Why is this vent under boiler considered wrong?

[diy_fun_uk]

I have an old IdealMexico boiler running in my hall cupboard. Immediately in front of it (but still inside the cupbaord), there's a vent on the ground that goes to the crawl space under the house that in turn has air bricks to the outside. Above the cupboard door there's a vent on the wall allowing air between the cupboard and hall. There's also another vent lower down on the wall, again allowing air between the cupboard and hall.

One time when the boiler was getting serviced, the engineer told me the vents should be removed and blocked up as 'they don't do it that way anymore.'

Is the config of vents I've described above now considered a safety risk and if yes why? I'm assuming it has something to do with changing regs over the years? (the boiler would have been installed in the mid 80s.)

I quite like the idea of the vent in the ground that leads to the drafty crawl space as, to me, if there was a leak emanating from the boiler, there would be decent air circulation to deal with the escaping gas, no?

 

[denso13]

Which specific boiler is it?

 

[bernardgreen]

One time when the boiler was getting serviced, the engineer told me the vents should be removed and blocked up as 'they don't do it that way anymore.

Some Ideal Mexico boilers are natural draught, open flue gas boilers and as such require vents to provide air to the boiler.

The manufactures manual states :-

AIR SUPPLY
Detailed recommendations for air supply are given in BS.5440:2. The following notes are for general guidance: 1. The room or internal space in which the boiler is installed MUST have, or be provided with, a permanent air vent. This vent MUST be either direct to outside air or to an adjacent room or internal space which must itself have, or be provided with, a permanent air vent at least the same size direct to outside air.

https://www.freeboilermanuals.com/assets/pdf/ideal/151909-3.pdf

 

[gas112]

its called crossed ventilation . is your boiler room sealed ie flued straight out the back
be unusual to be open vent under stairs .
Vents have nothing to do with helping clear possible gas leakage
they are there for combustion air and cooling in respect of open flued boiler
and cooling regard room sealed

 

[Madrab]

We need to know the specific model of Ideal Mexico you have - the Gas Council (GS xx.xxx.xx) number would be good.

Some of them require specific sizes of air vents and take the combustion air from the same or adjacent space of the boiler but as suggested it would be unusual to have an open flued model under the stairs. Even if it is room sealed, it will probably still need specific sized vents top and bottom of the door, for cooling.

 

[diy_fun_uk]

Thanks all. It looks like a Slimline RS55 although can't say 100%. The flue goes directly to ceiling then vented out of the roof.

Yeah I get the fact the vents aren't there in case of leaks, however I quite like them being there in case there was a leak, specifically the one on the floor that leads to the airy crawl space.

 

[Madrab]

If you post a pic of the boiler and the front controls and the visible flue if possible.

 

[diy_fun_uk]

If you post a pic of the boiler and the front controls and the visible flue if possible.

I'm not going to take the panel off cause knowing my luck the boiler will shut down! Anyways, here's some pics. Ignore the tape around the flue entry into loft. I did that years back to stop wasps.

Note, I'm not querying whether the flue etc is installed correctly. This has all been checked a few times as part of previous services. I was just wondering if the historic vent setup is now considered a no no. Cheers.

 

[gas112]

Thats a mexico cf
rs donates room sealed .
Your boiler is classed at Risk because of the ventilation configuration and they should advise you not to use it and turn it off with your permission .
Under stairs i hope you have fire proof sheeting lining stair case and door

 

[diy_fun_uk]

Thats a mexico cf
rs donates room sealed .
Your boiler is classed at Risk because of the ventilation configuration and they should advise you not to use it and turn it off with your permission .
Under stairs i hope you have fire proof sheeting lining stair case and door

It's not under stairs, it's a floor to ceiling cupboard.

So, in terms of all the existing vents (one in the floor, two in the wall that vent to/from the hall) which of them should now be blocked off?

 

[gas112]

It's not under stairs, it's a floor to ceiling cupboard.

So, in terms of all the existing vents (one in the floor, two in the wall that vent to/from the hall) which of them should now be blocked off?

close the floor vent ,
to make it legal vent sizes on page 3 then a vent in your hall to outside

Plumbase Manuals

 

[diy_fun_uk]

close the floor vent ,
to make it legal vent sizes on page 3 then a vent in your hall to outside

Plumbase Manuals

Cheers. One final question on this. What is it about the current vent setup that creates the risk?

 

[gas112]

Cheers. One final question on this. What is it about the current vent setup that creates the risk?

because the air comes from different pressure zones it can effect flame picture and how the flue pulls

 

[Madrab]

You also need to know which model of CF it is, that determines the required vent size