Truma Combi - blowing cold

[Thai Bry]

Robinhood - 2020-12-30 6:32 PM

 

Thai Bry - 2020-12-30 6:01 PM

 

Thanks once again Robin.

I'll see if I can get a mirror on a stick to squeeze down the back of the unit.

Looking really difficult- if it's the fuse that needs replacing.

I know the Combi6E is different, but the arrangement is very similar. TBH, I managed with a mirror, and then by feel, in a very tight space. BUT, the fuse is considerably more easy to remove than to replace under those conditions.

I might give this a go, as I'm not doing anything or going anywhere in the foreseeable future!!

[Thai Bry]

Thanks for the picture Derek

[Robinhood]

..odd about the picture - it shows up quite happily on the PC, but not on my 'phone (where it has been "red crossed").

 

Anyway, you now know where the fuse is.......

[Thai Bry]

Thanks to all that have given me ideas and advice on how to remedy the fault on my Truma boiler

[Thai Bry]

Robinhood - 2020-12-30 7:30 PM

 

..odd about the picture - it shows up quite happily on the PC, but not on my 'phone (where it has been "red crossed").

 

Anyway, you now know where the fuse is.......

Just an update

The plot thickens!!

Went to the van this morning, turned on the electrics, put the heater on it's winter setting.

Both Yellow & Green lights are lit, but still no heat from the ducts.

 

Looking more like a PCB fault now.

[Derek Uzzell]

Thai Bry - 2020-12-30 6:28 PM

 

...Just checked & sadly I can confirm that the Yellow light on the dial does not come on when I'm on the electric side of things.

Just the green light is showing.

From what you said earlier, at one stage the yellow light was illuminating on the power selector switch when you selected the 230V setting.

 

I’m not familiar with Hymer electrical system practice, but I’d expect there to be a 230V consumer unit somewhere with an RCD and MCBs. I’d want to check the consumer unit to ensure that nothing is ’tripped’ and the 230V power is actually reaching your motorhome (eg. plug a 230V appliance into one of the Hymer’s 230V sockets). If the sockets are ‘live’ and none of the MCBs are tripped, I’d try switching the power selector switch between its various settings several times. (Try the combined 230V + gas seiiting as well as the 230V-only setting to see if that will bring the yellow light on.)

 

Logically, if the power selctor switch’s yellow 230V indicator light doesn’t illuminate, the heater will probably not heat using 230V electricity, but that doesn’t automatically mean that the fault lies with the heater itself and that the red reset button needs to be pressed or the heater’s 230V fuse has blown - It might be that the power selector switch is the culprit. What you want to avoid is involving a Truma specialist if there’s a simple easily-addressed reason for the 230V problem.

 

A few years back I was ‘called’ to a French Rapido motorhome by a French campsite warden. The Rapido’s owners had connected the motorhome to a 230V supply-pedestal but their Dometic AES fridge refused to switch from gas to 230V operation. The explanation for this happening proved to be that the 230V consumer unit (located in a lounge seat base) had lost its protective cover and the owner had stuffed the seat base with ’junk’ that resulted in two of the consumer unit’s three MCBs being knocked to their Off position. One of those MCBs protected the fridge’s 230V power supply and the other MCB protected the 230V supply to the battery charger.

[Thai Bry]

Hi Derek

 

I will try your suggestions.

 

I've checked the main RCD and this has not tripped.

All the sockets are live and giving power to electrical appliances, such as phone chargers.

 

Many thanks

Brian

[peterjl]

Hi

 

Except from manual

–Heating with drained water systemSelect gas or electrical operation using the power selectorswitch. Illumination of the yellow LED (g) on the powerselector switch indicates that the unit is operating with 230 V.Move rotary switch on control panel to operating position (m).Turn the rotary switch (h) to the desired thermostat setting(1 – 5). The green LED (k) for operation is lit and simultaneouslyindicates the position of the selected room temperature. Theyellow LED (p) will be lit only when the temperature of theunit is below 5 °C

 

This says two different yellow leds and only one yellow light is lit when when temp below 5C.

Not sure if that helps.

 

I have been confused by these lights in the past.

 

Peter

[Robinhood]

Peter,

 

the two yellow lights detailed are in different dials.

 

The yellow "backlight" behind the "power selection" dial is the indicator that mains has been selected (and is available). AFAIR, this is the only light in that dial. If this is showing when mains is selected via that dial, then the C6002EH is seeing mains electricity, and it is unlikely the problem is anywhere in the mains feed (including the fuse already highlighted in posts above). Of course, if that light doesn't illuminate when mains is selected, then there is most likely a fault in the mains feed.

