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Not so, the hot water system is heated by the same heating element / burner as the heating, you cannot heart the caravan without heating the hot water, that said when both are running if the central heating is calling for heat the hot water is also being heated without temperature control. It can result in very hot water coming out of the tap, not so much a problem for adults but may be an issue if children are around.

The hot water temperature is governed. It cannot become hotter than the circulated heating water which is itself governed.

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Not so, the hot water system is heated by the same heating element / burner as the heating, you cannot heart the caravan without heating the hot water, that said when both are running if the central heating is calling for heat the hot water is also being heated without temperature control. It can result in very hot water coming out of the tap, not so much a problem for adults but may be an issue if children are around.

Surely only dangerously hot if the mixer is turned up too high ?

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Once again you are completely wrong. ..!

 

I think you have either misread or misunderstood my last post. 50 degrees is the default fixed temperature of the Alde boiler's hot water system. The temperature can, if required be raised by the user up to 65 degrees. The purpose of the boost is to permit an extended shower time up to a maximum of 30 minutes.

 

The actual temperature of the water issuing from the shower head is set independently of the boiler system irrespective of the manufacturer.

As with all caravans and motorhomes the temperature of the water coming out of the shower head can be adjusted by the user by using the mixer tap. The temperature range then is infinitely variable from cold to a maximum of 50 degrees.

 

The temperature of the water for showering can easily be set to the ideal of 35 to 40 degrees which is considered as the standard safe temperature range for a human being to take a shower.

 

No right minded person would shower in pure hot water only, unless they wanted 3rd degree burns. Water in your home’s domestic hot water system is pre-set to 60 degrees. ;)

So are you really saying that 50 deg C is the maximum temp of the water going round to heat the van? If that's the case I am indeed wrong

 

I do however feel that 50 deg C would be too low for the heating side of the system.

The hot water temperature is governed. It cannot become hotter than the circulated heating water which is itself governed.

Yes agreed but what is the temp of the fluid going round the rads?

Surely only dangerously hot if the mixer is turned up too high ?

Yes correct, not sure about your shower tap but mine needs very fine control to get the temp right, it would be very easy for child to get it too hot.

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Not so, the hot water system is heated by the same heating element / burner as the heating, you cannot heart the caravan without heating the hot water, that said when both are running if the central heating is calling for heat the hot water is also being heated without temperature control. It can result in very hot water coming out of the tap, not so much a problem for adults but may be an issue if children are around.

 

Sorry squire - just look on page 2 of the pdf in the link below and you can see that there are 2 separate heating systems with 2 separate fluid jackets AND if you look at their FAQ Alde are quite clear that you can run the central heating and have the hot water system empty.

I can also state that unless mine aint working properly, the hot water doesn't get any hotter when the central heating is on.

 

http://www. alde. co. uk/downloads/alde_3010_instruct. pdf

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So are you really saying that 50 deg C is the maximum temp of the water going round to heat the van? If that's the case I am indeed wrong

No he's wrong. You only need to download and read the manual for the Alde system to realise that. On CH the HW in the jacket around the CH water jacket will eventually reach the temp of the CH liquid being circulated. It is inevitable.

 

Note: 50C water temperature is (just) too low to kill legionella so one should use boost occasionally in the summer (although iirc Alde's system may do that automatically from time to time?) to get it higher (60C is the recommended storage temp for HW).

 

The latest water regs/building regs require that all hot taps to baths are limited to prevent scalds (48C). Most often this will be via thermostatic mixers. Caravans don't (yet) have such features. Nor, however do most homes. NB it is for baths only as (I guess) most people will jump out of the way in a shower or turn it off if it is too hot (or cold) and that few incidents of severe scalding due to showers have been reported cf baths?

If anyone is especially concerned for their child's safety then a retro-fit change to a thermostatic shower control should be considered.

