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Bosch Worcester Greenstar CDi Conventional boiler. Central heating only comes on when hot water is also on. Central heating cuts out when hot water is off.

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SOURCE: My Worcester Bosch Greenstar Combi

just had same problem.  this apprently happens if the power supply has been interrupted or you switch the power on and off.
• The boiler runs for 15 minutes at minimum heat output to fill the condensate trap, the display (K) alternates between -II-” and the boiler flow temperature. This occurs every time the mains supply has been interrupted.

Posted on Jan 07, 2009

  • 30 Answers

SOURCE: bosch greenstar 30 CDi - no central heating or hot water!

it sounds like the system was not cleaned properly when the new boiler was fitted. all new boilers need to have the pipework flushed to remove any debris scale sludge and flux from the system. this is now usually done by a power flush which is basically a big pump mounted on a big bucket and it washes the dirt out of the pipework and collects in the bucket. if this is not done the dirt will block up the small passages in the heat exchanger. i suggest the system is cleaned flush and the heat exchanger changed to help protect the boiler a filter should be fitted (for example a magna clean) if the company who installed the boiler is corgi registered then they are liable for the damages. call corgi for advice.

Posted on Mar 26, 2009

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• The boiler runs for 15 minutes at minimum heat output to fill the condensate trap, the display (K) alternates between -II-” and the boiler flow temperature. This occurs every time the mains supply has been interrupted.

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Hope this is what you wanted..

Let me know if you need any thing els.....

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