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My bosch 21E (infinity style) hot water system has an intermittant fault where the flame does not appear to be able to stay on (or properly light). Once water is started to the unit I can hear the ignitor go on and the fan start (and I think I can gear the flame light too) but then almost immediately it sounds like the flame goes out and tries to reignite. It never actually lights properly though, just continues the same ignite-fan-flame out-ignite cycle. After a while (a day or so) it seems to go away. It doesn't seem related to rain but does seem more prevalent on cold days. is there anything I can do without calling a plumber? Cheers, Pete

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Moisture is getting into circuit board, usaully this sealed in a jell which keeps the board protected from any kind off dust,moisture etc which would comprimise the thinking side off the unit. a bosch engineer should be able to do a diagnostics on site.

Posted on Sep 10, 2008

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