Vailant EcoTec Exclsive 838

25 Feb 2004
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United Kingdom

I would appreciate any advice with questions below
Vaillant EcoTec Exclusive 838 13 rads on system

What is the most efficient burner anti cycle time with target feed of 70 degrees. The current default is 20mins.

Also would you expect the default pump target value (Auto) to be able to handle this system – it seems to take a while to heat up on this but seems better with pump at 100% but some noisy rads. Might it be better to leave on auto and increase the bypass valve value instead


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Leave all the settings as they come. There is no need to alter any values except the heat output in D0 to match the output of your radiators. If your having a problem after that then there is a fault.
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13 rads equates to approx 19Kw. Set D.0 to 19, D.1 to 7 and leave D.2 at 20. Only on a handful of jobs have I ever set this to a lesser figure. Usually to overcome incorrect pipe sizing or microbore systems. The figure of 20 relates to a 20min reignition delay at 20C flow temperature. At 70C it would be around 3-4 minutes. Which is fine.


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