Edited by Rodders53

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I thought that the system ran at 60 degrees and that a short term boost to 65 was available. I seem to remember the engineer at Alde (earlier this year) saying the boiler is up to temperature (and reading 58 degrees on the control panel at the time). I assumed that he meant it was more or less up to 60 at that stage.

 

You can run it without water in the hot water tank - not sure why you would want to though?

Edited by Easy T

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[snip] I suspect you are labouring under a slight misapprehension about the 500w/1000w/2000w setting thing. If I am understanding it correctly, that setting does not control heat output of the convector, but rather limits the amount that it might try to draw from the EHU outside. So you would only need to set it on 500w if you had a low (say 6amp) supply on the peg outside. The amount of heat that the convector actually puts into your caravan is normally set on the thermostat which in our case is a dial numbered 0-9 by the door.

Mike

Not sure I understand this. Why would the manufacturer go to the trouble and additional cost of adding a 500w/1Kw/2Kw selection facility if the 500w setting delivers exactly the same as the other two. A single 500w setting would do the job.

 

I suspect that the lower settings would take rather longer to reach any given temperature set on the thermostat than the higher settings would take.

 

 

 

You should also consider that with the alde you have no control over the hot water temperature and when it is heating the hot water it will have affect on the heating performance ( probably not significant)

My last van had the separate Truma Ultraheat (fire/blown air) and Truma hot water boiler. Heating the water with gas provided temperature control via a rotary selector but heating with electricity gave no control whatsoever other than the on / off switch.

 

http://www. alde. co. uk/faq. php

Q: Can I operate my central heating while the fresh water is drained down?

A: Yes, you can operate the system as normal, even with fresh water drained down.

 

Seems to suggest that the two subsystems are separate.

 

We always want hot water (and just turn the heating right down to lower than ambient) so have not yet had need to experiment with the Alde.

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Not sure I understand this. Why would the manufacturer go to the trouble and additional cost of adding a 500w/1Kw/2Kw selection facility if the 500w setting delivers exactly the same as the other two. A single 500w setting would do the job.

 

I suspect that the lower settings would take rather longer to reach any given temperature set on the thermostat than the higher settings would take.

 

 

 

My last van had the separate Truma Ultraheat (fire/blown air) and Truma hot water boiler. Heating the water with gas provided temperature control via a rotary selector but heating with electricity gave no control whatsoever other than the on / off switch.

 

 

Seems to suggest that the two subsystems are separate.

 

We always want hot water (and just turn the heating right down to lower than ambient) so have not yet had need to experiment with the Alde.

 

500, 100, 2000 allows you to use the heat on a supply limited to less then 16amp.

 

The gas is an entire separately controlled system to the electric systems, in both hot water and heating systems - basically two completely separate heaters in the one box. You can if you wish use both simultaneously, the heater rating increases to 5Kw

and the water heater to around 2. 5Kw I think.

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Not so, the hot water system is heated by the same heating element / burner as the heating, you cannot heart the caravan without heating the hot water, that said when both are running if the central heating is calling for heat the hot water is also being heated without temperature control. It can result in very hot water coming out of the tap, not so much a problem for adults but may be an issue if children are around.

 

So are you really saying that 50 deg C is the maximum temp of the water going round to heat the van? If that's the case I am indeed wrong

 

I do however feel that 50 deg C would be too low for the heating side of the system.

 

What is the temp of the fluid going round the rads?

 

 

Oh dear, you still have it wrong. I will try to make it clear for those that still don’t understand it. :rolleyes:

 

The hot water system in the Alde boiler is independent of the Central heating cylinder.

The boiler consists of three eccentrically fitted cylinders;

  1. Heat exchanger,
  2. Water jacket for the heating system
  3. The outermost is the water jacket for the hot water.

The heat exchanger is divided into two semi-circles. The burner is located in the upper half, being the combustion chamber, and the combustion gases are expelled through the lower half.

 

The burner unit is fitted on the end of the heat exchanger. It consists of a combustion fan, burner, solenoid valve and intake/exhaust connections. Two heating cartridges are fitted to the water jacket of the heating system.

