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Topic: Truma Combination Boiler W45h error code

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MadFrank

25/3/2016 at 1:13pm
Location: Stratford Warwickshire
Outfit: Eccles 640 - BMW 520D Tourer

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Hi

Has anyone ever suffered with this error code on the LCD panel.

This is one of those new boilers that does the heating and the water in one unit.

The error code points to loss of the 230v supply - suggested remedy according to the manual is to reset the units overheat protection module.

Have tried this to no avail - othere suggestions include swapping a fuse in the unit - but this is protected by one of those tamper evident seals :(

Anybody had this problem and can suggest an easy fix .

The boiler works fine on gas - but I've gone through 2 cylinders in a week....

Thanks in advance.

G7ACU

27/3/2016 at 3:22pm
Location: West Mids
Outfit: Swift Ace Statesman & X-Trail 2.0

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Is there any chance the trip or separate switch for the water heater has been inadvertently knocked off?
My Swift uses a Sargent consumer unit which has several upwards facing push buttons for various circuits; the water heater accidentally got turned off during access to the storage locker, and I had this exact same symptom.

-------------
Paul

Every day's a school day!

MadFrank

27/3/2016 at 6:20pm
Location: Stratford Warwickshire
Outfit: Eccles 640 - BMW 520D Tourer

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Hi - thanks for the reply - the issue was fixed earlier today on another forum. The cause was a blown 230v 10a fuse on the actual Truma unit itself.

James1978

22/1/2017 at 1:14pm
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Afternoon all. Bit of an urgent one as away in 5 days time. Had same fault come up and it isn't due to knocking a switch so can you confirm where abouts the fuse is and how to go about changing? If u have a how to guide if u can send me like it will be greatly appricated.

MadFrank

23/1/2017 at 2:35pm
Location: Stratford Warwickshire
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Hi, there are 2 fues to check.....

The 2 different fuses (12v & 230V) are shown on Page 17 in the hyperlink shown -

https://www.truma.com/downloadcenter/combi_e_cp_plus_ready_operating_de_gb_fr_it_nl_dk_se.pdf

The 12v 10A is the easist to check - the other one (230v 10A) is more difficult to check and involves taking the side panel off the unit. Only do if you are technically competetant.

Ensure that the power in the caravan is completely isolated and that you have disconnected the battery.

My boiler was mounted so that the fuses were mounted in the side facing the wall of the caravan - so i was working blind on touch alone - hence point about TOTAL isolation of power.

If in doubt get someone to do it for you - but if you are moderately technically competent it is easy enough.

Fuses are a little difficult to get hold of - I went to Maplins and they had packs of them for a few pennies.

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MadFrank

23/1/2017 at 2:36pm
Location: Stratford Warwickshire
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Oh and the fault was caused by turnung the boiler om before filling with water......

Stuartww

via mobile 26/4/2019 at 5:10pm
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Had the same fault and thanks to your post, perservered and got there in the end. Only thing I would add for anyone else is that the removal of the side panel is tricky. Remove the two screws at the top and then gradually work the panel in a downwards direction to free it at the bottom. There are only the two screws. The positition of these units means you will probably raid the wife's make up bag for a suitably small mirror so you can see the 230v small fuse.

towedyears

27/4/2019 at 3:21pm
Location: Cannock Chase Staffordshire
Outfit: Lunar ultima 564+Volvo XC60D5 AWD

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I also had the same problem no heat or hot water despite 240volt power. Fault code was 45 tried pressing the reset button and checked the t10ah fuse located under the flip up panel on the boiler but both were ok. The fault was the lower fuse only accessible by removing the side panel held in place by two tork head screws top left and top right then folding panel forward and pressing down to unclip from boiler. This exposed the second lower Printed Circuit Board and the hard to spot the second fuse which had blown. I Ordered 5 fuses yet to be dispatched of Ebay from a caravan accessory shop for £11.00 But then noticed ten fuses for £4.99 free post these arrived within 24 hours and solved the problem. The spare fuse are in the van on stand by

towedyears

27/4/2019 at 4:02pm
Location: Cannock Chase Staffordshire
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Hi Frank I note your comment re fuse blown due to not filling the boiler with water but the instructions for my Truma combi say the electric heating can be used without water. It also says the heating element can overheat and trip out if the unit is not allowed to cool and the water is emptied while still hot. The fuse is an anti surge fuse and others more technically qualified than me have suggested on other forums a weak or aged fuse or sudden power surge could all cause the fuse to blow. I fitted a replacement fuse it has not blown and the boiler now works indicating the element was not defective. The mystery of what is often called electrickery!

