Best way to block air vent?

[Dekks]

We moved into our house six months ago, which originally had pre-pay key meters, we had them switched to credit meters a few days ago, and as part of the installation the engineer did a gas safe check of all our gas appliances.

Our boiler was given an 'At risk' status due to an air vent to the outside having been installed too close to the boiler flue, which is located in a small upstairs bedroom (which is never occupied/slept in). The engineer suggested to us its more a breach of code than an immediate risk, but that we should get the vent blocked up in case because if the boiler became faulty there would be a risk of fumes coming in via the vent. He suggested we should just fill in the space in the wall with expanding foam and this will make it air tight.

Is this really the best way to go about it? We don't have an issue with blocking it up, we don't have any condensation issues and I believe the previous owner installed them all himself because the tenants they had kept drying clothes inside and causing condensation/damp problems and would never open windows.

Would using expanding foam be bit of a bodge job? If so, is there a way to properly seal the vent off myself that a somewhat novice DIY-er could do or is it just best getting a professional in? I'd rather shell out the cash and be safe, but if it is something easily done myself then I'd rather not spend any more money than I have to.

 

[freddiemercurystwin]

In the first instance I would block it with a thin plastic sheet (think ice cream tub lid or similar) and seal it up with gaffer tape. Then after the winter if you don't get any condensation issues you could block it up permanently.

 

[^woody^]

or just fit a carbon monoxide alarm in the room - which covers you for if the boiler spills into the room too.

 

[Dekks]

Already have mains powered alarm with battery backup situated next to the boiler. I ran the test cycle the other day and nearly blew my eardrums, it definitely works

I'm not particularly over concerned by the vent being close to the boiler, but it would be nice to know its up to code etc whenever someone has to check or service the gas appliances. If it was just a few centimeters further away I think it would be fine (Is 300mm still the reg min distance?).

Alternatively, if we're planning on replacing the boiler in a years time or so, could the flue exhaust be diverted so it meets the distance requirements?

 

[kazuya]

an alarm next to your boiler wont tell you if there's carbon monoxide fumes getting though the vent into your bedroom
and yes they could divert the flue

 

[Dekks]

an alarm next to your boiler wont tell you if there's carbon monoxide fumes getting though the vent into your bedroom
and yes they could divert the flue

The boiler is in the corner of the bedroom, with the vent situated a little distance away, sorry if I didn't make that clear.

(And I appreciate all the responses so far)

 

[footprints]

I would normally be very cautious about blocking vents where gas appliances are fitted, but if in this case the Gas Safe engineer has recommended it I think (assuming you are not up for re-bricking it) I would stick a sheet of stiff plastic, aluminum, formica or whatever you have that is going to be waterproof to the inside of the outer vent with silicone.

Then stuff the hole with insulation ideally that non itch stuff they make from recycled bottles but rockwool or fiberglass will be fine then put the inner vent back to cover it.
If for some reason at a later date you need to reinstate it it is easy to do.

If you have bought the house my advice would be to get the boiler moved from the bedroom, although it is legal (for a room sealed boiler only) to have it there it is not really a good idea.

Both from a safety point of view and the annoyance from the boiler noise.