Cooker extractor hood not fit for purpose - what's the best resolution?

itm2

We bought a Bosch extractor hood (DLN53AA70B) as part of a completely new kitchen earlier this year. It is externally vented. A few weeks ago we noticed that alot of condensation was building up on the extractor, and it was dripping back onto the pans on the hob. We contacted our kitchen supplier, and they told us that we needed to phone Bosch customer service. A Bosch engineer visited earlier this week, and noted the problem. He couldn’t find a mechanical fault with the unit or the ventilation, but could see that a lot of condensation was building up (on both the metal grill and the rotor blades) and dropping back onto the pans on the hob. He said that he would file a report and that it would probably be sent to their manufacturing division (as it looks like a design fault), but did not know what they would be able to do about it.

Basically the air flow through the extractor cools down the steel grill and rotor blades and causes the steam to condense. I looked at the reviews of this model on the Bosch website - it seems to be a common problem (I’ve added my own review):

https://www.bosch-home.co.uk/product-list/cooking-baking/cooker-hoods/canopy-cooker-hoods/DLN53AA70B?bvnotificationId=0307335f-c834-11eb-8378-02b43e775e33&bvmessageType=REVIEW_RESPONSE&bvrecipientDomain=ianmanning.com#/Tabs=section-reviews/

So it is basically not fit for purpose. 

I phoned Bosch again this morning to ask what was happening next, and they told me that I needed to speak to my retailer (i.e. the kitchen supplier/installer) - who had already told me that I needed to speak to Bosch to resolve it.

The kitchen installation commenced on January 4th, but the work has been dragging on for months due to delays in delivery of parts from Germany (we are still waiting for 2 remaining parts to arrive). The extractor hood itself was not fitted until April 21st, but all of the appliances were paid for last September (2020), so it's not clear what our rights are under the Consumer Rights Act, which quotes different entitlements depending on whether the problem is reported within 30 days, 6 months, or more than 6 months.
Does anyone know what we should expect of the retailer (or Bosch) by way of resolving this?

coffeehound

itm2 said:
I phoned Bosch again this morning to ask what was happening next, and they told me that I needed to speak to my retailer (i.e. the kitchen supplier/installer) 

Have Bosch completed the technical report?

the_lunatic_is_in_my_head

www.legislation.gov.uk/ukpga/2015/15/section/19/enacted

(14)For the purposes of subsections (3)(b) and (c) and (4), goods which do not conform to the contract at any time within the period of six months beginning with the day on which the goods were delivered to the consumer must be taken not to have conformed to it on that day.

So 6 months starting from the day the unit was delivered I believe and ending when you first contacted the retailer. Claim is with the retailer (unless Bosch offers a warranty which is a separate thing). 

www.legislation.gov.uk/ukpga/2015/15/section/10/enacted

(3)The contract is to be treated as including a term that the goods are reasonably fit for that purpose, whether or not that is a purpose for which goods of that kind are usually supplied.

If the extractor fan isn't extracting moisture but instead cooling it so it drips over the hob I can't see how it can be argued it's fit for purpose unless it's been installed incorrectly

Your OP reads as if you purchased the appliance from the same company doing the fitting but either way if you are within 6 months that's for the retailer to show rather than yourself. 

Keep_pedalling

Steam hitting metal at room temperature will condense, in this case it seems the small extractor is not up to the job in your installation. This could be for a number of reasons including being installed to high above the hob, or a long run of ducting to the external vent. 

It seems this particular extractor hood lacks the power to extract the required volume of moist air coming off your pans, so time to complain to whoever designed and supplied your kitchen.

JHW1942

You need that technical report.  Just drawing on some basic physics, the problem is almost certainly flow rate.  The cooking steam should flow fast enough that it does not have time to condense on the grille, fan blades or ducting, meaning that the water is still in steam form when it exits your house.  At this time of year, the metal and plastic parts will all be at a relatively warm ambient temperature c.20 degrees, so you shouldn't have any visible condensation if the air moves quickly enough.  That suggests to me one of the following possible causes:

Possible design faults:
- the fan isn't powerful enough 
- the apertures are too narrow or too convoluted and so are restricting airflow
- the specifications for installation, ducting, etc. aren't enough to prevent the problem from happening

Possible installation faults:
- something silly like some protective wrapping or packaging has been left in place and is restricting airflow (I know it sounds daft, but has your installer actually taken the ducting run to the outside wall, and is it free of packaging?)
- the run of ducting is too long and/or has too many bends between the inlet and outlet 
- the wrong type of ducting has been used (too narrow)

If it's a design fault, verified by the technical report, then speak to the retailer.  They'll have to repair or refund (little point in a replacement if the product design is inherently flawed).

coffeehound

Keep_pedalling said:

It seems this particular extractor hood lacks the power to extract the required volume of moist air coming off your pans, so time to complain to whoever designed and supplied your kitchen.

Yes the spec does seem to be anaemic as other Bosch hoods the same size are twice+ as powerful.  Another reviewer states it worked after the installation was corrected, so it is probably viable as long as the installation is correct and there's free movement of outdoor air into the kitchen.

zoob

Hi, could you supply the model off the hood, also is this in a new build or new extension? 
Just 1 more thing, how far from the hood to the outside wall vent ? 

JHW1942

zoob said:

Hi, could you supply the model off the hood, also is this in a new build or new extension? 
Just 1 more thing, how far from the hood to the outside wall vent ? 

It's in the OP link.  It's the cheaper one of the range, so is probably only designed for a very short run.  To get decent extraction, you need to spend 2-4x as much.  I suspect OP's installation may not meet the product's specifications and as Keep_pedalling says, that may put the fault on the people that designed OP's kitchen.

zoob

Thanks for pointing that out JHW 
Yeah that canopy hood has ok extraction for short run thru wall
Possibly underpowered but also if its a new kitchen with new well sealed windows and doors, that could be causing the problem, no hood however powerful the extraction rate is will work in a vacuum, open a door or window and see if hood extracts 

JHW1942

zoob said:

Thanks for pointing that out JHW 
Yeah that canopy hood has ok extraction for short run thru wall
Possibly underpowered but also if its a new kitchen with new well sealed windows and doors, that could be causing the problem, no hood however powerful the extraction rate is will work in a vacuum, open a door or window and see if hood extracts 

A good point.  I installed my own bathroom extractor a few years ago.  Started with one of the DIY kits with a ridiculously weak fan and concertina ducting, realised it was a waste of money so installed a decent fan with solid-walled ducting and it will pull a sheet of paper up from quite a distance, BUT, is noticeably less effective when the bathroom window is closed rather than a little ajar.  You can hear it in the fan pitch.

itm2

This is how the installation looks. The distance from the bottom of the extractor to the top of the hole venting out through the wall is about 75cm. I'm not sure why the installer vented it so high up (there was no prior vent hole in the wall before they started work). There was/is a power socket about halfway up the wall, though, so maybe he just couldn't be bothered to move it?
So the comments above suggest that responsibility for this may lie with the kitchen supplier (who designed, specified and installed the whole lot)?