Baxi 80e/105e Flue Extension? Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[sjromaine]

Hopefully I'm posting in the right place - newbie I'm afraid.

I have a Baxi 80e or 105e, can't tell which from the casing and it's about 10 years since I bought it. It's mounted in a cupboard under the stairs on what was an external wall. I just built a garage on that wall and the flue terminal is now IN the garage. Couple of questions...

1 - How necessary is it that I reposition the flue terminal? Is it safe to run temporarily? I will not be spending lengths of time in the garage and it is not used for vehicles and so has no exhaust contamination of it's own.

2 - What might happen to the boiler if I run it with the current terminal in terms of air intake? The garage has a breathable roof and a gap under the door etc and so is by no means air tight.

3 - How can I find out if the bloody thing is 80e or 105 e as the maximum flue extension is longer for the 80e?

Cheers in advance for any advice. I'm also assuming that I may not do any flue extension myself even if I do find the correct formula but must have a Gas Safe engineer do it for me. Am I correct?

[plastic_man77]

@ sjromaine

I'm sure you have a television or read newspapers, which is why I'm surprised that you don't seem to be aware of the dangers of carbon monoxide poisoning.

The flue, as you seem to acknowledge, should terminate outside, so that fumes don't accumulate inside the property and so that air for combustion can be drawn from outside. Even though your garage is not sealed, if you were to run the boiler for long periods, such as over winter when using the heating, the boiler would gradually contaminate the air being sucked in to the boiler for combustion, which would cause vitiation of the burner flame, thus causing it to produce more carbon monoxide, possibly dangerous levels, which would be forced in to your garage by the boiler fan, which would further contaminate the air in the garage, making the situation worse. If the garage was sealed, the contamination would eventually cause the boiler to choke itself, but because of the breathable roof, the boiler might keep running, with dangerously high carbon monoxide exposure levels in the garage. If your garage is connected by a door to your house, this makes it even more dangerous, but even if not, if somebody went in to the garage for whatever reason, they could be overcome by the fumes in a short period of time, possibly killing them.

If you wouldn't like to be responsible for somebody's death, then I'd advise not running the boiler until the flue terminates outside. Rules and regulations are made for a good reason. If you invited a gas engineer to your house to look at the boiler, the boiler would be classed as immediately dangerous and would need disconnecting from the gas supply until corrective work is carried out.

If you undo the front panel of the boiler and raise it about 4 inches, you will see a data label which will tell you the boiler model. Next you need to find out if you can purchase the appropriate flue extension parts to leave the flue compliant with the manufacturer's instructions/current regulations. If you can't, you will either have to pull down your garage or have another boiler installed.

The alterations to the flue will need to be carried out by a registered gas safe engineer.