Back boiler venting and flue requirements

[Ejhoole]

Hi all,

Apologies if this has been covered elsewhere but I can't find an answer to my questions.

I have a back boiler and gas fire which h has been serviced regularly over the years by different engineers with no issues.

Last time , the guy wanted to condem it due to not being compliant with the regulations. I've tried to look this up myself but am having difficulty. I'd be massively grateful for some advice.

There are supposedly three issues, vent too small, wrong flue, boiler compartment not sealed.

Fire is Housewarmer legend, max input 6.74kw (assume gross so 6.12 net).

Boiler is housewarmer 55 max input 21.5kw (assume gross so 19.6 net)

Total is 25.72. Vent area = 25.72x5= 128cm2.

My vent hole is 12x20 = 240cm2 but has a grille on outside and inside. Outside has very large holes with very thin bars so I am sure it will be at over the 128 needed.

Cover on the inside is too small. I looked it up and it's 68cm2 due to the grille pattern.

So can I just replace the internal grille to allow more airflow? The guy seemed to think the actual hole size was too small not just the grille. Have I done the calculations correctly?

Secondly he said that I need a double sleeved flue so air can pass up and down. I thought this was for combi boilers. It just has an aluminium flue going up the chimney which as far as I can tell is OK.

Thirdly, he said that the boiler compartment should be sealed and to be fair you can see the boiler through a gap on the other side of the wall. There is a cupboard there and if you open the door you can see the boiler compartment. There is a gap where the outer compartment houses the flue, so not a hole in the flue itself. As I can see the boiler through the gap, I agree with him on that one but I don't know why is wasn't picked up before.

My plan is to cut some ply to size and seal is all off with no more nails or similar. Would this acceptable?

Thanks for any help with this. I am scared to get someone in to take a look in case they condem it and I can't deal with that right now.

Cheers Edward

 

[Last Plumber]

The ventilation free area is what needs to be measured.

The flue, I don't follow your explanation. Normally they are copex (corrugated stainless liner) off the boiler top up into a chimney. Some have flue pipe off them and go up through the building. They are normally twin wall flue unless they're asbestos cement or similar.

Compartment:
I have an image in mind but it could be vastly different to what you described. Can you post images of this set up?

If others have serviced it before and said nothing, I would think these are minor issues that can be rectified. Post photo's and we can see it.

 

[Ejhoole]

The ventilation free area is what needs to be measured.

The flue, I don't follow your explanation. Normally they are copex (corrugated stainless liner) off the boiler top up into a chimney. Some have flue pipe off them and go up through the building. They are normally twin wall flue unless they're asbestos cement or similar.

Compartment:
I have an image in mind but it could be vastly different to what you described. Can you post images of this set up?

If others have serviced it before and said nothing, I would think these are minor issues that can be rectified. Post photo's and we can see it.

Thanks for your reply and sorry for the slow response. Was waiting on any more replies then had a busy few days,

Yes it's a corregated pipe from the boiler through the chimney.

With regards to the compartment. I will try and get some photos. Basically the boiler is inside a large chimney with the gas fire facing into the living room, on the other side of the chimney is a cupboard and if you open it there is a metal box housing the boiler with a round section for the flue. Where the round section joins the box is a gap and you can see the boiler through the gap.

Thanks

 

[Last Plumber]

Thanks for your reply and sorry for the slow response. Was waiting on any more replies then had a busy few days,

Yes it's a corregated pipe from the boiler through the chimney.

With regards to the compartment. I will try and get some photos. Basically the boiler is inside a large chimney with the gas fire facing into the living room, on the other side of the chimney is a cupboard and if you open it there is a metal box housing the boiler with a round section for the flue. Where the round section joins the box is a gap and you can see the boiler through the gap.

Thanks

It sounds like that needs to be sealed from the cupboard side but yes, post photo's if you can.