Replacing old boiler with like-for-like new one - possible?

[JimboMarimbo]

25 years-old Glow Worm 24cl needs replacing, but no-one will take on the job, because of difficult/impossible access to the outdoor vent pipe.
Since the boiler's original installation in the first floor flat's kitchen, a conservatory roof has been erected below, in such a position that no ladder can be positioned for the work.
I have had the heat exchanger flushed, an expansion tank fitted and the filling loop replaced, but still the hot water runs - literally - hot and cold, a very unpleasant showering experience.
It occured to me that if the 24cl is still in production, or it is possible to buy a completely reconditioned unit, it might be possible to unplug/disconnect the old one and slot into the same mounting position, a complete as-new replacement, using the same vent-to-exterior and overflow drip pipes as before.
I am aware that there will have been numerous regulations over the decades, but I am hopeful that some solution on these lines might be do-able - or if not, any suggestions from a thoughtful professional would be gratefully received.

 

[denso13]

It can be done from the inside by someone who knows what they are doing. It isn't too difficult.

 

[Hugh Jaleak]

Will need complete replacement, I think it highly unlikely you would get anything like that now. Wort case scenario, a scaffold may be needed to access the external position, but should access be needed, I would expect removal of the conservatory roof could be undertaken, with replacement after work has been completed.

 

[ianmcd]

What you are calling a vent is the flue or chimney to be precise, it can be installed from the inside, do you think we all have massive ladders when fitting a boiler in a top flat ? you will have to consider the condensate disposall however but that can be covercome using a pump if needed, your boiler is a standard efficiency and can no longer be installed so no chance of doing what you suggest

I have had the heat exchanger flushed, an expansion tank fitted and the filling loop replaced, but still the hot water runs - literally - hot and cold, a very unpleasant showering experience.

Doesnt mean that it is the boiler, and if it is it can be repaired

 

[muggles]

That boiler is long out of production, but replacing it along with the flue shouldn't be difficult. There are a couple of different techniques for replacing flues like yours without needing to go up a ladder

 

[CBW]

There could be the possibility of a vertical flue too.