Worcestr Greenslave 18/25 - have increased pressure and fires up ok but locks out after about 2 mins each time. Any clues?

My first guess would be that it sounds like a clogged oil filter, air in your fuel line, is piping overhead, or leak in a fitting or connection causing it to loose it's prime when running.

I have also seen primary controls that are faulty do this, watching the complete cycle of the run time will give you more clues as to when the control actually locks out. Does it lock out during the run cycle as the boiler reaches temp.? If so,check for oil line and suction issues as stated above.

If it locks out on start up after reaching boiler set temperature, if hitting reset right away burner doesn't start and lock out occurs with no motor engaging, check motor (Note: Some motors when HOT will not kick in when powered, but after they cool down naturally they start, motor shaft may also be bound up tight, replacement is necessary) if burner motor spins but does not fire, check for fuel flow to the nozzle, be sure oil is pumping to the nozzle, if it is, clean cad cell eye, and check transformer for spark, if all is good.. replace primary control.

Disclaimer:
Of course all this information is technical troubleshooting information and should be performed by a Licensed Technician, not knowing how to properly test for flame failure can cause injury, fire or worse! Consult a technician in your area if you are not proficient at oil burner repair!

You either have a weak spark from your ignitor which needs replacing, a bad elec connection to the ignitor, or it needs to be repositioned nearer the burner. Check connections and try repositioning it before you install a new on.

Possible flow sensor issue. Check to see if your water pressure fluctuates a lot or is fairly steady. These units are sensitive to the pressure. take care.

Hi,
There is a LED on the control board that will be flashing, telling you why it shut down....
Then look on the inside of the cover to find out what is shutting the heater down...it may be a very simple problem...
It may also be that the gas pressure is too high and it is causing the heater to lockout...
You may need to have a pressure regulator installed in the gas line ahead of the heater...they are vey sensitive and if you are ina cold area often the gas co. will increase the line pressure in cols weather to get enough supply to their customers...

heatman101

Turn on the boiler and jump out the pressure by putting a wire between the 2 electric connections only after the unit fires up than put the jumper on, if it runs ok it is the pressure switch.

First check pressure over 1 bar ok then-
1. check flow - is it adequate - a little less than the cold tap ok then -
2. does the boiler initially fire up on low hot flow but alternate as u say
If answers are 1. no but 2. yes then check for a furred up secondary heat exchanger
if 1. yes but 2. no [that is the water not the heating] goes hot / cold and if the boiler goes out when the water goes to cold then it's the diverter valve, either to replace or if it is one which has a internal diaphragm-replace that

Hello. let me help you. The water pressure is what it is in the house. In other words, the tankless water heater doesn't increase the pressure of the water, it only heats the water. There is no official minimum pressure but the minimum pressure you would be happy with in any home would be 20 pounds per square inch, PSI.

first off ensure water is getting to boiler, next, No pilot = pressure switch. On my baxi solo 40 pf pressure switch is replaced 8-10 times a year cures your problems,,,,,,,, momentarily , and have had all your other parts,but with no effect to speak of,.......sorry............ solution = [ change boiler ].sounds like gas pressure or lack of water to system or **** boiler like mine .........good luck.