I had same initial problem, same resulting symptoms, removed restrictor plate and problem solved!! Mine however was a horizontal side flue (and not rear flue) so according to the manual was not required in the first place.
Thanks to a great posting and contributors
I checked the tubes and trimmed one that had a slight kink and retried boiler. The boiler ran a little longer before cutting out and then in again so I believe this contributed to the issue but was not the primary cause.
I took the decision to remove the fan restrictor as this should never have...
"What you are doing is dangerous" Guys appreciate your comments but I didnot run the Boiler with the Combustion Box Door Open for any Duration, only as a test. Replacing the Fan unit was a simple enough job for an Engineer with good mechanical / electrical knowledge & more so common sense ...
I have just today received & replaced the Fan Unit on my Baxi Solo 3 PFL 60 Boiler after the original one started to make a terrible racket & final stopped Running on Saturday (right before the coldest day of the year !!) :( .
The Boiler fired up first time, new fan ran sweetly but now the...