Unusual Ventilation Requirements for Hotpoint Gas Hob GF640

[EdSet100]

Hi Guys,

A gas installer came to fit my new Hotpoint gas hob GF640 today. He read the installation guide and informed me that he couldn't comply with the requirements unless I fitted either a vertically vented hood (ie burnt gas goes straight up a flue to the roof) or a fan assisted horizontal extractor vent (via a hood) through the adjacent wall, which is automatically switched on whenever the hob is operated. This is in addition to having an unrestricted inlet vent of 100cm2 either in the kitchen or the adjacent room.

We were both surprised at the need for the automatic control of the fan assisted vent. His view is that this is required for commercial appliances only. Anyway, as I couldn't meet the manufacturer's requirement, the installer did not connect the hob.

I have no issues with his decision. I wouldn't expect anyone to ignore the manufacturer's requirements, but are they over the top in this case?

 

[superdupergasman]

usually ventilation is only required if the room is less than 10 meters cubed and has no openable window???

Phone manf to double check what they have said in the instructions

 

[EdSet100]

The instructions make no mention of the room size, except that it must have an airflow of 2m3/hr per kW of power. According to the specs sheet, the hob can produce 8.5kW, so it needs 17m3 per hour. By most standards, the kitchen is very big: at least 55m3. I don't think I have a problem. Anyway, the installer phoned the Hotpoint techies and they said to follow the instructions, which he couldn't, so he went home.

 

[superdupergasman]

I hunted down the instructions and I think there has been some things lost in translation or something because I have never seen extraction volumes etc mentioned..... I would go by the BS 5440 part 2 which in your case would be fine if you have a large kitchen and an openable window also providing your clearances are ok to combustables.

I would also be asking hotpoint how on earth does there hob switch on a cooker hood??? does it have a switched live out or something?? that is a silly very unclear set of instructions they have issued!


GOOD LUCK!

 

[ratonnastick]

check your installation instructions carefully, someone cant be interpreting them correctly it is very unlikely a hob of 8kw requires this sort of ventilation, if the hob was installed and then the instuctions removed or lost then you would use bs5440 which would say it was ok.

 

[superdupergasman]

check your installation instructions carefully, someone cant be interpreting them correctly it is very unlikely a hob of 8kw requires this sort of ventilation, if the hob was installed and then the instuctions removed or lost then you would use bs5440 which would say it was ok.

http://imagebank.indesitcompany.co..../Hotpoint/Cooking/GF640_GF641_19503640402.pdf

have a look for yourself....they are really bad!!!

 

[clf-gas]

I would also be asking hotpoint how on earth does there hob switch on a cooker hood??? does it have a switched live out or something?? that is a silly very unclear set of instructions they have issued!

Its called an interlock system, found in commercial kitchens. Extract is switched on, PS proves fan is working live feed is given to solenid valve in gas supply pipe, fan fails gas shuts down. HSE CAIS 23. does not apply to domestic kitchens.

GF640 is a four burnner hob, interlock wont be required for this.

Give us the link to the MIs Zimmer

 

[superdupergasman]

there is no mention of wiring up the interlock from this hob...there is a big mistake in the instructions.


http://imagebank.indesitcompany.co..../Hotpoint/Cooking/GF640_GF641_19503640402.pdf

 

[ratonnastick]

take that all back the instructions for this appliance are crazy can only think that someone got very paranoid about ventilation for this or maybe a misprint.






Positioning the Hob
Important: this unit may be installed and used only in
permanently ventilated rooms in accordance with British
Standard Codes Of Practice: B.S. 6172 / B.S. 5440, Par. 2 and
B.S. 6891 Current Editions. The following requirements must be
observed:
a) The room must be fitted with a ventilation system which vents
smoke and gases from combustion to the outside. This must
be done by means of a hood or electric ventilator that turns
on automatically each time the hob is operated.
In a chimney stack or branched flue. Directly to the Outside
(exclusively for cooking appliances)
b) The room must have an air flow to allow for proper combustion.
This must be 2 m3³/h per kW of installed power. The airflow can
be created using an enclosed vent with an inner cross section
of at least 100 cm² which must not be able to be blocked. I the
appliance does not have a flame failure device, the vent must
have an internal cross section of 200 cm3³ (Fig. A). Alternatively
the room in which the hob is situated can be vented indirectly
through ventilation ducts as specified above, as long as the
adjacent room is not a shared area, a bedroom or present any
risk of fire (Fig. B).

 

[ChrisR]

Wrong advice to give, the manufacturer's instructions have to be followed.

This is not a commercial kitchen appliance, which would be altogether more stringent on ventilation.
Domestic hob installation requirements are often more onerous than the BS minima.
Unless you can get it in writing that the instructions are wrong, or need not be followed, don't get it fitted unless you can comply.
Congratulations to the unnamed gasman.
I am as perplexed as he is - there doesn't appear to be an interlock for the ventilator, fitted to the hob, so it's uninstallable! I have emailed Hotpoint (Indesit) for an answer, but I'm not holding my breath!

The instructions are
here:

 

[superdupergasman]

Wrong advice to give, the manufacturer's instructions have to be followed]

there is no way for a hood with interlock to work on this applaince though Chris, as I said earlier would give Hotpoint a call and try to get a techie on the line. safest bet!

 

[clf-gas]

GF640 is a four burnner hob, interlock wont be required for this.

Well i take that back, this is a first for me, will be sending an e-mail to Hotpoint tomorrow.

Can only think of the way i do for com kitchens for extract and ventilation to prove before hob can come on.

 

[ChrisR]

there is no way for a hood with interlock to work on this applaince though Chris

Oh I agree - but it doesn't mean you can go ahead and install the stupid thing!

Anyone seen a DOMESTIC extractor with a fan proving switch? That would have to operate a gas shut-off valve of course. Barking, in a domestic kitchen!

 

[EdSet100]

there is no way for a hood with interlock to work on this applaince though Chris, as I said earlier would give Hotpoint a call and try to get a techie on the line. safest bet!

Well, thats what we did and the techies said to follow the instructions. I'm pleased that all of you guys have answered quickly and all agree with me and my installer that the instructions, as everyone has seen, are ridiculous.

I will be contacting Hotpoint, again, tomorrow. The installer insists, and I don't blame him, that he needs to have something in writing from Hotpoint before he fits their hob without complying with their instructions book.

 

[ratonnastick]

It seems that all the hotpoint gas hobs now have this ventilation requirement in there instructions.
either they are very dangerous gas hobs or hotpoint has gone mad and dont want to sell domestic gas hobs.