Earth Notes: On the Siemens KG34NA10GB Upright Fridge/Freezer: Review

Updated 2023-02-06 10:24 GMT.
By Damon Hart-Davis.
Read why we felt cheated after upgrading our upright fridge-freezer to save energy and for more freezer space. #frugal #fridge #freezer
fridge freezer interior Siemens KG34NA10GB
Selecting an energy-efficient replacement fridge/freezer, that actually did what it says on the tin, proved more challenging than it should have been.

Product: Siemens KG34NA10GB

fridge freezer interior Siemens KG34NA10GB
Upright frost-free fridge/freezer with wine rack.
  • Brand:
  • Energy consumption: EU efficiency category: A+
  • Colour: white
  • MPN: KG34NA10GB/02
  • OutOfStock
  • GBP515 valid at/until:
Review summary
  • Siemens KG34NA10GB
  • Reliable, nice features such as bottle rack and freezer door alarm, but infuriatingly over 30% more energy consumed than the brochure indicated; I feel deceived.

    More space, half the power consuption of our previous smaller fridge/freezer, auto-defrost, with useful fridge-above-freezer arrangement to minimise bending down.

  • Rating: 3.5/5
  • Published:
  • Updated:

Old Guzzler

Our old upright fridge/freezer was a Zanussi "ZFC 62/23 FF" bought seven or eight years ago and still working OK.

However, at ~2kWh/day electricity consumption out of a house total of 7kWh, and given that we wanted a bit more freezer space, and given that we'd just put up a solar PV microgeneration system on the roof that our old machine would consume the entire output of, we decided that it was time for an upgrade.

The Zanussi fridge and freezer gross capacities were 175l and 65l respectively (170l and 50l net). The Zanussi had a nominal 1.7kWh/day power consumption. though it was measured to be 2kWh/day with a PM230 plug-in power meter.

Bricks and Mortar

We spent a long time on-line and visiting bricks-and-mortar stores looking for the replacement. I like the Zanussi brand in terms of cost and reliability, but we could not find anything by them that was suitable, which meant:

We did not like anything that we saw to start with, and initially hoped that we might find something in the £350 range. We checked out John Lewis and Waitrose, Boots, Currys/Dixons, Argos, various on-line price-comparison sites (though I loathe them), etc, etc, over the course of a few weeks.

Very few sites allowed us to sort or filter by energy consumption nor in particular by Energy Savings Trust approval. None filtered by capacity, which is daft, and would have saved much time and effort. Descriptions and ratings were largely consistent and clear, though Argos claims one of their appliances would use 0.88kWh/year, which would be miraculous! Retailers: please allow sensible sorting and filtering!

The John Lewis Direct site, from which we bought in the end, was nothing special but it worked. John Lewis in general is a well-run ethical company that we often use (disclaimer: and for which I worked part-time as a teenager). Apart from anything else we were happy to let them take away our old fridge for recycling, trusting them not to fly-tip it for example! Their £9 disposal charge was a little higher than some others', but the delivery charge was zero, and the appliance price of £524 OK.

You'll gather that we could not get frost-free and 90l+ freezer capacity and a decent fridge capacity and a brand with a good reputation for £350. Never mind with a supplier that we'd dealt with before and trusted. So the JL and Siemens brands were very helpful in that respect, and being able to look at the Siemens appliance in our local John Lewis department store in Kingston was also confidence-building.


The Siemens fridge and freezer gross capacities are 186l and 109l respectively (186l and 88l net), and a nominal 0.75kWh/day power consumption.

One thing that the extra freezer space will be used for is about-to-expire supermarket bargains that loss-lead rather than land-fill, and bulkier items such as bread.

Energy Use Too High

As of the first week of use I had not yet observed a consumption as low as the specified 0.75kWh/day (though not over 1kWh/day either), which is disappointing, and as of July/August I was seeing a typical usage of ~1.1kWh/day or a little over measured three different ways, so an engineer has been to check over the appliance, and thinks that possibly the auto-defrost is not doing enough, thus making the cooling less efficient.

Everything is completely functional and safe, just using more power than it should and than we bought it for.

I will try to test this theory by completely defrosting the entire fridge/freezer with power off over a couple of days, and seeing if it reverts to a lower daily consumption afterwards. If so, we may need to fix the defrost mechanism.

'Before' measurements: in the 24 hours up to 2008-08-27 17:20 BST, the fridge/freezer consumed 1.09kWh, 45% above spec. In the following 24h it used just under 1kWh. (I bumped the temperatures up one notch prior to emptying to save energy.)

The appliance was left off from 2008-08-28 17:20 BST to 2008-09-01 07:50 BST, with the doors and drawers open as appropriate to allow a full defrost.

