Silent thermostat

Our bedroom gets very cold at night, due to having unheated spaces on 5 of it's 6 sides, despite double glazing, cavity wall insulation, loft insulation and insulation in the floor. I don't want to run the central heating all night, partly because it's wasteful to heat the whole house for one room and partly because it was installed by an imbecile and it clanks and clonks as it heats up and cools down and keeps us awake. I'm already wearing a tracksuit under a 13.5tog quilt, so more bedding isn't really an option.

So ... I bought a Dimplex 2kW convector heater to have on at night, thinking it would be relatively silent. Wrong. The thermostat in it reminds me of the Rank Organisation's gong in the credits of their movies. So, we're lying there wide awake (nice and warm, mind) listening to this thing going *TICK*, long pause, *TOCK*, long pause,

*TICK*, long pause, *TOCK*, long pause, *TICK*, long pause, *TOCK*, long pause, *TICK*, long pause, *TOCK*, long pause, *TICK*, long pause, *TOCK*, long pause, *TICK*, long pause, *TOCK*, long pause, *TICK*, long pause, *TOCK*, long pause, *TICK*, long pause, *TOCK*, long pause, *TICK*, long pause, *TOCK*, long pause, *TICK*, long pause, *TOCK*, long pause, *TICK*, long pause, *TOCK*, long pause, *TICK*, long pause, *TOCK*, long pause, *TICK*, long pause, *TOCK*, long pause, *TICK*, like a bloody deranged slow-motion grandfather clock.

So, does anyone know of a plug-in thermostat that will switch 2kW, but above all must be silent. TLC have this one;

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looking at the instructions, it too ticks. And my experience of the longevity of Smith Instruments domestic timers and the like is not good.

Reply to
Huge
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I don't know of any commercially available electronic thermostats that will not have an audible click, a bimetallic strip or latching relay (both mechanical) are the cheapest way of switching lots of power. I have built such systems in the past using solid state relays which are silent, but would be very expensive commercially.

Have you thought about an electric blanket? You can throw off all that excess bed covering weight and still be nice and toasty. A darn sight cheaper to run than a 2kW heater! I reckon ours uses less than a unit per night.

Dave

Reply to
Dave Gibson

[27 lines snipped]

I've never been very happy about the idea of electric overblankets. Are they safe?

Reply to
Huge

Ear-plugs? but then you won't hear the smoke alarm...

Reply to
Malcolm Stewart

Precisely.

Reply to
Huge

Yes. Well, at any rate, you don't hear of too many electrocutions or fires caused by them.

Reply to
Set Square

The only time that I have come close to dying in a fire, it was caused by one of these things. During the night it must have been too hot, and I managed to kick it and a pillow off the bed. The blanket folded up, the pillow landed on the blanket. I woke up to the smell of burning and a room full of smoke. The blanked had folded into half and the pillow had insulated a portion of the creased blanket allowing it to overheat.

It was well ablaze by the time I woke up and I reckon I was lucky to have woken at all.

All at a friends house who ended up being most apologetic about the incident. Not their fault, but IMO the damn things are inherently unsafe.

Reply to
Steve Firth

Yes. But like all electrical items you have to treat them with respect. Always buy new and follow the instructions carefully (which are only common sense instructions).

By law all electric blankets sold have to be BEAB approved and have built in overheat protection. They also monitor earth leakage and check for breaks in the circuit continuously.

They are so robust you can wash them in a washing machine, although personally we don't. We replace ours every 5 years as a matter of course.

To be absolutly straight, yes, they have caused fires, and people have died using them, but in all cases blankets have been blatently faulty and 99% were over 10 years old. I believe about 20 people a year in the UK die using them.

Compare this with fatalities caused by faulty heaters.

Using one is safer than crossing the road, but you have to weigh up the pros and cons in your own mind.

HTH

Dave

Reply to
Dave Gibson

In message , Huge writes

BTDTBTTS.

An oil-filled electric radiator may be a better solution. From memory, the thermostats are a lot quieter, if only because they are in a big empty (almost) metal "sounding" box. Also the higher thermal mass means the stat operates much less frequently. Steadier heat output as well.

Reply to
Steven Briggs

My experience of falling asleep on an underblanket (accidentally left switched on) is that you will die of overheating first. However, they do a good job of taking the chill off the bed itself, and you should not feel cold while you fall asleep. Two people under a winter rating duvet ought to get through the night without discomfort even in a cold room.

[Alternatively, why don't you move to one of your other gazillion bedrooms when it's chilly ?!]
Reply to
John Laird

Which is more people than die each year that will be saved by the new electrical safety regs to be introduced shortly. And guess what? Those safety regs do not cover electric blankets or any other type of utility device plugged into the mains.

PoP

Replying to the email address given by my news reader will result in your own email address being instantly added to my anti-spam database! If you really want to contact me try changing the prefix in the given email address to my newsgroup posting name.....

Reply to
PoP

I would be seriously considering an exorcist if I were you.

ATB

Kris

Reply to
Kris

[snip]

If the thing is 2KW capacity and is cycling the thermostat then it is running at less than 2KW average. You can gain some idea of the actual power by estimating ON/(ON+OFF).

If that is the case then it might be possible to run it at a reduced mains voltage such that it produces the same avg output power without ever tripping the thermostat (turn the stat up full anyway). eg, P= V-squared/R, so running at (say) 0.707x normal mains voltage would produce an average of 1KW output from a 2KW heater.

TRIAC power regulators are devices that produce an effective reduction of the AC voltage into a resistive load (silently).

See part numbers 291-500 or 291-511.

291-511 is interesting because it also allows attachment of a thermistor for temperature control.
Reply to
Tony Williams

We have seperate quilts on a 6' bed. Sharing a quilt with my wife is not a pleasant experience, as the only heating benefit gained is friction burns caused by the quilt flying past in her direction, as she wraps it round herself at about 15rpm.

We had this conversation... :o)

Because the bed in the spare bedroom is too small.

Reply to
Huge

OK, I'll try one of those, instead.

BTW, for all the electric blanket fans, SWMBO has vetoed that. She wants the air temperature raised to acceptable levels.

Reply to
Huge

Ooh. Tinkering to be done. Thanks!

Reply to
Huge

A solution for tonight - get inside it and connect the 2 x 1Kw elements in series to make a 500 w one which is probably nearer the actual output you need during the night and turn the thermostat up to max. You could re-jig the switchery to give a choice of 1 kw or 500w so you can preheat the room before you retire.

If it's cycling with the frequency you describe ISTM the heater is badly designed anyway. The thermostat is getting ackled directly by the heating element itself rather than the air temperature of the room. It would benefit from being divorced from the heater itself. To that extent a 14 quid plug in thermostat would give you less grief because of less cycling and even if it had a relay in it the absence of the resonant tin box must make it quieter.

DG

Reply to
derek

Presumably as its only your head that will benefit, have you thought about buying a couple of balaclavas?

.... you could always add goggles afterwards if she still complains about her eyelids getting cold.

Dave

Reply to
Dave Gibson

*LAUGH*

Can you come round and explain this, please? I fear for my life if I try.

Reply to
Huge

;-) There must be a joke in there somewhere, women, entropy, natural order of the universe, that sort of thing.

You could still try an underblanket. They lend themselves well to "sidedness".

What about the spare wife - is she no better ?

Reply to
John Laird

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