# Truma Combi Fault - Advice Req'd Please



## Blizzard (Sep 21, 2009)

Hi All, 

Just snuck away for the Bank Hol and developed a fauly on the Truma Combi while we were away.

Whilst on hook up, we only usually use "electric only" to heat the water and/or run the heating.

This was working fine until yesterday when the water would not heat. I tried the heating on "electric" and again, that would not warm up. The circulating fans were working ok. 

On switching to gas, both hot water and heating worked fine.

I have checked the main 20A fuse for the water heater and that appears fine.

I'll be speaking to my Service Manager during the week, but was wondering if anyone on the forum knows if there is another fuse, or has heard of a similar problem in the past. 

Thanks, 


Ken.


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## Rapide561 (Oct 1, 2005)

*Electric*

Hi

Do a quick check now of this.

Switch the boiler to electric only and at the 1800 watt setting. You should have one orange light on the power selector - is this the case?

On the other dial, the one where you can select hot water or heating and hot water, you should have a green light, and also, when the water heater element is on, an orange light within the same dial as the green light.

What lights have you got?

Russell


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## Blizzard (Sep 21, 2009)

Russell,

Apologies - I should have anticipated a quick response from someone  but I had a pup tent, an inflatable kayak and a load of wetsuits & lifejackets to dry out in this afternoon's sun.

Just had a quick look at the controls and the first control shows no light at all when selecting 1800w or 900w.

The other control is showing both amber and green.

Cheers, 


Ken.


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## Rapide561 (Oct 1, 2005)

*Boiler*

Hi

If I have understood correctly, then the unit is not getting 230v power.

Look under your L shape seat and ensure the switch is on, and no MCB's are tripped.

Are all 230v sockets working?

Other than that, I can't suggest anything.

Russell

Might be worth giving www.trumauk.com a call tomorrow


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## Codfinger (Jan 11, 2008)

*combi fault*

Just a thought as I recall there is a thermal cutout on the heating unit which has to be manually reset (just push the button in a bit like on an extension lead) It's important to let the system go through its cooling/shutdown cycle.
Chris


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## Blizzard (Sep 21, 2009)

Thanks both  

All sockets, trip switches and fuses are ok and working as normal. 

If the thermal cut out reset switch is the one under the red plastic slide on the side of the boiler, then this was tried yesterday and didn't work.

I also always allow the unit to cool down fully and switch itself off before knocking the main power off, so don't think that's the problem.

We'll see what Swift or my service team come up with, but I was hoping there was an easy diy fix without having to take the van in.



Ken.


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## Codfinger (Jan 11, 2008)

*Combi*

Oh well best of luck.
Chris


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## philsil (Jul 24, 2007)

Don't seem too bright these units. We've got the opposite 240v good, gas dead. Alan Kerr cannot fix it after swapping PCB and gas switch.


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## Rapide561 (Oct 1, 2005)

*Boiler*

Last chain of thought from me

Here are two pics of my boiler control. The one "with electric" shows all lights that are illuminated when the boiler is operating on electric.

The pic "without electric" shows the illuminated lights when not operating on electric.

If your control shows the "without electric" images when you are trying to use the boiler on electric, this suggests no 230v supply is present.

Sorry I can't help further.


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## missmollie (Sep 30, 2005)

I also have one these boilers in our Bolero, won't work on electric and sometimes won't work at all, has been back to Todds in Preston they said it was a faulty connection on the electrics even though I had double checked everything before I took it in, didn't work when I got the van home from them. it will be going back in once I return from France.


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## Blizzard (Sep 21, 2009)

missmollie said:


> I also have one these boilers in our Bolero, won't work on electric and sometimes won't work at all, has been back to Todds in Preston they said it was a faulty connection on the electrics even though I had double checked everything before I took it in, didn't work when I got the van home from them. it will be going back in once I return from France.


Sounds like a different problem to ours, as ours has worked perfectly for close to a year and is fine on gas.

Phone diagnosis is _possibly_ a knackered element and it's going in next week for a look.

Hope you get yours sorted.

Ken.


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## Rapide561 (Oct 1, 2005)

*Truma*

Ken

I had a knackered element in my boiler last November - see thread on here - but the orange light still lit, even though the element was not working.

