New Truma Combi 4E : Problems

[Rayjsj]

Hi All,

We are away in very chilly Norfolk testing out our new motorhome, a few little things easily fixed, but the most serious is the Truma Combi seeming to have a 'mind of it's own'. IE. setting 3 with full 1800 w electric and gas produces a very poor heating in the van (although the 'interior' temperature gauge registers 25c. which it isn't. Tested by a good old mercury level pocket gauge !! The electronic one is overreading by at least 6c. ) So, turn control upto 4 , as by now it's very cold in van, Fans whoosh masses of heat bursts forth, check interior electronic gauge, now reads 22c and DROPPING although my mercury gauge is reading 28c-29c ! if left on 4 or 5 heat just keeps coming and coming until it trips out with a red 'fault' LED, which resets after being off for 10 mins or so.

My thoughts: The room sensor FF2 is 'kaput' or wrongly wired up ?

This is a 2012 Van, probably built late 2011, with Euro 5 engine, surely it will have all the latest 'upgraded PCB's' in the fan controllers (read about problems in 2010 on another forum).

Any thoughts welcome, Taking it back to the Dealers Tomoz. with list. will let you know how we get on.

PS living in Van and 390 miles away from home, SO come back in 2 weeks when the spares are in is NOT an option.

Ray

PPS Beginning to miss our faithful Eberspacher Combitronic which never let us down whatever the weather.

[Guest JudgeMental]

How does it behave on gas?

 

[Rayjsj]

Do you mean Gas only Judge ? it's on Gas and electric already, But i will give it a 'Gas only' try.

 

Thanks.

[Guest JudgeMental]

Thats what you get..massive rush and then it calms down but should still be operating correctly. The thing with blown air is, you end up with a hot head and cold feet due to air rising...much prefer ALDE heating more like a domestic boiler.

 

try it on gas just to see how it runs while awaiting more advice... :-D

 

when on electric you will hardly hear anything but heat should still be felt at outlets but far more fainter.

 

try it on both gas and electric separately...I presume you have stat on max?

[Rayjsj]

Get Heat on gas only, but still not 'Controlled' , so at least the gas regulator isn't blocked.

Looks to me (but what do I know) that the room sensor is telling the boiler to come on (cold) when it should be off, and telling the boiler to stay off (hot enough already) when it should be switching it back on. We'll see. luckily we have a 'back-up' fan heater. 1st time thats been used for a while. Thanks

Ray

[colin]

When you say 'interior temp gauge' is this the Truma electronic controller or (as I suspect) a separate part?

We find the settings on our combi4 very coarse and just a little tweak sends it from cold to hot.

[Rayjsj]

colin - 2012-10-29 7:38 PM

 

When you say 'interior temp gauge' is this the Truma electronic controller or (as I suspect) a separate part?

We find the settings on our combi4 very coarse and just a little tweak sends it from cold to hot.

 

This is the 'remote' room sensor (FF2) in parts breakdowns. Control knob, I agree very coarse, I would prefere a 'Proper' Centigrade rated contoller (like a domestic room controller).

 

Took the Van in today, It WAS a poor crimp on the spade connector to the room sensor, but the engineer replaced the sensor also, plus did all the other little jobs that we had found over our week away. SO appears to be fixed (Hope ) Very Happy with Dealer ! a Silver MMM winner from 2009

The only Autotrail dealer in East Anglia. So far a good experience. Ray

 

ps particularly happy that engineer was given consent to 'Rob' a donor unsold van, to get the spares he needed to get us, up and running properly again.

[colin]

Think you might be able to fit this http://www.truma.com/downloadcenter/panel_cp_25_installation_instruction_uk.pdf

 

asked about one for our van but as it is non E we can't fit one.

[Rayjsj]

Thanks colin, saved your shortcut.

[Guest JudgeMental]

nice one! happy winter camping! :-D

[rolandrat]

If you are in Norfolk why don't you ring Auto-Trail and call on the way home, they will probably fix all your other niggles as well. Some of our MCC members have heating issues with the larger Auto-Trails and use additional free standing heaters when the outside temperature drops. I think you could have ordered the more powerful Truma when it was being built if it had been pointed out by the supplying dealers salesman.

Good Luck.

[Derek Uzzell]

Rayjsj - 2012-10-30 8:37 PM

 

colin - 2012-10-29 7:38 PM

 

When you say 'interior temp gauge' is this the Truma electronic controller or (as I suspect) a separate part?

We find the settings on our combi4 very coarse and just a little tweak sends it from cold to hot.

