Gas pipe size

[lordyjordy111]

Hi
would any one mind checking my gas size calc.... changing the boiler to a similar rated new one but the existing pipe is mainly run in 22mm wich by my calcs is undersized. both current appliances work fine though?
the cooker is a big gas hob/oven rangemaster 110cm which i rated at approx 12kw(not sure if i'm right)
MY CALCS

Pipe run serving two appliances 1) 22kw boiler 2)12kw cooker

section lengths of pipe

A-B) 7.96M with 5 elbows so equivalent length 10.46m
serving 34kw which needs 3.23m3/h = 28mm pipe

section B-C main gas run to cooker is only short so 15mm

section B-D is main gas run to boiler 4.5m + 2 elbows = 5.5m so 22mm

am i close or completely out?

 

[Dotty]

You need a gsr in to look at your boiler. We cannot and will not give advice on the installation or repair of boilers for your own safety.

Please go to Gas Safe Register | Ensure your gas engineer is registered. or post a thread in the 'I'm looking for a plumber / gas engineer' section of these forums remembering to include your location. [DLMURL="http://www.ukplumbersforums.co.uk/im-looking-plumber-gas-engineer/"]I'm looking for a Plumber or Gas Engineer[/DLMURL]

If you are gsr please increase your post count to 10+ then send a private message to either Gas man or Redsaw who will then check you and then give you access to the gsr private forum.

Thank you.

http://www.ukplumbersforums.co.uk/central-heating-forum/42241-notice-gas-safety-related-advice.html