 

In the C6002EH manual, or at least the version I have, a green light in the other, "Control Panel/Thermostat" dial denotes the fact that the unit is switched on. There is, as you say, another (yellow) light that is supposed to show when the water temperature is below 10 degrees (not 5 in my manual), BUT, the way the manual is written, this covers the circumstance where the unit contains water, but you have set "space heating" only. It is silent on whether this light will initially come on if the unit is run empty of water if the demand is only for space heating. I can conjecture that this light will still come on in low temperatures, but somewhat more briefly as the internals of the unit without water will heat up rather more quickly than with, but this ,<>is only conjecture..

 

We've been around the houses with the lights thing, and I'm still not sure where the yellow light (which has and hasn't been seen) is located.

 

So, a clarification question for Brian;

 

It appears you've seen a green light, and sometimes a yellow light, and sometimes not. Is this yellow light adjacent to the green light in the same "Control Panel/Thermostat" dial, or is it in the other "Power Selector" dial?

 

 

[peterjl]

Hi RobinHood

 

I didn’t express myself very well, I was wondering which yellow light was being referred to.

 

I know from personal experience of getting these lights confused when trying to isolate a problem.

 

Petrr

[Robinhood]

Wasn't having a go at you, Peter.

 

Your post just re-sparked the though that I still wasn't entirely sure which yellow light(s) were being described upthread, and that, if it weren't the one indicating that mains power was getting through, then it would rather focus the investigation.

 

;-)

[Derek Uzzell]

Operating instructions for a Truma Trumatic C-6002EH appliance can be downloaded from here

 

https://www.truma.com/uk/en/service/self-service/product-family/truma-c-heaters

 

The relevant guidance in this instance is as shown on the attachment below.

 

I don’t recall ever choosing to use the 230V heating option on my C-6002EH heater when the heater was empty. But - having selected 230V operation on the power selection switch, having turned the control panel’s inner rotary knob to 9 (maximum room temperature setting) and having turned the control panel’s outer rotary knob to the 2nd from bottom position (Winter mode (heating without hot water requirement)) the power selector switch should then illuminate with a fairly faint yellow ‘backlight’ (as Robinhood has said) and a green LED and an orange LED should light up on the control panel.

 

If a hot water requirement has been chosen (with water in the heater of course) the orange LED on the control panel will stay illuminated until the water has got hot and then go out. I vaguely recall asking the Truma techs what would happen with the orange LED if Winter mode (heating without hot water requirement) had been selected and the heater was empty of water, and being told that the orange LED would go out very quickly.

 

Regarding operating a C-6002EH empty of water, Truma’s FAQ advice is here

 

https://www.truma.com/uk/en/faq/water-volume-trumatic-c-6002-eh

 

https://www.truma.com/uk/en/faq/water-container-trumatic-c

[Thai Bry]

Robinhood - 2020-12-31 1:15 PM

 

Peter,

 

the two yellow lights detailed are in different dials.

 

The yellow "backlight" behind the "power selection" dial is the indicator that mains has been selected (and is available). AFAIR, this is the only light in that dial. If this is showing when mains is selected via that dial, then the C6002EH is seeing mains electricity, and it is unlikely the problem is anywhere in the mains feed (including the fuse already highlighted in posts above). Of course, if that light doesn't illuminate when mains is selected, then there is most likely a fault in the mains feed.

 

In the C6002EH manual, or at least the version I have, a green light in the other, "Control Panel/Thermostat" dial denotes the fact that the unit is switched on. There is, as you say, another (yellow) light that is supposed to show when the water temperature is below 10 degrees (not 5 in my manual), BUT, the way the manual is written, this covers the circumstance where the unit contains water, but you have set "space heating" only. It is silent on whether this light will initially come on if the unit is run empty of water if the demand is only for space heating. I can conjecture that this light will still come on in low temperatures, but somewhat more briefly as the internals of the unit without water will heat up rather more quickly than with, but this ,<>is only conjecture..

 

We've been around the houses with the lights thing, and I'm still not sure where the yellow light (which has and hasn't been seen) is located.

 

So, a clarification question for Brian;

 

It appears you've seen a green light, and sometimes a yellow light, and sometimes not. Is this yellow light adjacent to the green light in the same "Control Panel/Thermostat" dial, or is it in the other "Power Selector" dial?

 

Hi Robin

 

For full clarification on my system.

I have 2 dials for the Truma system.

One is called the Control panel and the other is called the power selector switch.

