what is wrong vaillant 242E,282E?

take off front cover to reveal burner ass`y. Bottom l/hand side is ntc sensor, follow wire back to where it attatches to dhw sensor (black one) and disconnect it but dont let it touch boiler. replace front cover and try htg , if it works then thats ur fault. these can be swapped without draining boiler but dont run boiler without the sensor being connected as what i`m telling u to do is only 4 test purposes.

paul
October 2007

either boiler blocked on htg pipework in boiler or flow and return sensors faulty

paul martin
October 2007