Worcester Bosch Greenstar 37CDi Combi showing code U9?
My boiler is showing code U9, I know this means that the temp has risen to 99 degrees. The result when I turn the hot tap on the boiler just stops and we have no hot water. What causes this and what can I do to mend it? Do I need an engineer?

Shelley, March 2022

http://gasboilerforums.com/forum/viewtopic.php?t=642

https://www.boilercentral.com/guides/worcester-boiler-error-codes/

It might be a failed pump. Safest is to get a Gas Safe certified engineer to look at it.

I think Worcester Bosch will offer a maintenance contract. You'll probably have to buy a 6 month subscription but it might be worthwhile long term.

Rkttkmtj, March 2022