Worcester Greenstar 35CDI has stopped working

[Nicholas]

With regards to this, first check that the system pressure is at one bar and if not, recharge the boiler to at least one bar (there are video of how to do this on the Worcester Bosh website, https://www.worcester-bosch.co.uk/heating-advice/boiler-pressure)

After this is done hold the reset button for 5 seconds. The boiler should then go through its ignition sequence. If going through the ignition sequence it fails and goes to lockout check that the gas supply is on to the boiler and also check that the condense discharge pipe is not frozen. To check the condenses pipe, isolate the boiler from the electrical supply. Disconnect the flexible rubber connecter at the bottom of the boiler which joins the condense outlet. And use a vacuum to see if air can be drawn through both the condense outlet and the condensate trap located in the boiler. If these are cleared, rejoin and try to fire the boiler again.

If the boiler still fails to ignite check the operation of the gas valve using a monometer on the outlet nipple to see pressure increase when the valve is energised. Also check the vacuum produced on the suction side of the fan this should be a minimum of four millibars of negative pressure.

If it is lower than this it means the heating exchanger will need to be cleaned out.

Also check that the shaft of the pump is free to rotate by opening the vet plug at the front of the pump and using a small bladed screwdriver, check it rotates easily.

[Shane Hardy]

Hello Nicholas,

Thanks for the helpful advice.

Much appreciated