Ventilation to Combi Boilers

[AndrewSchofield]

We have a Worcester Bosch Combi-Boiler which was fitted by British Gas about 4 years ago. It is currently located in a bedroom but we are about to convert our loft and this bedroom will become the landing/stairs to the loft. As this will need to be a fire protected staircase to comply with BR i've been told i've got to build a cupboard around the boiler which will provide 1/2hr fire resistance.

This isn't a problem physically but i need to know how much ventillation (if any??) i need to provide to the boiler as obviously vents in the cupboard will undermine the 1/2hr status of the cupboard. Also, do i need to leave a minimum gap around the boiler?

Is there any problem with putting a vent through the wall so that the boiler gets air from the adjacent bathroom?

Any advice on this matter would be gratefully appreciated.

 

[JohnD]

you could ventilate the cupboard to the outside by core-drilling through the wall. Then the integrity of your enclosure will be unaffected. It will need to be well away from the flue and preferably below.

 

[AndrewSchofield]

Thanks John. Thats what i thought might be suggested but the house has 600mm solid limestone walls so didn't want to do that if there was another way!! If thats the best (and safest) way though, then so be it - nice little job for my father-in-law that one!!! He likes to be helpful!!

Having thought about it a bit more i already know the minimum clearance needed around the boiler because i was going to build a cupboard around it when it was first installed and checked the owners manual which details this so will have to dig it out again - was just the ventialation issue that was concerning me.

Once again - thanks for the advice!

 

[Agile]

Most modern boilers dont need any ventilation but as you have not bothered to say your model we cannot advise you on that.

The Manual will specify the requirements!

Tony

 

[AndrewSchofield]

Tony,

Apologies for not specifying the boiler Model - I am new to online forums and this one in particular. Also know very little about boilers so wasn't aware that ventialation requirements would differ from one boiler to the next. At work at the moment and don't know the boiler model off hand so will check to night and post it in the morning.

Will also check the manual.

Thank you.

 

[kirkgas]

asking on here will get you a repy, but if you have the MI's that is all you need, i do remember some of the wocester boilers require specific ventilation depending on the clearances so be careful as fitting the new cupboard wall too close to the boiler might reqire you to fit a vent, i wouldn't vent to outside as it will reduce cupboard temp too low and you could have freezing prob in winter, you can get intumescent (i bet that spelling is wrong) fireproof vents that actualy close over if there is a fire, but they are very expensive

 

[petit_pablo]

I would imagine its a WB cdi model. It shouldnt need compartments vents but double check manufacturers instructions.

 

[AndrewSchofield]

Thank you all for your help. I haven't checked the owners manual yet as i was busy last night but will root it out and have a look.

For clarification it is a Worcester Bosch 28CDi boiler.

Kirkgas, thanks for the thoughts on the outside vent - we live in the Derbyshire hills - one of the coldest places in England so think you might be right about avoiding that option!! The wind also blows towards that wall of the house and so would definately be cold in there!!!

 

[AndrewSchofield]

I have now found the literature for my 28CDi boiler and it states that no ventilation is required for cooling air to the cupboard providing i leave clearances of 70mm to either side, 30mm above the flue, 250mm below the boiler and 250mm in front of the boiler. If these clearances aren't acheived then 315sq.cm free air space must be provided above AND below the boiler. I can't find a vent that provides more than about 80sq.cm free air space (9inchx6inch vent) so i'll need four of these above and four below the boiler which seems a little excessive in light of the fact that i can provide the necessary clearances to all but the front where only 50mm clearance will be acheived. Does anyone know if it is possible to either reduce the area of free air space provided given that only the front clearance isn't acheived or maybe increase the clearances at the sides, top and bottom to compensate for the front clearance and provide no ventilation.

I have tried contacting Worcester Bosch directly regarding this and so far they have failed to reply.

 

[petit_pablo]

The clearances stated are for servicing access as well as ventilation.
I would stick to what the minimum dimensions are.

 

[AndrewSchofield]

The servicing clearances are stated seperately in the literature and are much less than the clearances required for cooling air - eg the boiler only requires 10mm clearance to each side for servicing requirements but needs min 70mm for cooling air. In any case the 50mm clearance at the front will be to the cupboard door so when the cupboard is open there will be plenty of room for servicing needs.

 

[bengasman]

Where exactly does it say in the building regs that a boiler needs to be in a fire proof compartment????
Part b is rather extensive so I did not read the lot, but a quick glance showed no such requirement, and I have never heard anything like it for a roomsealed unit.
Your stairs need to meet certain requirements though.

 

[Bamber gaspipe]

We have a Worcester Bosch Combi-Boiler which was fitted by British Gas about 4 years ago. It is currently located in a bedroom but we are about to convert our loft and this bedroom will become the landing/stairs to the loft. As this will need to be a fire protected staircase to comply with BR i've been told i've got to build a cupboard around the boiler which will provide 1/2hr fire resistance.

This isn't a problem physically but i need to know how much ventillation (if any??) i need to provide to the boiler as obviously vents in the cupboard will undermine the 1/2hr status of the cupboard. Also, do i need to leave a minimum gap around the boiler?

Is there any problem with putting a vent through the wall so that the boiler gets air from the adjacent bathroom?

Any advice on this matter would be gratefully appreciated.

Consult manufacturers instructions, then build a cupboard around your boiler. Simple.

 

[bengasman]

IF you have to build one.

 

[namsag]

Bengas once you go above2 floors and things such aswhen boilers and meters are under stair case majority of rules change. itsorgi bookAnd BS