Electric cooker temperature

[Gary WoodingParticipant @garywooding25363]

From time to time, SWMBO complains that items such as roast potatoes won't brown. She's adamant that, although she does nothing different, on some days (usually a Sunday) the oven doesn't appear to reach the correct temperature and that's why the potatoes won't brown.

I thought that the mains voltage was stringently regulated, so can anybody suggest why she is observing this problem?

[Gary WoodingParticipant @garywooding25363]

[richardandtracyParticipant @richardandtracy]

I think the voltage is supposed to be 220 +/- 5%, not the 240 that it used to be.

Is there more in the oven during weekends? If there's more volatile stuff (water being one) in the oven, it could make for colder spots. Else if there are more bits to put in the oven (like stuffing, onions etc) all at different times, then open the door more often could make for a change.

Or possibly your oven hates working on Sundays, I do.

Regards

Richard.

[Simon CollierParticipant @simoncollier74340]

Same variety of potatoes and a type suitable for roasting? Pre- heat oven properly? Metal dish. Good amount of oil/fat. Pretty hot, maybe 210-220. Baste and turn once or twice. For a crispier but soft spud, par boil till surface starts to flake.

[herbert punterParticipant @herbertpunter99795]

You could buy a digital thermometer from eBay, about five quid, and monitor it.

Then you would have some idea of what’s happening.

Bert

[David Standing 1Participant @davidstanding1]

Dodgy thermostat?

If that is ok, does the oven have other stuff in with the roast spuds? To crisp properly, they probably want to be in on their own.

[KWILParticipant @kwil]

Ordinary oven or fan assisted? Non fan asisted will have varying temperature distribution if the it is chocker with lots of dishes.

[SillyOldDufferModerator @sillyoldduffer]

Posted by Gary Wooding on 05/04/2018 10:16:20:

…

I thought that the mains voltage was stringently regulated …

Depends what you mean by 'stringently regulated'. UK supply can be within a 16% range: 230V +10% to 230V -6%.

Most of the time the voltage in my home is higher than 230V. It's 238V at the moment. Most of the time I cook with extra volts available and that sets my notion of my electric cookers performance.

It's noticeable that my cooker underperforms on cold Sunday lunchtimes and at other times when demand is high. I've never measured the voltage but it could be as low as 216V and still be in spec. As I live in a village and share a 4MW pole pig with many neighbours, it's not unlikely that locally it might occasionally dip below the minimum. That said I've not had a proper 'brown-out' in the 30 years I've lived here. (Happened sometimes in Malta during the early sixties: all the lights in the town dimming for several minutes caused no alarm!)

Dave

[Martin Johnson 1Participant @martinjohnson1]

The mains voltage is the same, the oven is the same, the potatoes might even be the same. However, the thermostat is a cheap piece of Chinese junk that will drift off specification quite quickly, and that is probably your (well, her's actually) problem. They are quite cheap to replace, especially if you go for non OEM spares.

Martin

[David Standing 1Participant @davidstanding1]

Posted by Martin Johnson 1 on 05/04/2018 10:44:04:

The mains voltage is the same, the oven is the same, the potatoes might even be the same. However, the thermostat is a cheap piece of Chinese junk that will drift off specification quite quickly, and that is probably your (well, her's actually) problem. They are quite cheap to replace, especially if you go for non OEM spares.

Martin

Are you not married? If Mrs Wooding has a problem, so does Mr Wooding

[SamsarandaParticipant @samsaranda]

My wife also complains on the performance of our oven on Sundays, particularly cold winter Sundays, and public holidays such as Xmas day, so I suspect that it is down to supply voltage dropping but probably still within spec. The other complaint she has with our oven is that her cakes (she is famous for the quality of her cakes in our village) sometimes fail to rise, at random times. She has decided that the blame is not with the oven or other variables but lies squarely with me, I am supposed to have opened the back door in the kitchen excessively causing a variation in temperature which causes the cake to fail. I know it is an argument that I won’t win so when cake baking is scheduled I arrange to lock myself in my workshop for the duration, no hardship there.

Dave W

[not done it yetParticipant @notdoneityet]

First question is: Does the thermostat operate? If not, the oven is not maintaining the temperature at the set point and there is more energy being lost than inputted.

Easy to observe, And yes, from max to min supply voltage cooker could be down bt 15% of its maximum power. Actual voltage at the oven elements might even be a bit lower if several kilowatts are being consumed elsewhere within the cooker, I suppose. Guaranteed supply voltage is to the meter, no further…

If the supply voltage actually falls below the minimum, the supply could be connected to a different point on the windings of the local transformer.

[Johnboy25Participant @johnboy25]

Can you check continuity of the heater element? Depending on the make/design of the oven there may be one or two elements. I have had experience of elements going open circuit when they heat up giving you a false impression that it ok.

John

[not done it yetParticipant @notdoneityet]

Posted by Johnboy25 on 05/04/2018 11:11:25:

Can you check continuity of the heater element? Depending on the make/design of the oven there may be one or two elements. I have had experience of elements going open circuit when they heat up giving you a false impression that it ok.

