The Accidental Smallholder Forum
Smallholding => Equipment => Topic started by: elizasheep on November 16, 2011, 06:51:07 pm
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We've been using bottled gas for our cooker hob since moving here five years ago. I have always been underwhelmed by the heat output of even the biggest burners. At maximum, the flame is moderate according to what I have been used to in the past. I had been assuming that bottled gas just has less oomph, but now I think I was wrong. A friend reckons that they get much better performance on their much older hob. He said our inlet pipe was the right diameter, so it isn't that. I keep the burners on the hob clean. The cooker came with the house, but it is only about 9 years old now and is supposed to be a good one. On the plus side, it has an amazingly low simmer :D but I would like to be able to fry properly. I can't think what else is the problem. Might the gas regulator be causing the problem?
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almost certain you can get different flow rates also the rubber pipe might be decaying inside :farmer:
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We cook on red bottles, and have absolutely no problems. Of course it's worth checking the obvious things like regulators. One first check is which gas the regulator was designed for. It may say on it, but generally they're coloured blue for butane, and red for propane. One way to do a crude regulator test would be to light one ring, and check the flame height, then light all the other rings, and check if the flame height of the first ring has reduced substantially. If it has, try changing the regulator. However, if it doesn't change much, it's more likely to be your burners at fault, as I believe that you need to have them adjusted if you change from mains gas to bottled (certainly the manual for our cooker explicitly states that it's configured for using with bottled gas, and shouldn't be used on mains without adjustment). If your cooker has never had this done, this might well explain the problem.
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As Womble said, bottled gas comes in two flavours. The series of gases we use, methane, propane and butane, represent molecules of carbon and hydrogen which are progressively larger. The series continues and soon reaches octane being the reference compound for petrol, so it's a liquid.
Sorry about all the technical stuff. The point is that as the molecules of the different gases get larger they become easier to keep as liquids, i.e. not turn into gas.
If you regulator and hob expect to has a supply of propane and are being fed with butane, the pressure may be lower than required, hence no heat.
Check the documentation carefully. Alternatively contact the hob manufacturer to get their advice. There is no reason why the hob shouldn't produce as much heat as a natural (methane) hob.
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Butane, the blue one, is the densest and highest energy but has the highest boiling point. So the pressure from the cylinder drops sharply with temperature which is why outside storage tanks are always propane. Not only that but as the gas vaporises it cools the cylinder so you will sometimes see orange cylinders covered in frost.
You aren't allowed to keep the gas cylinders indoors any longer: my aunt Nellie was badly injured by such an explosion in her farmhouse at Sebergham. Being heavier than air leaking gas will gently roll across the floor towards the Aga before exploding. I have also seen people heating a cold butane cylinder on the gas ring that it supplies...
Change the regulator and see what happens, and grovel round the back of the cooker to see what gas it thinks it should be receiving
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I dont know anything more technical than just stating that my gas hob uses propane and its as good as any mains gas cooker I have had in the past. Sounds like there is something wrong with jetting or your regulator.
Baz
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Last year I had propane for central heating too - Mmm frosty cylinders mean big bills - we were burning 4 biguns a month.
I'd swear by propane for the hob though - just like normal gas for me and lasts for frinkin ages.
Baz
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Are you runing with one bottle or two? To get a good heat you need two large bottles going at one time. I run a catering trailer and if I use only one bottle you can really tell as the pressure is so much lower and everything takes longer to heat up.
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Our cooker used a propane hob and does a super job, when it was installed new last February the gas engineer kept having to remove the burners to set the burn level, the smallest burns really fierce (to much) the large centre hob not fierce enough, so they do have to be set up when comissioned :thumbsup:
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check the input on the unit it may have different settings for different gases if not the orifice on the burner has to be changed to the type of gas you are using the gases have different BTU values