The upper one which is the winter/ summer selector dial with a temperature dial in the middle.

So you can select water heating only, at 40 or 60 degrees temperature, or gas and water heating

On this dial there are 3 visible lights that may show.

Yellow , meaning that the unit is functioning but not up to the set temperature, and the other is green, when up to temperature and operating correctly.

When the system has reached temperature, the yellow light goes out and only the Green light is lit.

If next to the green light a red light shows, this denotes that there is a gas failure.

Either not igniting or low on gas.

 

The lower dial - which is the "Source selector" is for either electrics or gas selection as the power source.

On this dial, there should be a Yellow light showing, which depicts that the system is working when on electric settings.

 

Currently on mine it is this light that is not light, which according to the manuals, tells me that the electric side of things is showing a fault.

I've been in contact with Truma technical who suggest that the elements may have a defect.!!

 

I've now booked the van in at a Hymer/ Truma specialist to have this fault rectified.

Hopefully it's the fuse at the back of the unit - totally inaccessible - on my unit that needs replacing as you suggested.

 

I'm sorry for any confusion caused in my previous posts, and thank everyone for their input.

 

Regards

Brian

[Robinhood]

Thanks Brian.

 

That makes things completely clear.

 

As you're not getting the yellow light in the power selector, the fuse has to be at least a suspect (especially as you appear to have checked the remainder of the 230V route). As I've said to you, these fuses have been a relatively common problem with both the 6002EH and the newer Combis. The feeling is that they are a little under-spec for start-up current, despite being slow-blow (and there was some speculation, after a spate of them in Combis, that Truma might have had a sub-standard batch). I carry a spare with me now........somewhere.

 

The difficult replacement of the fuse on my Combi resulted in fault-free running for the remainder of my ownership, so patently the fuse might go without other fatal accompaniments. Viz the elements, however, it is just possible that the failure of one or more element might cause a surge, and blow the fuse. If this is the case, then its going to be somewhat more expensive :-(

 

The Combi in my current 'van is somewhat more accessible.

 

Good Luck!

[Thai Bry]

Robinhood - 2020-12-31 5:04 PM

 

Thanks Brian.

 

That makes things completely clear.

 

As you're not getting the yellow light in the power selector, the fuse has to be at least a suspect (especially as you appear to have checked the remainder of the 230V route). As I've said to you, these fuses have been a relatively common problem with both the 6002EH and the newer Combis. The feeling is that they are a little under-spec for start-up current, despite being slow-blow (and there was some speculation, after a spate of them in Combis, that Truma might have had a sub-standard batch). I carry a spare with me now........somewhere.

 

The difficult replacement of the fuse on my Combi resulted in fault-free running for the remainder of my ownership, so patently the fuse might go without other fatal accompaniments. Viz the elements, however, it is just possible that the failure of one or more element might cause a surge, and blow the fuse. If this is the case, then its going to be somewhat more expensive :-(

 

The Combi in my current 'van is somewhat more accessible.

 

Good Luck!

Thanks Robin

 

I'll let you know via a PM when things are resolved

[Brian Kirby]

You can probably save yourself some expense, Brian, if you can remove sufficient of the wardrobe enclosure to allow full access to the heater. I remember a conversation with a Truma tech some years back during which he said that most faults could relatively easily be checked and resolved once the heater was on a workbench, but that getting to that point often cost the owner more in time charges than the repair itself, as the converters did not give adequate consideration to access for removal of the heater. On the basis of that advice, anything you can do to remove access impediments beforehand, so that they can get straight to the heater as soon as it gets to them, would seem to be time profitably spent.

 

Most of the stuff is screwed together, so it should be possible to dismantle without causing any damage. Then, possibly, remove the arisings from the van and place somewhere safe ready for reassembly once you have the van back. Unwelcome opportunity to overcome Covid boredom? :-)

 

Good luck. Let's hope it is just the fuse - 'though fuses shouldn't fail under normal use. Unfortunately, a failed heater element would be an obvious candidate for that failure. I gather these electric heating elements do have something of a reputation for failure. Fingers crossed.

[Thai Bry]

Brian Kirby - 2020-12-31 6:28 PM

 

You can probably save yourself some expense, Brian, if you can remove sufficient of the wardrobe enclosure to allow full access to the heater. I remember a conversation with a Truma tech some years back during which he said that most faults could relatively easily be checked and resolved once the heater was on a workbench, but that getting to that point often cost the owner more in time charges than the repair itself, as the converters did not give adequate consideration to access for removal of the heater. On the basis of that advice, anything you can do to remove access impediments beforehand, so that they can get straight to the heater as soon as it gets to them, would seem to be time profitably spent.