 

The temperature of the central heating water is maintained at 80 degrees; however the hot water side cannot reach that temperature, because it is independent. Yes there is heat transfer, but only enough to warm the water in the hot water side of the boiler that is present at the taps and shower.

 

In fact it is another benefit of the Alde system. If the user only requires warm water at the taps and shower head, then when running the central heating side of the boiler the hot water side can be left set to off. By so doing there will only be warm water available from the taps and shower head. ;)

 

It doesn’t matter which way you cut it the Alde wet system is way ahead of anything else. It is the reason why any future caravan or motorhome I purchase, would have to be equipped with the Alde wet system, for me to even consider it. :)

 

In motorhomes another bonus with the Alde system is the habitation area's central heating system can be heated from the engine of the motorhome, thereby arriving at your destination with a comfortably warm habitation area. :D

Edited by WindlePoones

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500, 100, 2000 allows you to use the heat on a supply limited to less then 16amp.

 

The gas is an entire separately controlled system to the electric systems, in both hot water and heating systems - basically two completely separate heaters in the one box. You can if you wish use both simultaneously, the heater rating increases to 5Kw

and the water heater to around 2. 5Kw I think.

Thanks Harry but you seem to have answered questions yet to be asked. .. icon_confused.gif

 

Re: Answer 1.

I understand that bit. ... the comment to which I was responding was that these settings made no difference to the actual output of the heating system. (same output, thermostat to control actual space heating)

 

What I said was along the lines of - "if that was the case then only the 500w setting would be needed for all flavours of EHU so why would caravan builders provide the selector switch etc.

 

Answer 2. I also understand that gas and electric water heating have two control systems. I was commenting on the remark that the Alde system provides no control over the hot water temperature. The Truma to which I referred also gives no user temperature control when operating on electric. (It does if operating on gas).

 

I concluded by suggesting that the perhaps the Alde subsystems could be operated independently of each other but that I haven't ever needed to try it out.

 

Perhaps the context of my comments wasn't as clear as it might have been.

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Oh dear, you still have it wrong. I will try to make it clear for those that still don’t understand it. :rolleyes:

 

See here for a cutaway view of the Alde construction http://www. alde. co. uk/alde-compact-products. php?itemCat=alde%203010%20compact%20system Nothing in that will significantly slow down the heat transfer into the Hot Water cylinder from the CH glycol/water mix - whether electrically or gas heated. Note Alde state >50C and >65C i. e. the water will always be hotter than the figures. Only if CH is off will the water temperature be controlled. The laws of heat transfer physics cannot be denied.

 

Now in practical use in the UK especially you may find that CH is cycling on and off and maintains the HW at around the 60 mark as a result . .. but in colder climes this could well be exceeded. Indeed the CH liquid may never need to get as hot as 60C to warm the caravan on many days in the UK??

Edited by Rodders53

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Thanks Harry but you seem to have answered questions yet to be asked. .. icon_confused.gif

 

Re: Answer 1.

I understand that bit. ... the comment to which I was responding was that these settings made no difference to the actual output of the heating system. (same output, thermostat to control actual space heating)

 

What I said was along the lines of - "if that was the case then only the 500w setting would be needed for all flavours of EHU so why would caravan builders provide the selector switch etc.

 

Quite simply, if you have a 16amp supply available, then you can use the 2000w setting to warm things up faster and the system would be better able to cope with really cold conditions, without need to resort to gas to supplement it. You also have the option to run the heating on a lower setting, should you need to run say a microwave. If you are limited to 6amp and the weather is cold, then you have little choice but to supplement the electric heat with gas.

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See here for a cutaway view of the Alde construction http://www. alde. co. uk/alde-compact-products. php?itemCat=alde%203010%20compact%20system Nothing in that will significantly slow down the heat transfer into the Hot Water cylinder from the CH glycol/water mix - whether electrically or gas heated. Note Alde state >50C and >65C i. e. the water will always be hotter than the figures. Only if CH is off will the water temperature be controlled. The laws of heat transfer physics cannot be denied.

