No hot water can’t repressurise

[ForrestB]

Hi I desperately need some help please. We have an oil fed heating and hot water system that has decided to stop working today. Done the obvious checks on the oil, which is fine. But they system is below 1 bar pressure. So suspect this to be the main issue. However I can not seem to be able to pressurise the system. Therefore took one end of the filling loop off as pic shows and the isolation valves all work.

The valve next to the expansion value also work as when I turn this on it jets water out. What am I doing wrong or what could be the issue?

 

[Ben-gee]

When you turn the little black handles are you sure the valve itself turns? Sometimes the plastic splits and the handle just rotates without doing anything.
Try removing the handles and turn the spindle with a spanner.

 

[John.g]

If water comes out both valves with flexible hose disconnected then either the mains pressure is too low or the pressure gauge is stuck (give the base a judicious rap of a spanner) or (more unlikely) the top up supply is from a cold water header tank (CWST) and won't ever be higher than ~ 0.5 bar.
Have you reset the boiler water hi limit stat?, it usually hides under a plastic cover which can be unscrewed, on the boiler panel.

 

[SJB060685]

Have you confirmed water passes when you open up the filling loop valves, can you hear water flowing? You could dip the end of the hose in picture into a container and slowly open valve to see if you collect water.
Also I imagine the hot water cylinder is in an airing cupboard on the upstairs? In which case although the pressure on the guage is lower than 1 bar you probably still have enough water in the system. Its possible you have a burner fault (check to see if burner is in lockout mode) or an electrical problem within the system.

 

[ForrestB]

Hi all thank you for your advice so far. I have have checked all isolating valves on the filling loop and this was not the issue they all work ok. I have then as John G explained done a reset on the tank. I believe it’s a overheat lockout rest or something of this kind. I have then drained most of the tank and let air back into it via the air release valve on the side of the tank. I have then closed the hot water taps downstairs and refilled via the mains. And both heating and hot water now function after a reset at the oil pump. This is obviously not fixing the issue I guess I just got lucky. Would you guys just recommend I get it booked in for a service. As these must be a underlying issue. Plus I can’t get the pressure to move either and the needle on the pressure indicator does move. Making me believe it’s not faulty. Thank you all for the help so far!!

 

[John.g]

Probably best to get someone in to check out the system.

 

[SJB060685]

If you've had to press the burner reset button then you've had a burner fault. Air in system, or low pressure will not contribute to a burner fault, the burner lockout is a sign of a burner fault only