations are done, the actual volume you have used is converted to...
rates of units vary between companies and area. i would base 1 unit to 4 pence as an average. Then of course you have an A rate and a B rate, the B rate being less at around 2.5 pence.
sounds like something is leaking inside your boiler and consequently that is why your pressure is dropping.The water pressure has nothing to do with how much gas the boiler uses or how efficient it is
you need to get the leak sorted
this depends on whether it is over pressurizing when hot or cold. If when cold, filling loop letting by or rarely heat exchanger faulty. if it is only when hot then either undersized expansion vessel for water volume or expansion vessel failed.
You need to remove all the baffles from the boiler, clean them and check they are in good condition and that they are seated correctly. Clean combustion chamber and flue ways. Clean magic eye.Fit new nozzle. Reassemble.
Set oil pump to 100 psi. Fire boiler, take smoke test, bearing in mind you...