Worcester Heatslave 20-25/ Lockout

[paulweber]

Hi All

Have Worcester Heatslave 20-25 (15 years old). Made the cardinal sin of running out of heating oil, filled the tank however boiler would not re start (locked out), called the engineer out who diagnosed the pump had seized, replaced the part and was ok for 4-5 hours then locked out, replaced with another pump and likewise locked out agin after 4-5 hours. Suspect the pump Is not the fault.

In addition to above have now replaced pump and tank filters and checked oil for water for contamination. Appreciate any ideas from anyone regarding how we can fix.

Cheers

Kuche

 

[oilhead]

Groundhog Day?????
This was posted last week. If the system has been cleaned out and bled, then the only other suggestion is check the non return valve behind the nozzle for contamination. Maybe change the nozzle, otherwise, try another engineer if you cannot trust the one you have.

 

[paulweber]

Yes, groundhog 3 weeks
Still the same problem, will try the non return valve changed the nozzle and filters, some seriously head scratching going on, engineer thinks of contaminated oil, is there an easy way to check this?

Kuche

 

[dcawkwell]

Steel or plastic tank?

I suspect something blocking the oil line from the tank to house.

Push some compressed air down it.

If after 4-5 hours and it locks out I you bleed the oil line does the boiler
fire?

 

[paulweber]

Plastic tank,

Will try the compressed air see if that works

No pump seizes, does not fire

Kuche

 

[dcawkwell]

Plastic tank,

Will try the compressed air see if that works

No pump seizes, does not fire

Kuche

If the pump has seized riello pumps usually fail quickly if run out of oil
But you can usually hear the pump if it is struggling for fuel.

I would disconnect the oil line from the burner and allow a few gallons to run through the line into a can that should show if there is a problem with the oil
delivery and the quality of the oil.

 

[oilhead]

A Heatslave will not have a Riello burner, but any pump will seize if run dry.
Has your engineer tested for vacuum? Another useful test is to use a vacuum pump on the fuel line to pull oil through at a fast rate.
Is the tank higher than the burner? If so, by how much?
When a pressure gauge is placed on the pump, is the supply steady or does it fluctuate?