Gas hob instillation

[tridantri]

I am in the process of renovating my kitchen. At the moment I have a free standing gas cooker connected to the gas supply via a flexible cable with bayonet fitting. I am getting a gas safe engineer to fit the new hob but have a couple of questions.

Firstly, I believe it is within regulations for me to be able to disconnect my current cooker. Is this correct?

There is no isolation valve near the cooker (only the main one on the outside of the house) but from my research the bayonet valve should self seal. Is it safe to disconnect the cooker and then wait a day (maybe two) whilst I fit the units and worktop before the gas engineer can fit the new hob?

Should there be an isolation valve for the cooker/will the gas engineer have to fit one?

Finally, I understand that a hob has to be hard plumbed, rather than using a flexi pipe. Just interested to know why this is?


Sorry, quite a few questions there but I like to understand exactly what is going on. Just to be clear, I am getting a gas safe engineer to carry out all of the work (apart from disconnecting the cooker if it is safe to do so).

 

[Steelmasons]

Bayonet self sealing fittings are considered an acceptable means of termination , HOWEVER if gas appliance is permanently removed then bayonet should be replaced using a conventional termination fitting (HSE).

 

[Gasguru]

Yes you can disconnect the hose yourself but you also check the wall fitting has sealed. Although not approved as a leak detector a weak soap solution applied to the inside of the fitting would be sensible...check for bubbles.

The hob installer will remove the bayonet fitting, install an isolating valve and connect up the hob in copper pipe. Make their life easy by ensuring the worktop cutout is the correct size and clearances are complied with. Also ensure the ventilation is correct....there's some ridiculous hobs being sold with almost commercial kitchen ventilation requirements. Hopefully the gas pipework is of sufficient size. Remember in flats etc you must have FFDs on the burners...a sensible feature regardless.

There is no reason in principle that a hob can't be connected via a hose (and you will find some hob manufacturers stating hose fitment is acceptable) BUT you must comply with the hose manufacturers requirements. The hose MUST hang in a U shape to avoid undue strain and not be located where it is subject to excessive heat. This means in practice hoses can't be used since most hobs are installed over ovens or drawer/cupboard units where the hose would not be capable of correct installation.

Unfortunately I see hoses connected to hobs on a regular basis...often by homeowners and illegal gas workers. It's fair to say that 50% of gas leaks I attend are on the hob connection through this shoddy practice.

 

[brennan50]

gasguru are you sure hobs can be installed with a flexible hose?

 

[TCCHeating]

gasguru are you sure hobs can be installed with a flexible hose?

I think gasguru was very clear in what he said. Comply with the mi's and you can't go wrong! Even if the mi's say the hob can only be connected with an old bike tyre inner tube then that is final. However silly it may seem

 

[Gasguru]

Yes if you read the hob manufacturers manuals you'll find some will state they can be fitted with a flexible connection ie. a hose BUT as I stated before you must comply with the hose manufacturers requirements and for the vast majority of installations that rules out hoses. Inside the rubber hose is a metallic spiral hose...similar to a shower hose. If the hose is strained (and especially if it's overheated) the spiral can fail and the sharp metal edges can slice through the outer rubber hose.

http://www.dailyrecord.co.uk/news/scottish-news/cowboy-engineer-blew-up-couples-878546

Example of the hose spiral...

http://www.sgas.co.uk/wp-content/gallery/rogue-pipework/unsafe-situation-cooker-hose-failure.jpg



Give 'em a ring....

http://www.bowbros.co.uk/index-2.html