Vaillant system boiler 612

[parekr]

I am considering fitting a new Vaillant system boiler 612 to replace Baxi back boiler. I live in a 2nd floor flat in 5 flat building. I was told by gas plumber that I may just have enough gas pressure to operate the 612 boiler but not models 615 & above.I have 6 double fin radiators & hot water is heated indirectly via a hot water cylinder. My questions are:-
1. Is 612 boiler adequate for my needs?
2. What is the minimum gas pressure required?
3. What is the minimum gas flow volume is required
for 612 to be operational.
Feedback from pros would be appreciated.

 

[gas4you]

Without knowing what size your rads are, it is impossible to say.

I take it that your RGI means that your existing gas pipe size will only be large enough to cope with a 612?

The 612 needs 1.3m3/hr to operate correctly. A 615 needs 1.6m3/hr.

The gas pressure should be 21mBar at the meter and 20mBar at the appliance (Perfect text book scenario)

Whatever make of boiler you choose, they will all require the same amount of gas for the same output.

I would stick with the Vaillant.