Hmm, the sheets I have seen contain no information about what the ventilation requirements are for the room, they just say it's inadequate but make no recommendations as to what it should be. The second engineer who visited just checked the existing vent couldn't be blocked by falling debris in the cavity wall and pronounced it all good. The first BG bloke (refusing to call them engineers now) mumbled something about
10mil too small or something and then left two contradictory sheets but appears to have done some kind of combustion testing and checked the draw of the flue using a smoke cartridge.
as i say, it's hard to give a 'verdict' over a news group but, if he says the air vent is too small then it could well be that the appliance is not getting the air it requires to burn safely and/or efficiently. his actions depend on the circumstances. he should at least advise you that the vent is sub standard and requires upgrading although it may me 'legally' acceptable at present.
we always try to inform customers in plain english, after all most customers like yourself, don't know the 'ins and outs' of gas safety/requirements. (which is what keeps us in jobs)you would need to supply the room volume, is there an openable window, is there an openable door, appliance type( can be found round where you take off the cover to light it on most decorative fires) the appliance heat input (same place as type, that plate incidently is called a data badge)does the room connect with any other rooms with fires/open flue boilers that could effect the appliance. it is a mine field but if ya wanna know the that is how it is.
i have spent loads on training just to get to a stage where i can obtain a job working with gas, i think today i have just taken, and passed my final exam, the 18th not including 1 full day practical exam that i passed and the three onsite visits still to come. then there is the porfolio of around 25 to 50 completed actual jobs all wrote up in the way they like it. then i will have an interview with corgi and onsite inspections from them. then and only then can i tell you your vent is too f****ing small with a flue analyser! lol.
sorry for the rant but it is annoying when fitters/engineers just come round and say thats not right!
The chapter and verse are in BS 5400-2 whic you can find from links below.
I don't know if you were around to follow the thread about the conventional flue which got condemned at elderly woman's residence.
It caused me to make BS 5440 available online so we can all be better informed. You are right there are a lot aspect to be considered when deciding if the flue/vent arrangements are to standard or not.
On Sat, 19 Aug 2006 21:57:57 +0100 someone who may be Ed Sirett wrote this:-
Most useful it is too.
The gas board's latest wheeze is interesting. A colleague was told that the ventilation of his not room-sealed boiler is not up to current standards, something he already knew but it still works properly with no spillage. It has been the same for many years. However, their wheeze this time is to state that the current regulations will be applied retrospectively to all existing installations from next year, so would my colleague like to buy a new boiler and have them fit it?
Does anyone know if it is intended to apply regulations on air vents retrospectively to existing installations?
This is my take: If you were to apply all the rules as laid down in the standards to the letter then _most_ homes would fail in some way.
By far and away gas pipes would be under sized to achieved the required
1mb max pressure drop. Clearances to combustible surfaces would fail many a cooker (28mm side clearance required -on each side!), unless otherwise stated.
Ventilation not just for combustion put also for cooling room sealed appliances.
In practice small infringements are overlooked if all is working well.
With the advent of the CCC etc. Big organisations are going to have to make sure they comply with the letter of the law.
Following two articles in a national newspaper the industry and in particular the HSE are concerned that users of gas appliances may now be confused about the latest ventilation requirements outlined in the fourth edition of the industry Unsafe Situations Procedure, and that installers would perhaps feel reluctant to mention the changes to those customers who would not be affected until 2008. To help explain the situation the we have published the article below and to reinforce the importance of correct ventilation the HSE have a placed a similar article on their website which you as an Installer can refer customers to.
formatting link
August 2005 the fourth edition of the Gas Industry Unsafe Situations Procedure came into being. This superseded the third edition released in September 2001. As you will know, this procedure is referred to within the HSC Approved Core of Practice and Guidance on the Gas Safety (Installation and Use) Regulations 1998.
One of the major changes brought about by the Fourth edition is in the classification of undersized ventilation for open-flued appliances and therefore how any resulting sub-standard ventilation should be dealt with by the CORGI Registered Installer. The ventilation requirement itself has not changed.
It must be recognised that inadequate ventilation can be a contributory factor in unburned gas incidents and of the deaths caused from carbon monoxide poisoning each year (around 30), 80% of these involve open-flue appliances. It must also be accepted that gas users will generally treat advice that their ventilation provision is 'Not to Current Standards' as a low risk, with the majority doing very little to improve the ventilation provision in their homes.
An industry panel including CORGI and the HSE together with a number of CORGI Registered Installers were involved in risk assessing installations with undersized air vents to determine how the air vents should be brought up to the required level without creating unnecessary inconvenience or risk to gas users. It was acknowledged that hundreds of thousands of installations could be affected and whilst this was a small proportion of the total gas installations (some 24 million) the potential risks in relation to under-sized ventilation are such that this required proper action.
In recognition of the difficulties of immediately moving to full compliance on existing installations, a step change was introduced to manage the situation over a period of time ensuring that after June 2008, all ventilation provision will comply with the required standard, tackling those with the greatest deviance from the standard first. This change was published in the fourth edition of the Gas Industry Unsafe Situations Procedure.
To achieve this step change, existing open-flued appliances installed in rooms where the ventilation is 39% or less, or in compartments where the ventilation is 90% or less of that recommended by the appliance manufacturer's installation instructions or appropriate industry standard would be classified as 'At Risk' (AR) and with the customers permission should be turned off .with immediate effect (i.e.. from the fourth edition coming into effect in August
2005). Where the ventilation requirement is between 40% to 89% of the requirement recommended by the appliance manufacturer's installation instructions or the appropriate industry standard and the appliance is operating safely, it can be classified as NCS and left operating. The gas user should be advised in writing that this is a temporary situation that must be brought up to current industry standards before 1st June 2008.
Installations providing between 90 and 100% of the ventilation requirement should be classified as satisfactory due to the difficulties in measuring the small apertures normally found on a ventilator grille.
Therefore, CORGI registered Installers who encounter undersized ventilation should treat the installations in the following manner:
Open-flued appliance with 39% or less of the ventilation requirement - At Risk with immediate effect and the appliance should be turned off..
Open-flued appliance installed in a compartment with less than 90% of the ventilation requirement - At Risk with immediate effect and the appliance should be turned off.
Open-flued appliance with ventilation between 40% and 89 % of the requirement - NCS until 1st June 2008. The gas user must be informed that this situation will become At Risk on 1st June 2008. This affords the gas user the maximum possible opportunity to improve the ventilation before having the inconvenience of the appliance being turned off.
Following 1st June 2008, all installations must comply with the current standards for ventilation provision and if they do not then the CORGI registered Installers MUST inform the gas user that the appliance should be turned off until the ventilation provision can be upgraded.
Whilst there is a two-year timeframe, gas appliances do need air for good combustion and gas users should be advised that any ventilation upgrades that are suggested by their gas Installer should be completed sooner rather than later.
As previously mentioned the fourth edition of the Gas Industry Unsafe Situations Procedure was published following a thorough revision by an industry group that included HSE and CORGI and included consultation with the major stakeholders within the industry. It was particularly important that the group included the HSE and they together with the other members of the group approved the procedure prior to publication and continue to support the procedure including the recommendations on improving undersized ventilation provision. Any non-compliance with the provisions of the Gas Industry Unsafe Situations Procedure by any CORGI Registered Installer will be taken very seriously by the HSE.
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