 

This is the 'remote' room sensor (FF2) in parts breakdowns. Control knob, I agree very coarse, I would prefere a 'Proper' Centigrade rated contoller (like a domestic room controller).

 

 

As I mentioned in this earlier thread

 

http://www.outandaboutlive.co.uk/forums/forums/thread-view.asp?tid=26098&posts=8

 

the control-switch for Truma 'combination' air/water heaters used to have a Centigrade temperature scale on the rotary dial. However, even if you fitted the more sophisticated control-panel colin mentions, your heater will behave little differently.

 

Obtaining a comfortable living-area temperature with a Truma blown-air system is largely pot luck and will depend on the motorhome's interior layout and how thoughtfully the motorhome manufacturer has installed the heating system. If a Combi's remote thermostat has been located in an unsuitable position and/or the lengths of the warm-air trunks are 'unbalanced', there's no way that the heater will be able to perform optimally.

[Rayjsj]

Thanks Derek, Just to add, the system DID work reasonably well last night (another -7/8 c one).

But don't feel it has the control or the flexibility of the Eberspacher Combitronic in our last van, an Autocruise. As for the water, i have had one shower in the van, and ran out of hot water before the end !! not good when you have Astmha ! I put it down to my missus using too much hot water for the washing up ! then i checked and found the capacity only 10 litres. a bit 'Mean' i think. Plus only up 60c.

I thought that 'TRUMA' having virtually cornered the market, would be a better performer, than I'm finding it. anyone else finding the same ? or is it just me ? Ray

[bolero boy]

Ray, 60deg is way too hot for most people to shower in so will require some cold in the mix. This makes the equivalent of 13 litres or so usable hot water. This is sufficient for the two of us to have hot showers from our combi4E.

Ps....don't wash up just prior to your shower....

[Rayjsj]

Chris,

I'm still a bit 'Old school' and think mainly in imperial measurements, So, you are correct 60c is too hot to shower in on it's own. (60F however would be a bit 'Tepid'.) . A ban on hot water use before showers are finished has to be 'order of the day'. Ray

[colin]

I think a combi4 will struggle if you want a long luxurious shower, let alone if other half is washing up. When using van shower I try to be economical with water, not such a bad thing really as it saves filling the van with steam (or water vapour for the picky)

[Robinhood]

.....from experience, when not heating water only, unless the heating controls are set to the space-heating and 60 degree water setting (rather than the space-heating only setting), the water will take a long time to heat as space-heating gets priority, and if it is really cold, the water may not reach a viable temperature for showering (at least for two people in close succession).

 

I think this is more noticeable on our current Combi than it was on our previous C6000 series.

 

We can get two reasonable showers out of one fully-heated Combi tank, as long as the required wet, turn off, soap, rinse off cycle is employed.

 

 

[Derek Uzzell]

As far as water heating alone is concerned, there should be no performance difference between a Combi-4 and a Combi-6. Both use the same 2kW-output gas-burner setting and, when the heater has a 230V capability (Combi-4E/6E), the heat output of the 230V ‘elements’ is the same for the 4E and 6E. The significant difference between a 4 and 6 is that the latter has a 6kW blown-air heat-output capability (rather than the 4’s 4kW) which will permit the air temperature in a motorhome to be raised from cold more rapidly.

 

To optimise the usage of Truma ‘combination’ air/water heaters (and this applies to the previous C-Series appliances as well as current Combis) needs the user to understand how the things function and the heaters’ limitations. As Robinhood highlights, if space-heating-only mode has been selected, water heating will be slow as it won’t occur during the intervals when space-heating is not taking place.

 

A Combi will need more care showering-wise than a C-Series heater as its water-tank capacity is smaller (10 litres versus 12 litres). But two successive showers should be perfectly practicable as long as it’s understood that only a relatively small quantity of hot water is available to begin with and that reheating water that’s cooled down takes quite a while.

 

[Rayjsj]

Another Question, I like the look of the 'CP 25' digital controller for our Combi 4E, and am looking around for one to buy, it looks more like the 'eberspacher Combitronic' control panel that I am used to.

Also it houses a thermostat and looks a bit more 'in control' than the analogue dials we have now.

Now why didn't Autotrail fit one in the first place ? instead of giving us a 'cheap and nasty' rechargeable carpet sweeper/vacuum which is as much use as a chocolate fireguard, and don't even mention the fitted Sat-Nav...... thank goodness i kept my Tom Tom. (a bit of 'over-gilding' of the lily !). anyone know where I can get a Truma CP 25 UK control panel ?. Ray

 

 

Just looked at 'Truma's' latest adverts for the 'Combi series' , the lady asleep on the sofa of the motorhome would be slowly freezing to death in MY motorhome over the last couple of weeks or so, either that or cooked. such is the 'fine' control.

