# Gas Cooker Power Output

• posted

Hmmm, slightly off topic but here we go.

I have just had delivered, and installed, a new Gas Cooker. I am in the UK.

It seems to me that the cooker is woefully inadequate. A standard ring with a standard pan that fits the ring, will not make a pan of chips (french fries).

Similarly, the oven, which has a control up to Gas Mark 8, will not heat the oven higher than Gas Mark 5, and 45 minutes at Max failed to brown properly a Poussin for dinner tonight, and the garlic bread was similarly uncooked, so my breath is going to stink tomorrow.

But the question is, how might you measure the power output of such a cooker to determine whether there is or isn't a problem with it? All I know is that according to the Gas Safety Certificate given to me by the installers, it is rated at 9KWHr. (It has an oven and grill (mutually exclusive use), 2 standard rings, one small one and one large one. I haven't a clue what this 9KWHr figure actually means in practice)

Now, I know there are methods of checking microwave power by boiling a known quantity of water and timing it, so is there perhaps a similar method for a gas cooker? (Obviously more difficult than the Microwave because the efficiency of heating is going to be vastly different and very subjective).

Cheers,

Gareth.

• posted

Perhaps there's a conversion at

• posted

Thanks, but I need a way of determining my Cookers power output.

Gareth.

• posted

So 1 kWh is the energy equivalent of 3412.3 BTUs.

What's the resolution of your gas meter? IF you can determine the cubic feet per unit time, your gas company can tell you how many BTUs that is. Assuming your air is mixed right and the flame is blue, the efficiency should be near 100% of what the gas company sez.

Boiling the water gives you the EFFECTIVE usable energy transfer in the proper context. That's what really matters when cooking food.

1 BTU raises the temperature of a pound of water one degree F.

Bottom line is that you didn't get what you thought you bought. I'd contact the installer.

• posted

On Tue, 31 Jul 2012 19:47:18 +0100, "Gareth Magennis" put finger to keyboard and composed:

Do you mean 9kW?

- Franc Zabkar

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• posted

No. It took an hour to cook my Pouisson and Garlic Bread.

Gareth.

• posted

"Gareth Magennis"

** Get one of these;

The oven should heat to 250C in about 15 minutes.

I put 1 litre of tap water ( 13C ) in a 4 litre saucepan and heated it to boiling on a large ( 100mm dia ) burner.

That took 5.5 minutes.

Equates to 1.1kW being delivered into the water.

... Phil

• posted

Is it avilable on natural gas & propane versions? It may have the wrong orfices installed.

• posted

Presumably it's actually 9kW, not 9kWHr, given that the latter would be meaningless in this context.

Unless it has an externally flued oven, all the heat from the cooker is going into the room, and will heat the room up. Comparing how quickly the temperature rises with the rate when you use an electric heater of known power, would give a measure of the power of the cooker.

However, you seem to be describing a cooker with a significant problem. Unless this is some unapproved Chinese import with fake certification, my guess is that there's a gas supply problem. Either your local gas pressure is unacceptably low, or there's a blockage in the pipework (kinked flexible hose, or squashed pipe, or some such).

Sylvia.

• posted

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With my gas bills (Southern Gas) is included a complicated (time varying due to varying calorific value of the gas sources, assuming they are honest in this fudge factor) factor for multiplying gas cu-ft / cu-lt ? via kilowatt-hours etc to LSD. With nothing else using gas, including pilot lights if any, boil a litre of water and take measuremnts of the gas-meter before and after the boiling. So you then have the KWH required to raise 1 Lt from tap temp to boiling and the KWH of gas used

• posted

Thanks for all the suggestions.

OK, I've boiled a litre of water in a 2 litre pan on the large 100mm ring and it took around 6 - 6.5 minutes, kind of in the same ballpark as Phils results.

Thing is my probably 20 year old cooker had 4 small rings of the same size, but they were quite powerful, so my french fries experiment was done on one of the medium sized rings of the new cooker, and they are not powerful enough to cook them. So I was comparing Apples and Oranges there. The 100mm ring probably would do fine with a suitably larger pan, so perhaps there's nothing wrong up top.