John

Easy enough to check the meter rotor speed (or flash rate on a digital meter), at turn-on and at high temperature?

[Gary WoodingParticipant @garywooding25363]

Hmm, thanks for the lots of suggestions.

I discarded a faulty thermostat or element as possible causes on the grounds that the problem is intermittent – occurring, at most, only once or twice a month. It is a fan oven and the normal procedure is to first cook the meat and anything else that doesn't need browning, then remove them and turn up the heat for the potatoes. It normally works fine except that sometimes she moans about the meal being late because the tatties won't brown.

The element is relatively new, having been replaced about 8 months ago, so I'm inclined to blame a reduced supply voltage.

[Clive HartlandParticipant @clivehartland94829]

OK, same old story. The fan is running slow and is basically US, Easily changed without taking oven out of housing but when taking wires off put a peg on them to stop losing the wires back inside. There are several concerns on the internet but the one I use is Espares. You need the oven type and serial number and a chat to the nice lady will get you what you want.

I found that the bearings goo up and do not run freely.

[HOWARDTParticipant @howardt]

Use an oven thermometer to check temperature while cooking. Verify thermometer how ever you want, eg boiling water

[BazyleParticipant @bazyle]

Do you have a spare blowtorch you can give her? Trendy cooks have such things for caramelising sugar topping etc. paint it pink and say it is a special cook's one from France.
Problem may be that turning up the heat doesn't go to the same setting every time.

[Ian S CParticipant @iansc]

When I first moved to Darfield in 1984 the lights would dim, the stove not heat, the electric jug took a long time to boil, all in a period about 1hr before meal time, everyone had the stove on, and in the winter electric heaters. A check with the multi metre showed that the voltage dropped to 185 volts from the normal 240V. A couple of years later a new district sub station was put in, and since then there has been no noticeable fluctuation in voltage. I would be blaming the supply network.

Ian S C

[Mike CrossfieldParticipant @mikecrossfield92481]

A while back my wife complained about her cooker apparently not reaching temperature. The fairly new high spec. electric cooker has two fan ovens, one large and one small. She found she got different results in them despite setting the same temperature, the small oven apparently being cooler than the large oven. Also variable results depending on quantiles of food in them. To try to get to bottom of the problems I ran a series of tests with thermocouples in the ovens, over a range of temperature settings. What I found was that it took a much longer time for the set temperature to be reached on a tray in the centre of the oven than indicated by the oven thermostat, and the problem was worse in the smaller oven which had a smaller heating element. Things also got worse as the temperature setting was increased and the loading of the oven increased. My conclusion was that the oven thermostat effectively measures air temperature at some remote point remote rather than the “body” temperature of the oven, and that there is a significant lag before the true required temperature is reached within the cooking vessel.

To give an example: In the case of my cooker the small oven, which has a smaller element than the large oven, took 3-4 cycles of the thermostat before a temperature within 5 degrees of the demanded temperature of 180 degrees was reached. The large oven took 2-3 cycles to reach temperature. This was with effectively empty ovens.

My wife now allows a few minutes extra time after the thermostat light on the oven has gone out for the first time before assuming that the required temperature has been reached, and she now gets consistent expected results.

[Gordon WParticipant @gordonw]

Just to confuse things- we have the same problems, but it is a gas oven, bottled gas. Wife blames me for door opening etc.. Will check the fan, electric of course, but does seem ok.

[larry PhelanParticipant @larryphelan54019]

Best way I know to get spuds to brown well is to put them in the oven in the usual way,and then go out to the workshop for a few minuets just to finish off that little job. By the time you get back to the kitchen,your spuds will be well and truly browned,perhaps even black ! At least,they will be different. Some might not like them,but you can,t please everyone.

From experience,many times over,I can vouch for this method,but it can work out a bit expensive if you like spuds.

Some cooks are a bit iffy about using this approach,so check first.

[not done it yetParticipant @notdoneityet]

For roasties, my wife reckons the goose fat from the Christmas dinner cooking is the bees knees for getting her spuds perfect almost every time. We don’t have roasts that often and there is always spare goose fat stored in little packages in the freezer. I’m not complaining.

[Phil WhitleyParticipant @philwhitley94135]

Sounds like it could be localised volts drop, some may have noticed that modern ovens tend to top out at lower temps than they used too. (190, instead of 220). Oven stats are either liquid or gas operated, and tend to simply quit altogether, they used to be adjustable, but I doubt they are today. Incidentally, Nominal UK mains voltage is 240V, due to EU harmonisation, engineers were told that if asked, they had to say that the voltage was 230V all over the EU. The engineers gave this request VERY short shrift!

"Just as it was in 1960, the supply voltage to domestic properties in the UK is still nominally 240 V AC at 50 Hz, although the declared voltage in the UK is now 230V AC +10% to -6%. Historically the domestic voltage was 240 V +/-6% (and 415V 3phase), whilst continental Europe was 220V (380V 3 phase)."

[Brian Sweeting 2Participant @briansweeting2]

If the volts go down then the amps go up to compensate.

Start with a new thermostat.

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