 

Now in practical use in the UK especially you may find that CH is cycling on and off and maintains the HW at around the 60 mark as a result . .. but in colder climes this could well be exceeded. Indeed the CH liquid may never need to get as hot as 60C to warm the caravan on many days in the UK??

 

Rodders, I don’t really understand your point. It works perfectly well. There is no scalding water at the taps. I have already explained how it is avoided and how there is only a partial heat transfer from the CH side to the HW side.

 

Perhaps you will understand when you have used a caravan that has an Alde system; it knocks the Truma system into a cocked hat.

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Rodders, I don’t really understand your point. It works perfectly well. There is no scalding water at the taps. I have already explained how it is avoided and how there is only a partial heat transfer from the CH side to the HW side.

 

Perhaps you will understand when you have used a caravan that has an Alde system; it knocks the Truma system into a cocked hat.

I'm not saying the Alde is poor at all. I wouldn't wish to disrespect it at all. I wish I had it in many ways. But I cannot see how Alde system can regulate the temperature of the hot water jacket that surrounds the central heating water jacket from the diagram. You just claim the two are independent but I cannot see how a tank of water surrounding another thank of water which is heated up by electric elements inside it or by a burner in its centre, can be heated independently of the middle cylinder. If it were a separate tank heated as per in a house then OK but this is not. Everything I've read elsewhere says the HW warms by conduction from the CH cylinder so if that can get to 85C (max Alde state) then the HW must eventually rise to nearly that temperature, given long enough.

 

However, do me a favour and perform a little experiment:

 

1. Get an accurate water thermometer.

2. Run your Alde hot water and ascertain the max temp. as you have it as you run the system normally

3 THEN go out for the day when next on site, but with the Alde CH on MAX temp and 3kW with all the windows and vents open a bit to lose the cabin heat as fast as you can i. e. with the CH boiler going continuously for 3 or 4 hours. {Or do this at home with the windows wide open}

4. Then repeat the hot water temperature check. {Every 30 mins if staying with the 'van during the test.}

5 Report back the results.

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Sorry squire - just look on page 2 of the pdf in the link below and you can see that there are 2 separate heating systems with 2 separate fluid jackets AND if you look at their FAQ Alde are quite clear that you can run the central heating and have the hot water system empty.

I can also state that unless mine aint working properly, the hot water doesn't get any hotter when the central heating is on.

 

http://www. alde. co. uk/downloads/alde_3010_instruct. pdf

Apology accepted 'squire' have another read at what I said. I acknowledge there are 2 jackets the central heating one on the inside but what I did say was that it's impossible to have the heating on without heating the hot water, that said, whilst the van is calling for heat the hot water is also getting hotter i. e. NOT independently controlled.

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The temperature of the central heating water is maintained at 80 degrees; however the hot water side cannot reach that temperature, because it is independent. Yes there is heat transfer, but only enough to warm the water in the hot water side of the boiler that is present at the taps and shower.

. :D

 

Hehe, oh dear Iit seems I got it right. I'm fully aware of the water jackets and burner setup, I can't wait for the explanation of how the water knows to stop absorbing heat at 50 degs despite been surrounded by water at 80. If left long enough and if the weather is cold enough the boiler is going to keep that water at 80 and the hot water will follow.

 

 

Perhaps you will understand when you have used a caravan that has an Alde system; it knocks the Truma system into a cocked hat.

 

But seemingly from many threads, it's heavier, slower and doesn't heat the bathroom, so perhaps not quite so cut and dry?

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Quite simply, if you have a 16amp supply available, then you can use the 2000w setting to warm things up faster and the system would be better able to cope with really cold conditions, without need to resort to gas to supplement it. You also have the option to run the heating on a lower setting, should you need to run say a microwave. If you are limited to 6amp and the weather is cold, then you have little choice but to supplement the electric heat with gas.

