# Electric heating not understood



## SandraF (Oct 24, 2010)

Previously caravanners, we have bought our first motorhome, a Swift Sundance, but are confused by the controls on the electric heating, partly because they don’t match the pictures in the documents that came with the motorhome (it’s secondhand, from a dealer, whose technical advice left something to be desired!). The heating incidentally is a Truma convector type unit, with two ducted warm air outlets.

The wall controller seems to be straightforward – choice of 500, 1000 or 2000 watts heating, and a thermostat.

The controller on the heater unit itself has a dial, which is presumably another form of thermostat, and a moveable switch. To the right it sets the fan off, but it doesn’t turn off when the thermostat cuts out, and therefore blows out cold air. 

The middle `filled in’ O seems to be for operating it as just a convector heater.

To the right it is marked `A’, but haven’t yet worked out what this is about.

So that’s the controls which no doubt many will recognise. But apart from doubts I have listed above, my main concerns are firstly, what is the relationship between the two different controllers? Does one override the other? – or what?

Secondly, during a try-out in Cumbria a few days last week (think 100mm rain between Tuesday and Thursday – not one of my better ideas!) – it seemed that a thermostat was cutting out once the home was comfortably warm, but not cutting back in until it had become decidedly chilly. My wife thinks this is unacceptable, and thoughts of a freestanding low wattage fan heater came to mind.

But that can’t be the right answer; I must be doing something wrong. Our last caravan also had ducted warm air, but the wall controller was one unit where a button enabled you to select the type of heating thanks to a vertical strip where you moved the light up and down, and a circular thermostat – I’m sure some people will recognise what I am describing. But this worked perfectly well.

Advice very welcome please.

Barry Fisher


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## philoaks (Sep 2, 2008)

From memory (as my current van is a bit different to yours) the switch on the actual heater is for the blown air. In the centre position it works as a convector heater. To the left it gives you blown air heating whilst running on gas and to the right it gives you blown air whilst running on mains electricity.

The second switch on the wall controls the heater whilst running on mains electricity so you can choose the level of heating firstly by choosing the wattage in use and then by setting the thermostat by rotating the dial.

Whilst running on gas this wall switch will have no effect and the temperature is controlled by the rotary switch on the heater.

I stand to be corrected as my memory ain't what it used to be!


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## SandraF (Oct 24, 2010)

Not sure about the gas, because I deliberately did not show the gas controls as I had not used them. There is a Truma Ultrastore thermostat (which I believe is gas) next to the wall mounted electric heating thermostat which I did show. And on the convector unit the gas controls (again, not shown) are on the right of the unit.

You may be right, I just thought there were two sets of controls, one for electric heating and one for gas, and had guessed that the two were independent.

Anyway, something for me to check out on my next visit. 

Thanks for taking the trouble to reply,

Barry Fisher


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## waggers (Oct 2, 2010)

my understanding is that the A is for auto and will therefore work on the thermostat

the curved wedge shape is a manual setting for the fan so, as you say will blow out regardless of the tempreture of the air being bumped.


they work the same regardless of if you are using gas or electric as these are fan controls only.


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## philoaks (Sep 2, 2008)

waggers said:


> my understanding is that the A is for auto and will therefore work on the thermostat
> 
> the curved wedge shape is a manual setting for the fan so, as you say will blow out regardless of the tempreture of the air being bumped.
> 
> they work the same regardless of if you are using gas or electric as these are fan controls only.


I said my memory was going. I'm sure waggers is right as I remember now being able to put the fan on in warm weather to move the air around so that must have been what the left switch position does.

The ultrastore controls will be for the water heater side of things I think (subject to my memory again!)

Edit. Yes it's all coming back to me now. The switch in you pic controls the fan on/off/auto and the numbers control the speed of it. The fan is totally independent of the heat source as waggers says and will blow the air around whether on gas/electric or nothing.