The oven definitely has a problem, and I have noticed the floor pan above the burner is bent with a damaged philips screw holding it in, so someone has been messing with it. I will investigate this later.

Phils 250oC in 15 minutes is what I would have expected from my old cooker - this equates to Gas Mark 8. This one never got above Mark 5 despite 45 minutes on full blast. I believe the thermostat is reasonably accurate because it tallies with my common experience of putting a chicken in the oven at Mark 8 and Mark 5. The results last night were definitely Mark 5.

The cooker did come with an extra set of jets and some kind of choke (?) coupling for Propane gas - the packet is clearly marked as to what they are, the fitters pointed them out too, so I don't think the wrong jets are fitted.

I'll do the Gas meter calculation, probably over the weekend - will again run the oven on full for an hour and see how much gas it has used, and see if it has cooked my shoulder of lamb. I know for a fact it won't do roast potatoes right now. Bummer.

Thanks to all,

Gareth.

• posted

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Each burner should have a BTU/hr and/or kW rating associated with it. The manufacturer should have that information if it is not in the owner's manual. Then I would try to compare that to the BTU/hr rating was for the burners from your old cooker. If you don't have the manual, or if the manual lacks that information, I'd try calling an appliance parts dealer, and ask about what the rating of a replacement burner for the old cooker would be.

Did you install the cooker, or did the dealer? Likely Sylvia is right, and the installer squeezed the hose.

The simplest possibility is that the gas supply valve is not open all the way.

• posted

If it appears that the GAS appliance has been tampered with, it's an indicator that the appliance could be unsafe, and also that it's possibly been returned by a previous buyer when it was discovered that the output was lower than expected.

Undercooked food will make people very sick.

-- Cheers, WB .............

• posted

I came to this same conclusion today, and consequently contacted the installers to sort it out.

Cheers,

Gareth.

• posted

On Tue, 31 Jul 2012 22:44:14 +0100, "Gareth Magennis" put finger to keyboard and composed:

Kilowatt-hour is a unit of energy, not a unit of power. As such, it doesn't make any sense to rate a gas cooker in this way. That is unless you have something like a barbecue, and you are rating the energy capacity of the gas cylinder in an unusual way.

- Franc Zabkar

```--
Please remove one 'i' from my address when replying by email.```
• posted

I'm not sure how this cooker is built, but a common kitchen range could have two burners, a grill, and an oven.

Here in the (former) colonies the usual oven has a thermostat that allows setting the temperature up to at least 450°F (230°C for those using a real temperature measurement system). In the absence of a thermostat, oven temperature guages are available. If the oven cannot be heated to the appropriate temperature for baking, something would seem to be wrong. On the range I use the smaller oven will reach

400°F in less than 5 minutes - quite adequate for the kind of baking I do.

Similarly the burners (presumably what you call a gas ring) will bring a quart (liter to you) of water to a boil in about 10 minutes - about the same time it takes me to brown a pound (half kilo) of ground beef for whatever concoction I am preparing.

In the US gas appliances are set up for either natural gas (methane) or LP gas (propane). The two gasses require different orifice sizes due to the different energy content of the gasses. If a neighbor of mine was complaining about a problem such as you describe, I would suggest checking if the appliance was set up for propane rather than natural gas.

PlainBill

• posted

So if a cooker had Propane jets and was run on Natural Gas, would it run cooler or hotter?

(I'm running on Natural Gas)

Cheers,

Gareth.

• posted

Ah, think I can answer my own question. The jet fitted to the 100mm burner is stamped 115. The spare jet provided with the cooker for use with Propane is 085. Propane requires a smaller jet.

The other burners have similar outcomes. So it looks like the cooker is not incorrectly fitted with jets for use with Propane. I haven't checked the oven one as that would entail removing the burner cover that has been tampered with, thus destroying the evidence that I have been supplied with a "customer return".

Gareth.

• posted

What does the manual say is the correct orfice?

• posted

There is no technical information in the user manual, nor any information on the manufacturers website.