Kingham Truma Combi heater over heat problem

I can see the small plastic sticky patches - they just show up in your photo. If you ask A/S will send you a sheet of them in the post.  They did for me several years ago.  I am pretty sure that they are the stickies and not prise out caps.  It rather sounds as though they have left too little ventilation.  You will need to be very careful that you do not cover either of the plastic grilles as, without free access, the combi will inevitably overheat.  When you have the top off do check that blanking plkugs re in any unused outlets.  My wardrobe used to get very hot because one had fallen out as it had not been put in properly in production.

snow863 wrote:I dont think my problem is due to ventilation issues. It is the heater electric element thats not working.

If the fuse has blown, it could well be an overheating problem.

Have a look at this fact sheet in case you need to do a modification.

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On the photo below (if your panel is similar to ours), if the 240 volt plug icon is missing, just below the degrees Celsius icon on the right, the chances are your fuse has blown.

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Ok so that was a waste of a huge amount of holiday time!
Finally got to re-set button but had to take whole casing apart (top and back panels) to get there!
To do this had to strip the bed, empty under bed storage and unscrew 14 screws 8 of which were f'ing hard to reach..
After finally getting there and pressing re-set... it made no difference... still no hot water!
Then attempted to get to the 240v fuse on the boiler and the screws on the cover for that are already rounded... brilliant!
Given up, put it all back together and switched to gas.... Now have new problem LPG tank is getting low... aaaaargh!!
2.5 hrs drive each way to nearest supplier.
Am not happy!

Cheers Dave ... I have the same control panel as yours and yes the 240v plug icon is not on display. Overheat re-set hasnt worked. So I guess it must be the boiler 240v fuse which we cant get to because someone has been there before and rounded the screws on the casing cover.
Given up!

You sure they are rounded?

I'm fairly sure they are security screws on ours, so they may appear rounded if you can't see them very clearly, or have to do it by feel.

Can't be certain as I've never changed the fuse - I'm too big to get in, as said before.

They are hard to see Dave but nothing we have on board will fit them.
Sadly the nearest repairer is also 2.5hrs drive from here!

The screws on the Truma are torx screws, when I had the problem on my Broadway with the 240v fuse I found that AS had fitted the unit facing the rear wall with about 4" clearance, I had to use a torch and small mirror to replace it with difficulty.

Mine appeared to blow after running on 240v and closing the shower vent because it was too hot, there are 4 vents on my unit but only 3 used.

Thanks Barry will try a Torx screw driver bit if I can find one.
Any idea what size? Would be great to know as will need to go round site asking if anyone has one. I cant even get a decent view of the screw heads!

AndyRoyd wrote:The screws on the Truma are torx screws, when I had the problem on my Broadway with the 240v fuse I found that AS had fitted the unit facing the rear wall with about 4" clearance, I had to use a torch and small mirror to replace it with difficulty.

Mine appeared to blow after running on 240v and closing the shower vent because it was too hot, there are 4 vents on my unit but only 3 used.

Thanks Barry.

Yet more evidence to support Dare-devil-Dennis and several others who have concluded that overheating is the cause of blowing fuses.

I won't know for sure until after it has been thoroughly tested over the winter with both space and water heating going full blast, but with the computer fans running the bottom of the wardrobe is definitely a lot cooler. See the link to the fact sheet that I posted earlier.

snow, where are you camping? I'm interested in your comment re the nearest lpg gas being so far away....
do you have the mylpg app or web access?
hope you get your issue resolved..some Truma units seem to have issues....our latest one seems fine.

re your own issue: from earlier 'Kingham heater' threads it seems that the forward heating vents are reduced in size to much slimmer pipes than those normally used (and used in the rear bed/washroom area) in most installations, so much so that the neating in the front of the van is very poor.

It's been reported that these smaller pipes seriously reduce the fwd heating flow and was wondering if they might be restricting airflow sufficiently to cause a heat build up, back up the pipework, in turn resulting in an overheat situation?
the comment re closing the washroom vent causing the issue is a big clue....

Hi Chris
We are on the north coast of Scotland by Cape Wrath.
Will check out the lpg app... thanks for that!
Its the water heater that overheated/tripped. We didnt have the heating on I really dont think that this is a heating issue.
Our heating works very well but I never shut any of the vents. I like my shower warm it dries the towels and keeps away any mould etc. We have been away in really cold weather including getting stuck in snow with the beast from the east and been warm and cosy all through it.
We do use a windsxreen/bonnet cover when its very cold which helps keep the cab area warm.
Still need to find a torx screw driver but we should be ok if gas lasts.

Hopefully in your search for LPG, you can also locate the nearest say Screwfix, Tool Station or other retailer to purchase a Torx Driver set for as little as a fiver or less depending on assortment of other bits?

Its pretty remote up here!
Nearest lpg station is Ullapool  which is a 2.5 hr trip each way with a B&Q etc.
I'm told there is a "wee hardware store" at Loch Broom which is only 1 hr 45 mins drive each way!!
We'll sit it out and hope lpg lasts til friday when we were heading towards Ullapool anyway.
We have a fan heater and electric kettle.

Just remember to keep Torx screwdrivers on board next trip!!

