If he sis this to refill the condense trap then it must be done slowly
If you have the GC number of the appliance I will show you the correct way to do it according to the Manufacturer's Instructions
GC number of our Alpha CD18R is 41 532 04
Item 7.4, do it internally!!!!!!!
Which means do not put it down the flue.....
The boiler MUST ALWAYS be serviced as per Manufacturer's Instructions and should not be attempted unless they are on site.
If you do not have a copy you can print one from the link I sent you or he must produce his own
I assume he took the burner out to clean it as explained in the MI's?
Otherwise it is not a "service"
Thank you for your reply. I have a copy of the manufacturer's service instructions. As far as I can tell, apart from putting water into the flue, the remainder of the service was carried out properly. (I assumed that all would be OK and did not stand watching him.
This is why you should not pay, they have not done it right and blown your fan themselves.
You should argue this and send them a small report about how he poured water down the flue and point them to the page mentioned in the link I sent you about how to perform this correctly.
Speaking to Gas Safe threatening to take them to the small claims court might keep them quiet, as their engineers require additional training on this appliance