What is the reason for pump in the gas-fired boiler does not transfer oil?

Question details (performance):

A pump in a gas boiler does not transfer oil.

Answer: Fault reason:

(1) Pump failure.

(2) Oil pressure and power are reduced.

(3) The oil inlet valve is not sealed.

(4) The inlet pipe is not sealed.

(5) The interceptor valve is closed.

(6) The filter is contaminated.

(7) The filter is not sealed.

(8) The tubing is not sealed.

(9) Pump suck air inlet.

(10) The vacuum degree in oil tube is too high.

Troubleshooting:

(1) Replace with new pump.

(2) Remove the inlet valve and clean or replace it.

(3) Seal the inlet pipe.

(4) Open.

(5) Cleaning.

(6) Replace the sealing ring.

(7) Tighten and exhaust.

(8) Clean the filter and valve.