'After' measurement: in the 24 hours (+18m) up to 2008-09-02 17:38 BST the fridge/freezer consumed 1.15kWh. In the next 24 hours it consumed ~1.07kWh. In the next 48 hours it consumed ~2.05kWh (to a total of 4.56kWh over 48h). In the next 72 hours it consumed ~3.18kWh (to a total of 7.74kWh over 168h).

After some more visits and measurements, and unsatisfactory talk from Siemens' tech staff suggesting that the figures that it publishes/advertises are meaningless non-real-world lab values and that Siemens does not intend to stand by them... Then me pointing out that trading standards officials might take a dim view... And some final fiddling around and addition of sealant in strategic places... As of a coldish 2009-02-03 some time after the last engineer visit the appliance seems to be consuming a shade under 0.9kWh/day. Over the course of nearly two weeks consumption was more like 0.91kWh/day. Not what was advertised, and I'm not entirely happy, but I'll live with it. It's just at the edge of believable error from the meter (~10W). But I may well never buy another Siemens appliance.

More Measurements

fridge/freezer energy consumption over one day

See the above graph and .csv spreadsheet/data of 1 minute samples by an AlertMe monitoring system for 2011-09-04: mean 42W (1.02kWh/d), max 356W, typically 0W or 75W.

On 2011-09-05 I gently dusted the coils on the rear of the fridge/freezer to see if there is any discernible reduction in power consumption. The next full day's .csv actually shows a slight increase and then back to 1.01kWh the following day .csv graph .png, average over 10 days was 44.6W or 1.07kWh/d or taking the last 6 of those days to allow things to have settled after dusting/moving 42.9W or 1.03kWh/d, of which the lowest day (2011-09-08) was 39.4W or 0.945kWh/d.

Over more than a month (2011-09-04 to 2011-10-14 inclusive) the mean consumption was 42.5W or 1.02kWh/day. There is a possible slight downward trend with the cooler weather, with the lowest day's consumption being seen on 2011-10-12.

2022-10: Yet More Measurements

In October 2022 I received a Local Bytes power monitoring smart plug. And the first serious bit of appliance monitoring was for an update on this fridge/freezer!

Raw data (.log.gz) from 7th, 8th, 9th, 10th. See all artefacts.

LBplug 2022 10 07
Data collected from first day (2022-10-07) up to midnight UTC for fridge/freezer. Notice the sometimes-visible high compressor start-up power demand of ~800W, possible ~200W defrost activity, and ~80W normal running consumption on a typical ~50% duty cycle. Sampling is at 1-minute intervals. All times UTC.
LBplug all
Data collected from 2-and-a-bit days (starting 2022-10-07) up to midnight UTC for fridge/freezer. Notice the sometimes-visible high compressor start-up power demand of ~800W, possible ~200W defrost activity every ~12h followed by a longer compressor run possibly to remove the extra heat injected, and ~80W normal running consumption on a typical ~50% duty cycle. Sampling is at 1-minute intervals. All times UTC.

Looking at the final Total readings for the 7th/8th/9th implies consumption on Saturday 8th of 1.221kWh and on the 9th of 1.220kWh:

2022-10-07T23:59:01 {"StatusSNS":{"Time":"2022-10-08T00:59:01","ENERGY":{"TotalStartTime":"2022-10-05T19:17:26","Total":0.698,"Yesterday":0.584,"Today":0.114,"Power":193,"ApparentPower":193,"ReactivePower": 0,"Factor":1.00,"Voltage":248,"Current":0.778}}}
2022-10-08T23:59:01 {"StatusSNS":{"Time":"2022-10-09T00:59:02","ENERGY":{"TotalStartTime":"2022-10-05T19:17:26","Total":1.919,"Yesterday":1.214,"Today":0.121,"Power":194,"ApparentPower":194,"ReactivePower": 0,"Factor":1.00,"Voltage":249,"Current":0.780}}}
2022-10-09T23:59:01 {"StatusSNS":{"Time":"2022-10-10T00:59:00","ENERGY":{"TotalStartTime":"2022-10-05T19:17:26","Total":3.139,"Yesterday":1.230,"Today":0.112,"Power":191,"ApparentPower":191,"ReactivePower": 0,"Factor":1.00,"Voltage":247,"Current":0.773}}}

So ~20% higher than 11 years ago, which is not too bad. Yes, I should clean the coils at the back again.

Lamp Replacement

The right-hand-side fridge lamp expired and was replaced with a Philips 5W LED (E14 pygmy) lamp for £5 from John Lewis 2018-12. The left-hand-side lamp is one of the few incandescents left in the house, the oven and microwave oven being honourable exceptions.

The left-hand-side lamp expired in 2020-10, and we are replacing from Amazon (MiniSun 3w High Power SES E14 LED Pygmy Energy Saving Long Life Light Bulb - 3000K Warm White) for £5. The old incandescent was 15W, so 1.5W would nominally do! (The microwave lamp recently failed too, and we have bought but not yet fitted the replacement...)

~1634 words.