Electric oil filled radiator - partially filled?

[pochisoldi]

I've bought an oil filled radiator as an "emergency backup".
Can anyone tell me if an oil filled radiator is supposed to be full of oil, as this one is obviously partially filled - you can hear the oil sloshing around, and cycles on the overheat thermostat.

Leave the thing on the 2kW setting and it cycles: on for about 70-80seconds, then off for 5 to 6 minutes.
I've effectively bought a 350W heater!

The thing is going back, and I want to know if I can use the "slosh" test to determine if the replacement is equally as faulty, rather than having to repeat the rigmarole of take home/unpack/screw feet on/plug in/dismantle/re-box/return to shop.

For the record "on/off" has been checked using a plug in power meter - the consumption drops to zero, and no amount of knob twiddling restores power to the elements.

PochiSoldi

[Mike4]

I'd say there needs to be an expansion space (pocket of air) above the oil, so any oil-filled rad passing your slosh test would be dangerous to use.

[servodude]

I've bought an oil filled radiator as an "emergency backup".
Can anyone tell me if an oil filled radiator is supposed to be full of oil, as this one is obviously partially filled - you can hear the oil sloshing around, and cycles on the overheat thermostat.

Leave the thing on the 2kW setting and it cycles: on for about 70-80seconds, then off for 5 to 6 minutes.
I've effectively bought a 350W heater!

The thing is going back, and I want to know if I can use the "slosh" test to determine if the replacement is equally as faulty, rather than having to repeat the rigmarole of take home/unpack/screw feet on/plug in/dismantle/re-box/return to shop.

For the record "on/off" has been checked using a plug in power meter - the consumption drops to zero, and no amount of knob twiddling restores power to the elements.

PochiSoldi

I can't recall there being an audible "slosh" but I can remember feeling the stuff moving as you carry them about; so not completely full (and I can imagine there's a need for room to expand)

It sounds like yours has a dodgy thermostat (or a fault with the element causing it to trip off)

The power rating is only relevent for when it is delivering power to the element - once it's at the target temp it should stop taking any power until it has cooled down sufficiently; the job of the oil is to act like a thermal store to smooth out that cycling

can you change the target temperature? perhaps the setting indicated is not trustworthy

[csearle]

Most of the ones I've come across make a slosh and a gurgle if removed too far from a perpendicular to our Earth's fair surface. C.

[pochisoldi]

There's nothing wrong with the manual thermostat - it's cycling on the overheat stat which has a heavier click.
The shutdown occurs regardless of the manual setting.

The unit is so cool it can be held indefinitely - the instructions tell you to let it cool down before moving!

I left the thing running for an hour plugged into the power meter and the thing pulled 0.4kWh, with the thermostat set at halfway.

For the record it's a CYBL20-9 bought from Toolstation.

PochiSoldi

[BullDog]

Definitely faulty if the overheat thermostat is tripping. It just shouldn't do that unless there's a fault with the regular thermostat. Should work quite happily with the room thermostat set to maximum. Overheat thermostat is a safety device and normally it shouldn't operate at all.

[fisher]

There's nothing wrong with the manual thermostat - it's cycling on the overheat stat which has a heavier click.
The shutdown occurs regardless of the manual setting.

The unit is so cool it can be held indefinitely - the instructions tell you to let it cool down before moving!

I left the thing running for an hour plugged into the power meter and the thing pulled 0.4kWh, with the thermostat set at halfway.

For the record it's a CYBL20-9 bought from Toolstation.

PochiSoldi

The 5th review down for this radiator on the Toolstation site says something similar. Looks like this is a recurring fault with some of these:

"The radiator had a fault with the thermostat which made it cut out before it had reached temperature. This was borne out by its replacement which was an entirely different brand which works as expected"

https://www.toolstation.com/oil-radiator/p52406

[bungeejumper]

Most of the ones I've come across make a slosh and a gurgle if removed too far from a perpendicular to our Earth's fair surface. C.

Oh, indeed. And that can also set off the anti-tilt pendulum switch, which I think is now fitted to all such heaters. If it gets knocked over, it switches itself off.

That wasn't the problem with ours, which was a chain store own-brand jobbie. Sure enough, it was one of the two thermostats that had failed. A replacement stat only cost about £6, but it was a right fiddle to fit. (High current, cramped wiring space, unimpressive standards of insulation.) I'm a believer that everything is worth one attempt at fixing, but I'm not sure I'd bother if it ever happened again.

Send it back. They won't argue.

BJ

[Itsallaguess]

For the record it's a CYBL20-9 bought from Toolstation.

The 5th review down for this radiator on the Toolstation site says something similar. Looks like this is a recurring fault with some of these:

"The radiator had a fault with the thermostat which made it cut out before it had reached temperature. This was borne out by its replacement which was an entirely different brand which works as expected"

https://www.toolstation.com/oil-radiator/p52406

Screwfix sell the same radiator, and there's a long list of negative reviews related to similar 'lack of heat' issues -

https://www.screwfix.com/p/cybl20-9-freestanding-9-fin-oil-filled-radiator-2000w/947ky

I suspect this is a particular quality-control issue where, if one works well 'out of the box', as some of them clearly do from reading some of the above reviews, then it's likely to be fine during the rest of the ownership period, because there's no sign in the above reviews of time-based issues, and all the problematic ones seem to be problematic from the start.

Given that, I'd be willing to give a swap-out for the same brand a go, and ask them to open it in the shop and prove a quick heat-cycle. Hopefully you'll be able to see and be satisfied with a working one, and you can then take it away with a little more confidence...

In my experience, both Toolstation and Screwfix are very good with 'not working out the box' issues like this, so I expect you'll find a sympathetic ear if you take this one back and highlight the similar review-based issues...

