Core vent needed?? 6.9kw gas fire + Cavity Wall Insulation

[Painey]

Hi, hope I've put this in the right forum as I'm desperately in need of some advice from anybody in the know.

We've recently had Cavity Wall Insulation fitted to our detached house and they insisted on fitting a large, and very cold, core vent in the lounge due to us having a 6.9kw gas fire.

The problem is, it's made our house freezing cold! We're not even into winter yet and after paying for a warmer house, we now have a much colder one.

So I'm trying to find out if they 100% needed to fit the vent or not? Or if the vent WAS needed whether they could have fitted a baffled style vent to keep out the draft? We were told we wouldn't notice the draft but one side of the room near the vent is 10C cooler.

If it helps I'm not sure exactly what tests were carried out by them prior to installation. They said the vent was needed before doing any of that and when fitting it just checked the chimney functioned OK.

Really appreciate any help as I feel like I've been had.

Cheers - Chris

 

[kbdiy]

I believe they are correct in the assertion that ventilation is required, based on a vent that had to be installed in my mother-in-law's house for a much lower rated gas fire than yours.

Also it cannot be baffled as that prevents free air flow and thus would defeat the object of the vent. Some of the gas experts on here will probably be able to quote the precise regulations that cover this. They wouldn't have had to do any tests prior to fitting - it's just a necessary requirement, as far as I know.

 

[JohnD]

I wonder where the incoming air is going to? Is there a tremendous draught going up the chimney, or is warm air rushing upstairs and escaping through windows or into the loft? Or is there a draughty window on the far side of the room?

Does it make any difference if you close the room's door?

What sort of gas fire is it? Is it fitted in an open fireplace with a big chimney?