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Brian, Plumber
Category: UK Plumbing
Satisfied Customers: 848
Experience:  16 yrs. experience as plumber, including full bathroom and kitchen installations.
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I have replaced my diverter valve on my Worcester Bosch

Customer Question

Hi I have replaced my diverter valve on my Worcester Bosch Heatslave 15/19. The fault before was that it would start with the big red button but lock out after a while. I could not switch off the radiators. When I took the valve out it was seized so I am happy that the original fault was fixed. But now both red lights are on the front. If I press the big red button I get buzzing and no boiler starting noise. Then it goes from one to two red lights on the front. I have bought the pressure back up and bled the three valves on top. Any help would be great Barry.
Submitted: 1 month ago.
Category: UK Plumbing
Expert:  Brian replied 1 month ago.

Hi Barry if you just get a buzzing it will be a burner fault.

one of three things normally.


Oil Pump seized

Burner Motor seized

if you have a tester that can read farads you can check the capacitor it should be 4 I believe but its written on the side anyway.

if thats testing ok, you need to pull off the oil pump and check the spindle is turning you can also check the motor spindle from there. my guess is one of them will be faulty.