Cheers,

Itsallaguess

[pochisoldi]

The "400W" grey heater went back to Toolstation, and was replaced by a "550W" white version from Screwfix - both cycling on the overheat thermostat, with the Screwfix unit getting warmer than the Toolstation one.

So it's back to the shop again in the hope of getting a working unit.

[jaizan]

What's the point in having oil in an electric heater anyway ?

A 1000W heater will consume 1000W and put out 1000W, whether it's full of oil or has none. All the oil does is just slow down the response of the thing.

[Mike4]

What's the point in having oil in an electric heater anyway ?

A 1000W heater will consume 1000W and put out 1000W, whether it's full of oil or has none. All the oil does is just slow down the response of the thing.

Well without the oil to convect the heat to the whole of the surface area of the radiator the heater element would overheat.

But a related question I've often mused over is why oil, not water with a dose of corrosion inhibitor? Have you seen the price of a litre or two of Castrol GTX?!

[BullDog]

What's the point in having oil in an electric heater anyway ?

A 1000W heater will consume 1000W and put out 1000W, whether it's full of oil or has none. All the oil does is just slow down the response of the thing.

Well without the oil to convect the heat to the whole of the surface area of the radiator the heater element would overheat.

But a related question I've often mused over is why oil, not water with a dose of corrosion inhibitor? Have you seen the price of a litre or two of Castrol GTX?!

Probably...... because water bolts at 100 degrees C and the water next to the element most likely would seeing that before convecting away. And in a thermostatic failure the heater would be pressurised by the resulting steam and you effectively have a bomb in the room waiting to explode.

[Mike4]

Well without the oil to convect the heat to the whole of the surface area of the radiator the heater element would overheat.

But a related question I've often mused over is why oil, not water with a dose of corrosion inhibitor? Have you seen the price of a litre or two of Castrol GTX?!

Probably...... because water bolts at 100 degrees C and the water next to the element most likely would seeing that before convecting away. And in a thermostatic failure the heater would be pressurised by the resulting steam and you effectively have a bomb in the room waiting to explode.

That's a good point. I would imagine the boiling point of oil is way higher than 100c. But the way to mitigate the boiling problem is to fit. pressure relief valve to let the steam out. This in turn presents a scalding risk which needs managing so all in all, using oil must be the most cost effective solution.

What IS the boiling point of oil anyway?!

[servodude]

Probably...... because water bolts at 100 degrees C and the water next to the element most likely would seeing that before convecting away. And in a thermostatic failure the heater would be pressurised by the resulting steam and you effectively have a bomb in the room waiting to explode.

That's a good point. I would imagine the boiling point of oil is way higher than 100c. But the way to mitigate the boiling problem is to fit. pressure relief valve to let the steam out. This in turn presents a scalding risk which needs managing so all in all, using oil must be the most cost effective solution.

What IS the boiling point of oil anyway?!

If it's anything like cooking oil about 300deg - smokes a bit before that based on what's in it.

[Dicky99]

What's the point in having oil in an electric heater anyway ?
All the oil does is just slow down the response of the thing.

For that reason. What's the point of having a slab of concrete in a storage heater.

[DrFfybes]

What's the point in having oil in an electric heater anyway ?
All the oil does is just slow down the response of the thing.

For that reason. What's the point of having a slab of concrete in a storage heater.

I thought they were being rhetorical and had missed the smiley.

But them I'm kind that way

[pochisoldi]

What's the point in having oil in an electric heater anyway ?

A 1000W heater will consume 1000W and put out 1000W, whether it's full of oil or has none. All the oil does is just slow down the response of the thing.

Let's compare a 1kW fan heater and a 1kW oil filled radiator.
Both get the area around the heater up to the temperature set by the thermostat.

The fan heater stops, and heat emission stops dead. The temperature reduces to the "turn back on" level and heat generation recommences at full pelt.
The oil filled heater stops, and heat emission continues. The temperature slowly reduces to the "turn back on" level and heat generation recommences, ramping up slowly.

The step change in heat emission from a fan heater when the thermostat switches on or off is more noticeable than the gradual change seen with an oil filled heater. You can effectively get away with running an oil filled radiator at a lower thermostat setting because the slow rise and fall is less noticeable than the harsh all or nothing of a fan heater. You have to set the fan heater to a higher temperature to maintain the same level of perceived comfort.

[jaizan]

Let's compare a 1kW fan heater and a 1kW oil filled radiator.

The fan is not mandatory.

I have 2 electric convector heaters with no fan*.
In most instances, the difference in performance between these and an oil filled heater will be so marginal as to not make it worth the extra expense of oil filling.


[*I do not heat my house with electric. These were issued FOC after a builder dug through the gas main in the village a few years ago & I keep them in case of central heating failure]

[pochisoldi]

Let's compare a 1kW fan heater and a 1kW oil filled radiator.

The fan is not mandatory.

I have 2 electric convector heaters with no fan*.
In most instances, the difference in performance between these and an oil filled heater will be so marginal as to not make it worth the extra expense of oil filling.


[*I do not heat my house with electric. These were issued FOC after a builder dug through the gas main in the village a few years ago & I keep them in case of central heating failure]

Fan heater, convection heater - who cares - an oil filled radiator will take longer to warm up, and to cool down, combine that with the fact that humans are relatively insensitive to small changes in temperature, this means that you can get away with setting a lower temperature on an oil filled radiator and still feel comfortable.
Alternatively you spend the same amount of money and feel warmer and more comfortable.

Yes a 1kW fan heater, 1kW convector and an 1kW oilfilled radiator will all give out 1kW of heat for 1kW of electrical energy (less a few watts for the motor), but they all differ in how that 1kW of heat is distributed over time.