Heading South a bit today so hope to find some where to get LPG and a fuse which is described in the manual as a "10 A, quick-acting, interrupting capacity “H” ".
Does anyone know what that is and if so can they send me a link to a photo of one.
We dont want to take the casing apart to look at it until we get on site tonight. Ideally just want to buy fuse on way to site.
I have googled 10 A, quick-acting, interrupting capacity “H” but what we find doesnt seem to memtion type H. 
I think its a plain glass type but is it 20 or 30mm long and is it 5 or 6mm diameter? Or is it the ceramic type? Or the ones with special couloured glass or something completely different.
Have tried the nearest dealership (250 miles drive) and AS again but still waiting on call backs.... sigh
Hoping soneone here knows???

snow863 wrote:
I have googled 10 A, quick-acting, interrupting capacity “H” but what we find doesnt seem to memtion type H.

My manual says 10A slow acting.

When Truma specify interrupting (or breaking) capacity H. they are refering to the 230V fuse. From your other posts I think you are planning to replace the 12V fuse. The spec for the 12V fuse is simply "10A slow-acting 5x20mm.

The 12V fuse is the one next to the overheat reset button (multi coloured on mine) and is easy to access, you just slide the panel upwards.
You need to start dismantling the unit to get to the 230V fuse. I note the comment in the manual re the 230V fuse "this fuse must only be replaced by an expert!" OMG

snow863 wrote:Heading South a bit today so hope to find some where to get LPG and a fuse which is described in the manual as a "10 A, quick-acting, interrupting capacity “H” ".
Does anyone know what that is and if so can they send me a link to a photo of one.
We dont want to take the casing apart to look at it until we get on site tonight. Ideally just want to buy fuse on way to site.
I have googled 10 A, quick-acting, interrupting capacity “H” but what we find doesnt seem to memtion type H. 
I think its a plain glass type but is it 20 or 30mm long and is it 5 or 6mm diameter? Or is it the ceramic type? Or the ones with special couloured glass or something completely different.
Have tried the nearest dealership (250 miles drive) and AS again but still waiting on call backs.... sigh
Hoping soneone here knows???

The fuse size is 5x20mm, fast blow type F, the H refers to a ceramic type. will not break the casing when it blows whereas glass can sometime break.
When mine blew I just happened to have a pack of suitable speed glass type so used one of them.

Cheers Barry did the glass fast blow last ok? They are easier to find up here.

Flipping Heck snow863, Cape Wrath, not the best place to have to find a torx bit screwdriver. I know it doesn’t help much but following others having similiar issues on this forum, I have kitted myself out with all sorts of different screwdriver bits and a pack of six of the relevant fuses. I am not trying to make you feel worse but, I am now also useful to others motorhome owners who have emergencies! So are there any other van owners on your site up there that can assist you. If not search out camping sites and go and ask other for help. If you have already tried this, then forget what I have said. Another option is to ring AS Service section/ shop,if they are open of course!(holidays!) and get then to send some fuses and possibly an emergency torx screwdriver, by rapid post!

Really hope you get sorted. When you get back you can redesign the unit casing to allow easier access and open it up a bit to allow more air to circulate. This is a well known problem. Have a word with Dare-devil-Dennis, If I am not mistaken, I think he sorted out a similiar issue very effectively. Our Truma heater is fortunately placed under our wide seating area with plenty of air space and vents to keep it cooler. The fuse is a lot more accessible but I am sure I will have to use a mirror as the fuse compartment is facing the outside wall! We haven’t had an issue so far, but I am now thinking of adding more vents as well as widening the existing one!

Good luck with your quest snow863, keep your chin up! let us know how you get on.

Pete

snow863 wrote:Cheers Barry did the glass fast blow last ok? They are easier to find up here.

It has been in for about a year and no problems, I am mostly on EHU so use electric for the water in summer and for heating in winter.
I have used these type of small glass fuses extensively over the years in an industrial environment without the glass breaking, only use the small ceramic in explosive or flammable areas.

Found torx screw driver in van eventually after digging about various cupboards so solved that one.
Yup Pete.. couldnt be more remote really even the Orkneys have hardware stores and LPG!
Finally got called back by Truma who told me to use any 10amp  fast blow glass type 5x20mm . They said the type H just means fast blow.
The (not so) local AS dealer told me no one else can fix it but them in Scotland and naturally strongly advised us to drive all the way across Scotland to them. Of course they want to take my money! Might as well.go home if we do that! Would rather stay on gas or even manage without (have kettle and fan heater on board).
Going to buy a fuse if we can and then have a look at it.
Finding this whole saga quite ridiculous for a simple fuse change.

snow863 wrote:...The (not so) local AS dealer told me no one else can fix it but them in Scotland and naturally strongly advised us to drive all the way across Scotland to them...

And they would be in Perthshire, would they? Could be worse, you could have to deal with the Ayrshire mob.

If you're still in need of a part and heading for Ullapool, try Loch Broom Hardware on the front. An Aladdin's cave of wonders!

Cheers Weegie Sat Nav set for Loch Broom Hardware am hopeful they will sort us out! Apparently there is LPG there too.. bonus!
Not going near the AS dealers especially the Scottish ones!

Loch Broom were sold out of 10A fast blow they had a great selection but no 10A (hmm wonder why??) 
Drove on to Fort William and yayyy pack of 10 at CEF now safely in the van!
Will attempt the change tomorrow.. what a palava!

How did you get on with this?
I think I have the same problem, everything is fine on gas but I have no functions on ehu, when I try it on 240 the heater just clicks
Thanks karl

Have a read of this Karl.

Hope it helps.

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