Yes - that's my understanding too. the 500/1000/2000 switch is not a thermostat. If you have a thermostat relating to the electric heating it is likely on the wall near the door and will attempt to reach the temp you have set (usually graded 0-9) no matter what you have set the 500/1000/2000 switch to. As Harry says - if on the 500 setting it won't do it as quickly as if it were on 1000 or 2000 but you can only use the higher settings if your campsite is delivering you enough amps.

Mike

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I note that this thread, like so many before it, has become over technical & a point-scoring exercise on the part of some.

 

Having had most of the older systems & experienced the latest (noisy!) warm air type, & now having Alde (for 3 seasons) I know which I prefer, this despite the extra weight & very remote potential for water leaks (though nowhere near that of the standard water system!).

 

The choice is quite simple IMHO:

a, if mostly CL camping during the warmer seasons with no EHU, & for more than w/e's, the basic warm air is less problematical (except the latest under floor warm air which still hammers the battery) & much cheaper.

b, for longer periods & all year round camping with EHU during the colder season (which is cheaper than using gas anyway) then the Alde system is unbeatable.

It's quite & efficient & it wont keep you awake at nights. It does seem to take up to an hour to initialy warm a cold 'van, but this is ALL the 'van not just the bits in front of the vents, & there are definitely less draughts for whatever reason. Granted the bathroom (with the door closed) is not heated to the same extent, & I'm not sure I would want it to be as I don't live in there, either when in the 'van or at home, perhaps some people do. ......

 

There seems to be a separate dispute regarding scalding potential. Surly this applies no matter where & requires a modicum of common sense to avoid it?

 

Yer pays yer money & yer takes yer choice, horses for courses, don’t knock it until you've tried it, etc. etc

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I'm not saying the Alde is poor at all. I wouldn't wish to disrespect it at all. I wish I had it in many ways. But I cannot see how Alde system can regulate the temperature of the hot water jacket that surrounds the central heating water jacket from the diagram. You just claim the two are independent but I cannot see how a tank of water surrounding another thank of water which is heated up by electric elements inside it or by a burner in its centre, can be heated independently of the middle cylinder. If it were a separate tank heated as per in a house then OK but this is not. Everything I've read elsewhere says the HW warms by conduction from the CH cylinder so if that can get to 85C (max Alde state) then the HW must eventually rise to nearly that temperature, given long enough.

 

However, do me a favour and perform a little experiment:

 

1. Get an accurate water thermometer.

2. Run your Alde hot water and ascertain the max temp. as you have it as you run the system normally

3 THEN go out for the day when next on site, but with the Alde CH on MAX temp and 3kW with all the windows and vents open a bit to lose the cabin heat as fast as you can i. e. with the CH boiler going continuously for 3 or 4 hours. {Or do this at home with the windows wide open}

4. Then repeat the hot water temperature check. {Every 30 mins if staying with the 'van during the test.}

5 Report back the results.

 

Hi Rodders,

 

I would like to oblige you, but I don’t go caravanning all year round. My caravan is already winterised and it is now sitting on my driveway with its Protec cover on.

I suppose I could carry out those tests in the spring, but clearly there is a degree of thermal separation in the water cylinders/jackets, else as you say it is probable that both could reach the same temperature. When in reality the water in the HW side only gets hand warm, when only the central heating is on and the hot water off.

 

The other thing to consider is the flow side of the CH is at around 80 degrees as it enters the radiators, but after being pumped around all the radiators in the caravan the return is at a much lower temperature.

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I note that this thread, like so many before it, has become over technical & a point-scoring exercise on the part of some.

 

Having had most of the older systems & experienced the latest (noisy!) warm air type, & now having Alde (for 3 seasons) I know which I prefer, this despite the extra weight & very remote potential for water leaks (though nowhere near that of the standard water system!).

