Observation:
INFORMATION
If the boiler is displaying this fault then it has detected that the pressure has dropped significantly over a short period of time and the intelligent filling loop is set up / activated.
If you have been working on the system e.g. bleeding radiators or you have already fixed a leak then it is ok to leave the boiler showing this fault, it will still operate correctly and fault will disappear on its own.
If you are attending a visit to an appliance showing this code then unless the customer has done something that could have caused a pressure drop then there is almost certainly a leak or other reason for pressure loss that will need to be investigated.
Check for leaks on the boiler / system.
Confirm correct expansion vessel and check PRV for signs of leaks.
Check drain point is not leaking, especially if it has an adaptor that connects it directly to the condensate.
If all seems satisfactory but boiler is still losing pressure then other possible causes:
Primary heat exchanger leaking internally into condensate.
To confirm, remove condensate trap and check for dripping from heat exchanger over a period of time.
Leaks on pipework under floors / concrete.
Check for signs of damp / leaks where the pipework runs, for concrete try to see if it has been wrapped / sleeved.
To prove you would have to isolate the flow and return valves under appliance and leave for a period of time which will
not always be appropriate depending on time of year / customer.
Excess air in boiler / system - especially if boiler is placed at highest point on the system
Check water quality & correct levels of inhibitor.
If the boiler is displaying this fault then it has detected that the pressure has dropped significantly over a short period of time and the intelligent filling loop is set up / activated.
If you have been working on the system e.g. bleeding radiators or you have already fixed a leak then it is ok to leave the boiler showing this fault, it will still operate correctly and fault will disappear on its own.
If you are attending a visit to an appliance showing this code then unless the customer has done something that could have caused a pressure drop then there is almost certainly a leak or other reason for pressure loss that will need to be investigated.
If all seems satisfactory but boiler is still losing pressure then other possible causes:
To confirm, remove condensate trap and check for dripping from heat exchanger over a period of time.
Check for signs of damp / leaks where the pipework runs, for concrete try to see if it has been wrapped / sleeved.
To prove you would have to isolate the flow and return valves under appliance and leave for a period of time which will
not always be appropriate depending on time of year / customer.
Check water quality & correct levels of inhibitor.
