# the Truma combi boiler



## gillnpaul (Jan 6, 2007)

Hi Guy's
Just an enquirey that those with a Trauma Combi 4E/6E can answer, I'm struggling a bit.
We have just bought a sqeaky new A/T Dakota with one of these Trauma' s fitted. It has two control dials above the door.
Firstly am I correct in thinking that the r/h side dial with 1-5 in for the room temp?.
Secondly that the combi can only be run (water heating and room heating) can only be run on gas AND electricity not just electricity alone if this is the case, how much gas does this use...a better way of asking is this question is which is the main fuel gas or electricity.

If we are using the van in mid winter, so want maximum heat and hot water, what settings do I need to use.
I can't get my head around why I need to use both fuels not just EHU.
If on EHU then why should I need to use my gas as well?

Thanks for the help
Paul


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## geraldandannie (Jun 4, 2006)

Hi Paul

I think you've got the same as us. Firstly, yes, the numbered dial is the 'stat. The outer ring controls whether you want heating, hot water, hotter water, or heating and hot water.

The dial underneath allows you to select gas only, electric (low power) only, electric (high power) only, or gas and electric.

Didn't you get a Truma manual with the van? It comes with a single sheet idiots' guide (I needed it).

Gerald


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## rayc (Jun 3, 2008)

http://www.truma.com/downloadcenter/combi46_kurzanleitung_de_gb_fr_it.pdf

http://www.truma.com/downloadcenter/combi46_instruction_de_nl_fr_it_gb_dk_e.pdf

quote: "If we are using the van in mid winter, so want maximum heat and hot water, what settings do I need to use. 
I can't get my head around why I need to use both fuels not just EHU. 
If on EHU then why should I need to use my gas as well? "

Firstly you do not need gas and electric at the same time but you can if you want a quick warm up. Gas will warm the boiler up quicker than electric only.
If you want maximum heat and hot water then what I do on my boiler is set the thermostat setting to maximum and select whatever power source I want e.g. electric only / gas only or electric+ gas. I then set the control for Heating only. This starts to heat the living space up without waiting for the water to get up to temperature first and even on electric only it only takes 30 minutes or so to raise the temperature by 15 degrees or so. The water gets hot in any event.


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## DJP (May 9, 2005)

Hi Paul
Do you have a fire in the van or is it just warm air heating?
Whichever it is, both units can be run on gas or electric or both. The output on electric is about 1kw or 1.8 kw. The output on gas is about 3.2kw so with both on it is about 6kw of heat output. 
tThe 2 knobs over the door. One of them determines the power supply, gas or electric, the second one is different if it is warm air or if you have a fire. Assuming it is a fire then on EHU leave the left knob a 3pm position and turn the right one one click. That heats the water to 40 or 2 clicks to 60. The the rotary dial in the centre is the thermostat for the heating via the fire.
If it has warm/blown air heating there is an excellent post here <MHF Truma Control instructions
Hope that helps.


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## Bill_OR (Feb 6, 2010)

Paul,
Our Combi will heat the water and/or the motorhome on gas or mains electricity. The water heating works efficiently whichever fuel is used (although it's faster with gas) but the space heating is much better on gas then electricity.

I have the instruction booklet but it doesn't really explain the dual fuel setting - but my impression is that it heats the water using mains electricity and the space heating by gas.
Bill


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## gillnpaul (Jan 6, 2007)

*The Combi*

Thanks for your replies
Gerald, this looks really bad cus I can't understand the idiots guide LOL.
What I cant get to grips with, is why when on EHU, do you have to use gas as well? It doesnt make sense, So if you run out of gas, you cant have your heating on, sorry for my stupidity! (It's my age)

Hi DJP, no there's no fire (although we do have a stand alone fan heater, which in Leeds last weekend was a godsend, but switched it off during the night and awoke cold and fed up. I think it was because I had it on , what I thought was electricity only, this seems to be the 'summer' setting ....water heater only. I don't think that I can run it on electricity only DJP.
Thanks rayc, Ive got the manuals, Its just that I cant interpret them or belive what I'm reading.

regards

Paul


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## DJP (May 9, 2005)

Hi Paul
You can definitely run it on EHU only. Although at 1.8kw max heat out put it is not that effective if temperature drops below about 10.

This post does explain it very well

http://www.motorhomefacts.com/ftopict-38161-truma.html


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## rayc (Jun 3, 2008)

*Re: The Combi*



gillnpaul said:


> Thanks for your replies
> What I cant get to grips with, is why when on EHU, do you have to use gas as well?
> Paul


No you select which ever fuel source you want i.e. electric only, gas only or gas + electric. The only reason to select gas + electric is for a fast warm up. Gas will heat the boiler up quicker than electric and gas + electric will heat it even quicker. If you decide to use gas + electric to give fast warm up you can switch to electric only when it is warmed up

The water boiler and the space heating are dual power source so will work on electric, gas or both.

Note that you cannot heat water, i.e.the boiler, by gas and space heating by electric or vice versa. The power source you select will power both the heater and boiler.

In my experience the Combi 6 is superior to the Combi 4 as far as EHU only heating at low temperature as you would expect. If the MH manufacturer has been stingy and put a Combi 4 in a large MH then it could struggle at low temps with electric only.


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## DJP (May 9, 2005)

> Note that you cannot heat water, the boiler by gas and space heating by electric or vice versa. The power source you select will power both the heater and boiler.


But you can have the heating on EHU without water in the tank.


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## rayc (Jun 3, 2008)

DJP said:


> > Note that you cannot heat water, the boiler by gas and space heating by electric or vice versa. The power source you select will power both the heater and boiler.
> 
> 
> But you can have the heating on EHU without water in the tank.


As you can with gas or even gas+electric


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## Caggsie (Aug 19, 2008)

I use ours on combined fuel for a quick boost to warm up quickly. Very effective. We tend to use a small oil filled radiator for back ground heat during the night. Although not effective in keeping the van toasty keeps the main chills away and find the vans own heating too effective overnight, which seems to kick in about 3am, with a duvet on and find nose etc has dried up.


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## geraldandannie (Jun 4, 2006)

*Re: The Combi*



gillnpaul said:


> What I cant get to grips with, is why when on EHU, do you have to use gas as well? It doesnt make sense


Indeed it doesn't, which is why it's not true. Where did you get the idea from that you need to use both? You *can* use both, but you don't *need* to use both.

When we were away recently, on the 2 nights we had hookup, we left the heating on a low level all night on electric only. Lovely and toasty in the morning!

Gerald


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