 

The choice is quite simple IMHO:

a, if mostly CL camping during the warmer seasons with no EHU, & for more than w/e's, the basic warm air is less problematical (except the latest under floor warm air which still hammers the battery) & much cheaper.

b, for longer periods & all year round camping with EHU during the colder season (which is cheaper than using gas anyway) then the Alde system is unbeatable.

It's quite & efficient & it wont keep you awake at nights. It does seem to take up to an hour to initialy warm a cold 'van, but this is ALL the 'van not just the bits in front of the vents, & there are definitely less draughts for whatever reason. Granted the bathroom (with the door closed) is not heated to the same extent, & I'm not sure I would want it to be as I don't live in there, either when in the 'van or at home, perhaps some people do. ......

 

There seems to be a separate dispute regarding scalding potential. Surly this applies no matter where & requires a modicum of common sense to avoid it?

 

Yer pays yer money & yer takes yer choice, horses for courses, dont knock it until you've tried it, etc. etc

hi I will second this I think most of the poster's have not experienced the heating systems that They are commenting on. As to the bathrooms being cooler than rest of van that is one make only. Cutting corners to save money. My van's bathroom has a radiator so is warm.

Terry.

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Hi all, I started this off as a general interest. CTS 50 did say I was opening a can of worms. But to sum up most who have wet systems love them and would not go back. Others like me go for blown air and happy and a few (definitely me) miss blown air with a silent radiator. What was wrong with that!

 

Thanks to everyone who contributed to this one.

 

Paul

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Hi paul my last van had fire plus blown air. I posted about insulating the 2. 5 mts which went outside. I also installed electric under floor heating but with such a big van that I had we never felt warm. The thermostat would never keep the heat at a steady temperature. Now changed to alde noticed the difference, will never go back to blown air.

Terry.

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Hi paul my last van had fire plus blown air. I posted about insulating the 2. 5 mts which went outside. I also installed electric under floor heating but with such a big van that I had we never felt warm. The thermostat would never keep the heat at a steady temperature. Now changed to alde noticed the difference, will never go back to blown air.

Terry.

The inability to hold a set temperature, with wide swings, was long ago identified as an issue with installation. Basically the sensor was installed too close to the heat source. Mine has a properly positioned sensor and maintains a very stable temperature, once it has settled. A badly positioned sensor can affect any heating system, including the Alde.

 

Temperature attainable is a matter of heat input versus heat loss. 2kw of heat from a blown air system, given similar losses, should produces an identical to temperature to 2Kw of heat from an Aldi system. I suspect despite your suggestion that you insulated the 2. 5m of duct, that it still lost a considerable amount of the 2Kw. Mine had an uninsulated duct 3m long, it was not absolutely essential, so rather than attempt to insulate it, I simply did away with it. The difference in cold weather was nothing less than the difference between night and day. Rapid heat up, and holding the temperature easily on even the coldest of days.

 

It is unfair to blame the technology, when the installation is at fault.

Edited by harry.m1byt

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The inability to hold a set temperature, with wide swings, was long ago identified as an issue with installation. Basically the sensor was installed too close to the heat source. Mine has a properly positioned sensor and maintains a very stable temperature, once it has settled. A badly positioned sensor can affect any heating system, including the Alde.

yes I had moved my sensor too. I found the thermostat had two wider gap between on and off.

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yes I had moved my sensor too. I found the thermostat had two wider gap between on and off.

 

Which could also be due to poor sensor positioning.

 

Mine was already fitted with the recommended remote temperature sensor, fitted adjacent to the door. I removed the duct completely which had originally fed the rear bathroom, due to tremendous heat loss form its 3m long duct. Instead I added an outlet 1 foot from the sensor, but still by the same door. I fully expected it would upset the sensor, but I found it worked absolutely fine. The gap on the stat dial remains as one full digit, there has to be some hysteresis between the on and off positions on any heating system, unless it has some means of modulating its output.

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