Cheers

R


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## Blizzard (Sep 21, 2009)

Hi All, 

Just a quick update.

Dealer has stated that a 10 amp fuse had blown on the "PCB" and due to the fact that fuses are not covered by warranty (rightly so), this one has cost me £35 labour.

What I need to know for future is, where is the "PCB" and is it easily accessible for me to change the 10 amp fuse, should it blow again or is this a job best left to the dealer or qualified sparky.

Thanks in advance, 


Ken.


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## Rapide561 (Oct 1, 2005)

*Fuse*

Hi

Is that a fuse within the boiler or a fuse within the electrics of the motorhome?

Russell


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## CLS (Jul 25, 2005)

The Truma C-series appliance carries a fuse (or fuses) in the electronic control-unit attached to the outer surface of the heater. Removing the top 2 screws from the holder will reveal the pcb 

Mark


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## Blizzard (Sep 21, 2009)

*Re: Fuse*



Rapide561 said:


> Hi
> 
> Is that a fuse within the boiler or a fuse within the electrics of the motorhome?
> 
> Russell


Russel,

Not sure, which is why I hoping someone would know where the PCB is situated,

Ken.


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## Blizzard (Sep 21, 2009)

CLS said:


> The Truma C-series appliance carries a fuse (or fuses) in the electronic control-unit attached to the outer surface of the heater. Removing the top 2 screws from the holder will reveal the pcb
> 
> Mark


Mark,

I'll have a look at it in the daylight and see if I can identify where the fuse is situated.

Thanks,

Ken.


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## rayc (Jun 3, 2008)

Blizzard / Russell. These are the 2 relavent pages from the manual. There are fuses protecting the 12v and 230v circuits. The 230v /10amp one you are talking about is in the Power Electronics unit, item 13 in the schematic . Ray


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## Blizzard (Sep 21, 2009)

Ray, 

Thanks very much for that, I can see exactly where I need to be now,


Ken.


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## kazzzy (Apr 9, 2006)

I have the same problem with my boiler no electric heating but works fine on gas, also no orange light on selection switch but amber and green on temp selection dial work fine, I have checked the fuses on the PCB and they are all fine, cant get to the element easilly due to the installation position all 240V supply seems OK at distribution panel below boiler so I am stumped will be giving a Truma engineer a call but suspect its going to cost, any other suggestions welcome.


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## rayc (Jun 3, 2008)

kazzzy said:


> I have the same problem with my boiler no electric heating but works fine on gas, also no orange light on selection switch but amber and green on temp selection dial work fine, I have checked the fuses on the PCB and they are all fine, cant get to the element easilly due to the installation position all 240V supply seems OK at distribution panel below boiler so I am stumped will be giving a Truma engineer a call but suspect its going to cost, any other suggestions welcome.


You appear to have the same symptoms as Blizzard described on his 2nd post on page 1. Have you checked the 230v fuse, 10A slow blow, which is in the Power Module. See my post above with the layout of the boiler, the Power Module is item 13. I presume you have tried the reset button which is part of the same module?


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## kazzzy (Apr 9, 2006)

No reset button visible on mine do you need to take the cover off the module to access it as there is no button on the outside? :?


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## kazzzy (Apr 9, 2006)

I lied, just had another look at the picture posted and noticed the reset switch was on the heater element cover not the control board so had a look and found it was out just reset it and all works fine, didn't see it before as the installation of the boiler means I have to put my arm right round the back to access it, Thanks for the advice.


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## Blizzard (Sep 21, 2009)

Mine's sorted for the future too  

Removed the 2 retaining screws from the control unit cover (as advised) and the 10 amp fuse is readily accessible.

Sod's Law being what it is, now that I'm prepared it will never blow again.

Thanks again for all the advice,


Ken.


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## UncleNorm (May 1, 2005)

And finally...

... the fuse on ours proved to be fine; it was the *fuse holder *that failed to hold the fuse tightly. I nipped the clips tighter and refitted the fuse. All is well at the present. :roll: :wink:


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## philsil (Jul 24, 2007)

the internal fan was replaced at Alan Kerr's. now have gas heating.


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