 

 

[colin]

CakTanks maybe?

Or failing that pretend you want one for a Swift and phone them as they fit them :D

[Derek Uzzell]

Rayjsj - 2012-11-07 7:41 PM

 

Another Question, I like the look of the 'CP 25' digital controller for our Combi 4E, and am looking around for one to buy, it looks more like the 'eberspacher Combitronic' control panel that I am used to.

Also it houses a thermostat and looks a bit more 'in control' than the analogue dials we have now.

Now why didn't Autotrail fit one in the first place ? instead of giving us a 'cheap and nasty' rechargeable carpet sweeper/vacuum which is as much use as a chocolate fireguard, and don't even mention the fitted Sat-Nav...... thank goodness i kept my Tom Tom. (a bit of 'over-gilding' of the lily !). anyone know where I can get a Truma CP 25 UK control panel ?. Ray

 

Miriad Products (that is on the same trading estate as Truma(UK) and shares the same building)

 

http://www.miriad-products.com/

 

should be able to tell you about the availability of a CP-25. The price quoted in Truma's 2012 Camping World catalogue is £171.41 (VAT Inc).

 

A CP-25 replaces the manual controls of a Combi-E and adds a timer feature. I don't know how useful the latter would prove, though I do remember a Hobby owner saying in MMM that specifying the timer-only Truma ZUCB unit as an option had been a waste of money.

 

I believe you'll find that a CP-25 controller does not house a thermostat and that, although it's possible to set a specific room temperature via a CP-25, (as I said earlier) the Combi will behave little differently to how it does currently.

 

It's likely that Truma offers Combi-E appliances to leisure-vehicle manufacturers as complete 'kits' that include either the two manual controls or a CP-25. Your Combi-E has the standard two manual controls and you may find that replacing these with a CP-25 may prove tricky (or even impracticable), so I suggest you begin by asking the Truma(UK) technicians about this.

 

http://www.truma.com/uk/en/home/service-center.php

 

There's an instructional CP-25 video here

 

[JohnP]

According to Truma if the CP25 controller is fitted to the Combi 4E it may also mean changing the PCB board if your Combi is over one year old. Something to do with compatibility. To change the two components costs about £400.00p

Also the CP25 will not be available until after Christmas 2012.

[Brian Kirby]

I'd suggest giving yourself longer to get used to the new system. The Truma control has the merit of being simple, and once the heater is operating as it should, which yours hopefully now does, is quite sensitive. We find a setting around 5 is about right in our van.

 

They take a while to work up to temperature, initially running quietly with little heat delivery while they "sniff" the air. After a few minutes the fan speed ramps up, and it does its impression of a 747 on take off until it reaches the set temp. Once up to temperature the fan gently subsides to its lowest speed and will then quietly cycle up and down, possibly going on and off, to maintain the set temp.

 

It is the location of the temperature sensor that causes most problems, as converters do not always site them intelligently - for example opposite a hot air outlet. However, given a reasonable a location, often by the hab door where it is likely to be a bit cooler, the system performs quite well in my experience.

 

In truth, it matters little whether or not there is an actual temperature scale, as a temperature is merely a number, and the sensor reacts only to the temperature at its location - which may not be where you are. So, achieving comfort would be largely a matter of trial and error whatever demarcation were used for the intermediate steps. However, once you find the setting that suits you, you can more or less leave the dial at that position, and just let the heater to do its job.

[Robinhood]

Brian Kirby - 2012-11-08 5:23 PM

 

I'd suggest giving yourself longer to get used to the new system. The Truma control has the merit of being simple, and once the heater is operating as it should, which yours hopefully now does, is quite sensitive. We find a setting around 5 is about right in our van.

 

 

.....though I would assume that this is on the older control, with a 1 to 8 temperature scale.

 

The current Combi is likely to have shipped with the newer control, with a 1 to 5 scale.

[Rayjsj]

The room sensor in our van is mounted above the power sockets in the kitchen area (in direct line of the electric kettle when it boils !!) We will leave it a few weeks before we spend any more money though. It is a 1-5 dial for heat control, optimum seems about 3 . The '747 roar' scared my missus to death, she thought the whole van was about to explode. Just got to get used to it, i suppose.

thanks for the input. Ray