That looks like a turboMAX to me and it would be virtually impossible to get the cover off. The cover is as deep as the boiler.
The contractors who said they had serviced it must have removed all of the cupboard contents, the cupboard and the fitted shelf underneath. And then put it all back together again.
And you complain about the chap being rude - you've just wasted his time, and he has lost money. I guess the best analogy is that you are invited to a job interview, you drive there with your suit and your CV - only to be told there is no job.
In terms of who is wrong;
1. The original installer did not put it in to manufacturer instructions and has therefore not complied with the gas regulations
2. The various registered businesses who said they have serviced it but plainly have not.
The contractors who said they had serviced it must have removed all of the cupboard contents, the cupboard and the fitted shelf underneath. And then put it all back together again.
And you complain about the chap being rude - you've just wasted his time, and he has lost money. I guess the best analogy is that you are invited to a job interview, you drive there with your suit and your CV - only to be told there is no job.
In terms of who is wrong;
1. The original installer did not put it in to manufacturer instructions and has therefore not complied with the gas regulations
2. The various registered businesses who said they have serviced it but plainly have not.