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## GerryD (Sep 20, 2007)

The position marked A is for automatic fan speed adjustment. What this does it to vary the fan speed according to the temperature of the air being delivered from the heater. When the thermostat has allowed the heater to cool down then the fan speed shuts down to its lowest possible speed. When the heat is on full then the fan speeds up to the speed set on the dial (1 to 5). The position at the other end provides a constant fan speed according to the speed dial.
Hope this helps.
Gerry


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## Frantone (Sep 6, 2006)

*Ultraheat control*

I have experienced this effect myself i.e. the thermostat being apparently slow to react to lower temps. This may be due to the siting of the control which has the thermostat built in. If it is near another source of warmth (maybe you or a light fitting) it does not register ambient temp of the habitation space accurately. The possible answer is that there is a remote temperature sensor for the Truma which is an easy DIY fit so that it can be sited further away.
TonyP


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## SandraF (Oct 24, 2010)

Tony,

You may be on to something - there is a spotlight within 9 to 12 inches of the thermostat. Will check this out - thanks!

Barry


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## wakk44 (Jun 15, 2006)

I have the same heating system in our Autotrail,the slider control is for the blown air heating fan,centre position fan is off,to the right(A)is automatic and will alter the fan speed according to what the small dial has been set to

Slider to the left is manual speed setting for the fan and can be adjusted by the small dial next to the slider(1-5).

I too find the electric setting a bit imprecise and reluctant to switch back on with the thermostat allowing the van to get cold.

In my experience with this system I have found the best and most accurate setting to be on gas around about no.5 and the slider switch set to manual on about no.2,and then just control the temperature with the large gas control dial,in that mode it is a powerful and efficient heating system. :wink:


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## SandraF (Oct 24, 2010)

Steve,

Thanks - I think I am getting to grips with the electric side of it now, and will investigate the use of gas soon, having noted the settings you suggest.

Barry


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## TR5 (Jun 6, 2007)

Most mechanical thermostats are not very accurate with regard to the differential - i.e. the difference between the cut off and cut on points, and this can often be too large.

If there is an option (and I do not know with your heating) to fit a digital thermostat, this will help.

Only other solution I can suggest is, when near the temperature you find comfortable, turn the heater output down, and switch the fan to a constant low speed, to maintain the temp.


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## SandraF (Oct 24, 2010)

Michael,

Thanks for you suggestion - working backwards, I have yet to find a heating temperature my wife is comfortable with!

The digital thermostat idea may be feasible for the motorhome, but it may also help at home because since the new heating system was install a few years ago, I have always felt the temperature differential too great on it. Maybe the Honeywell thermostat they used was from the cheaper end of those available.

Barry


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## kandsservices (Sep 5, 2010)

You can get a remote sensor for the heater from www.miriad-products.co.uk this eliminates your thermostat problem as you can install this sensor away from any heat source they just plug in to the unit so its easy to fit,hope this helps.

Kev kands services for all your caravan and motorhome needs


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## Rudderman (May 31, 2005)

Barry

I have a Sundance and the same heater as you.

You have already got (from above) all the help you need, except to
say that the fan is 12volts only and so no hookup required except you will have to use gas to heat.

We find that we don't need the fan on much, except to blow air into the bathroom when required!!!!!!!

We had a remote thermostat sensor fitted on our system which was much better.

Hope this helps


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## BazzaF (Nov 7, 2010)

Kev,

Thanks - I will follow this up.

Barry


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## BazzaF (Nov 7, 2010)

Bob from sunny Devon!,

Sorry for delay in responding, but there is confusion all round as unknown to me, my wife had registered, whilst I subscribed, using the same e-mail address, which has upset the computer (so am using an obsolete e-mail address we had).

But - thanks for e-mail, I will be following this up. Is it possible to give me a brief outline of how you did this and whereabouts you had the remote sensor fitted?

Which will be useful, always assuming I can get back into this forum!

Thanks, 

Barry (from chilly Wolverhampton)


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## Rudderman (May 31, 2005)

Barry

West Country Motorhomes fitted the sensor, free, after having complained to them about the heating keeping on cutting out. I had just purchased the motorhome from them. (2003)

The sensor is fitted in the back of the locker,near the wheel arch, under the seat below the thermostat control. This worked a lot better as the locker is cooler than the rest of the van.

Hope this makes sense.

Regards,

Bob from windy north Devon!!!!!


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## SandraF (Oct 24, 2010)

Just a quick thanks to those who ofered help on this subject - belated due to forum subscription problems.

I have ordered the suggested remote sensor, and with the greater understanding of how the heating unit works, hopefully the blowing cold problem will be resolved.

Thanks,

Barry Fisher


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