 

Most of the stuff is screwed together, so it should be possible to dismantle without causing any damage. Then, possibly, remove the arisings from the van and place somewhere safe ready for reassembly once you have the van back. Unwelcome opportunity to overcome Covid boredom? :-)

 

Good luck. Let's hope it is just the fuse - 'though fuses shouldn't fail under normal use. Unfortunately, a failed heater element would be an obvious candidate for that failure. I gather these electric heating elements do have something of a reputation for failure. Fingers crossed.

Many thanks Brian.

 

I've looked at the base of our wardrobe, beneath which sits our Boiler unit.

Typical of Hymer it looks like a solid base, however there seems to be plastic caps, which I presume covers some kind of fixing screws. If I remove these, I'm still not able to get to the main PCB, where the main fuse would be located, as described by Robin in an earlier post, and picture posted by Derek.

I will take your valued advice, and if remove-able I can do this prior to taking the van to be looked at.

If it turns out to be the elements inside the boiler, that is a different story and something - like you - I'm keeping my fingers crossed that its not the issue.

 

Many thanks for your advice

[Derek Uzzell]

Attached below are images of a Trumatic C-6002EH’s two controls.

 

There’s no specific position for the controls - they may be oriented vertically (with the Power Selector Switch above the Control Panel or vice versa) or horizontally (with the Power Selector Switch to the left of the Control Panel or vice versa).

 

Brian’s description of his heater’s operation mentions the yellow lamp on the Control Panel. This is referred to in Truma’s instructions as “q = Yellow- Boiler heating phase monitor lamp” and relates to the temperature of the water in the heater’s boiler. The yellow lamp illuminates when the heater is turned on and goes off when the water in the boiler has reached the appropriate temperature, at which point water-heating will shut down. If hot water is subsequently used (say for showering) causing the water-temperature in the boiler to fall, the yellow lamp will illuminate again and water-heating will recommence. If air heating is chosen (and there’s water in the boiler) the water will be heated as a by-product. Anyway, the significant thing is that the control-panel’s yellow lamp relates to the temperature of the water and not to the 'room temperature’.

 

This 2012 forum thread discussed the operating principles of a C-6002EH.

 

https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/Trumatic-C-EH-heater-and-hot-water-system/28220/

 

I’ve never had much difficulty with the ‘logic’ behind this appliance’s two controls, but presumably integrating all the feature/options into a single digital control-panel (the CP Plus panel) was felt to be be an improvement and more comprehensible to users.

 

[Thai Bry]

Just a quick update to my issues.

 

It's now confirmed that my C 6200 EH unit is completely bust.

The elements have failed - diagnosed by a certified Truma agent - and as the unit is now a discontinued device, I'm having it replaced with a brand new Truma Combi 6E.

So looking like learning the new heater controls all over again, before we can set off on any adventures, when restrictions permit of course. So plenty of time to get used to the new system.

 

May need to go and lie down in a darkened room, as it's not a cheap replacement, however the van was brand new when we bought it in 2007, so the cost spread over 14yrs is not too bad. Well that's what I'm telling myself and the better half.!!

 

Just a major thanks to all that have given their advice to me.

 

Thai Bry

[Brian Kirby]

Ouch!! You have my sincere condolences Brian. There, I hope that makes it all better for you! :-D

 

I think the darkened room is undoubtedly the best short term option, though I'd recommend a half decent bottle of your favourite tipple as well. It will dull the senses in the meantime, but when you come round the hangover will make the cost of the heater seem totally insignificant!

 

On the bright side, at least you get a later (so presumably improved) design, and a brand new heater, for the next 13 years of touring around. Hope it all goes well.

[Thai Bry]

Brian Kirby - 2021-01-26 11:26 AM

 

Ouch!! You have my sincere condolences Brian. There, I hope that makes it all better for you! :-D

 

I think the darkened room is undoubtedly the best short term option, though I'd recommend a half decent bottle of your favourite tipple as well. It will dull the senses in the meantime, but when you come round the hangover will make the cost of the heater seem totally insignificant!

 

On the bright side, at least you get a later (so presumably improved) design, and a brand new heater, for the next 13 years of touring around. Hope it all goes well.

Many thanks Brian for your kind words.

 

Hoping that all goes well with the newer version of our Truma device, the brightside/upside is our downsizing project will have to go on hold for a few more years.

Well that's what I've told "Her who must be obeyed"......