ewXXXidd

via mobile 27/10/2019 at 6:48pm
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I've had this fuse blow twice. Once earlier this year, changed fuse and all ran well till this weekend when it blew again. Unfortunately I can't pin point what triggers it..... It seems to happen when both space heating and water heater are on together. Usually have boiler on mix (gas/elec).

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Colicd

via mobile 06/11/2019 at 12:54pm
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I have a new ( April) Carthago and I had this fault. As advice from the dealer there is a fault if unplug the 240v without turning the boiler of it will happen. All I did was press the reset button the first time and it cleared. It then happened a second time, I pressed the reset it didn’t clear but went to do something else, 10 minutes later it had cleared. Apparently there is an update the dealer can do to clear it. Hope this helps.

steve911

01/1/2020 at 9:19am
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Hi all, I have the same issue with my Truma combi 4 which has just blown the 10A fuse. I have done a lot research for this blowing. I have checked all components on the PCB and no defects no dry soldering joints ect: if it was a fault on the board can only think it would be with the R3 blue resistor.
The heater elements megger out all ok
One possible reason is the low voltage coming into the van combined with low startup heater element resistance and aging fuse tolerances.
If we have low voltage of say 210V coming in then with 1800W elements coming on the running current would be 8.6 amps, not taking into account this is the rated wattage and could change with age and tolerance. Then we have the start up current which can be very high when the elements are cold.
Tried to find the rating the fuse would blow at but unable to find data sheet on this.
Looking at the PCB R3 big blue disc in picture looks like a CL-140 Inrush Current Limiter which if already hot will not prevent inrush current. Used these before on valve amps for the heater circuit to reduce inrush current.
So my theory is the inrush current on close tolerant design with cold elements, ageing elements & fuse would be the cause of the fuse blowing.
We have a number of these on our trains electronics which I work on and they do blow for no faulty reason.
Sad thing is the access to this fuse was poorly designed. I have herd someone say this was a EU reason to stop easy access which I have never come across before.
Running with no water will not cause this as it is designed to run with no water.
Dirty plug which one dealer mentioned will play some part if it is reducing input voltage, along with 25 m cable would up on the floor but I expect this is not the sole reason, site voltage low will also have to be apart.

For me I will replace the fuse and in future only switch on heater one element at a time from control panel which will drastically reduce the inrush current.

PennyBenimar

31/3/2020 at 1:40pm
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I have this problem on my Benimar. Is there a low risk way of confirming the 230V fuse on the Combi has actually blown?

I have noted that when the “W 45 H” error shows on the Combi Trauma control panel a red light on the Combi flashes a morse code of ..-.--.- (EAAK). Have contacted Combi, but no reply from them.

Have checked the power fuses on the van, which are all OK. I've tried the overheating protection reset. The button doesn't seem to press very far, and doesn't fix the problem. Looks like I might need to replace 230 V fuse, hence my question.

Ancient Uncle

31/3/2020 at 2:30pm
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Hi Steve911
Just wondering where you are as you appear to writing to us from the future. Have you discovered time travel? Your posting above is dated 9:19am on 01-04-2020.

blueexpo97

31/3/2020 at 4:43pm
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01/1/20

-------------
XVI yes?

As well is two words!
How does a sage know everything about everything? or does he? or does he just think he does?
Remember, if you buy something you bought it, not brought it.

navver

31/3/2020 at 7:57pm
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I wonder if it's caused by running boiler on gas and electric. Fuses blow because they get too hot. Running on gas will raise the ambient temperature where the fuse is located. Passing 8.5Amps through it in that temperature may be too much.

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