# Truma elctric collar retrofit?



## kijana (May 1, 2005)

Our '98 Dethleffs is fitted with a Truma C3402 gas powered boiler/heater.

It's very annoying to sit on sites with free electric and have to use gas to heat water.

Has anyone retrofitted the electric water heating collar to this type of boiler?

Any problems/tips? Where did you buy the collar?

Many thanks

Bruce


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## rayc (Jun 3, 2008)

Hi, go to the forum main page and enter truma collar into the search box with the motorhomefacts.com box checked.

The concensus seems to be do your sums, you can buy a lot of gas for the cost of the collar.

Note that the collar only gives you hot water not heating [I know you only wanted hot water]. To get heating as well you will have to change the boiler which is mega bucks.


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## rayc (Jun 3, 2008)

a post from frank311 in the archives that may assist you:
"
The Part Number for Truma's 230V heating-collar retrofit fit kit for a Series 2 Trumatic-C combination air/water heating appliance (which I assume is what's fitted to your Hymer B694) is 34141-01 and the catalogue (01/08/2007 issue) price was £204.59 (VAT Inc.) 

The heating-collar draws just 450W of 230V mains power, so is pretty slow heating water from cold. Conversely, this low 2A power consumption means that virtually any campsite 230V hook-up can be employed. Where the campsite hook-up is essentially 'free', there will be the temptation to leave the heating-collar on continuously so that hot water is constantly available. Whether the collar will tolerate such treatment over extended periods is slightly questionable though, and I know of one instance where a heating-collar failed (a collar cannot be repaired) and the motorhome dealer cited constant use as the cause. 

Fitting the collar to a Trumatic-C is easy and quick enough in principle - in practice, it can be an absolute pig. It all depends on how accessible the Truma appliance is, but (generally speaking) adding the collar will require the appliance to be removed from wherever it is installed in the motorhome. The more inaccessible the heater (and Hymer has a reputation for shoe-horning Trumatic-C heaters into very constricted spaces!), the more costly the labour-charges will be for fitting the collar. And, of course, there will also be a need to install supplementary 230V wiring to power the heating-collar. 

It's worth repeating what Russell has already advised - that there's no means of converting a gas-only Trumatic-C appliance (C-3402/C-4002/C-6002) to provide 230V AIR-heating: the best that can be done is retro-fit the 230V WATER-heating collar. 

There is a Trumatic-C variant (the C-6002EH) that can provide air and/or water heating via gas and/or 230V, but the design of this appliance differs significantly from gas-only Trumatic-Cs and you can't convert the latter into the former. 

The latest Truma combination air/water heaters are gas-only (Combi-4 and Combi-6) or gas/230V (Combi-4E or Combi-6E), with the latter offering similar capabilities to those of the C-6002EH. Once again, it's not practical to convert a gas-only Combi into its "E" version. (For what it's worth, there's also a recently-introduced diesel-fuelled Truma Combi-D.) 

When considering the economics of whether or not to have a 230V heating-collar fitted to your Hymer, you may wish to bear in mind that a Trumatic-C appliance uses about 170g/h of gas in water-only heating mode. My experience of these appliances is that it will take roughly 40 minutes to heat the appliance's 12 litres of water to 60°C using gas, which would equate to a gas usage of about 100g per 'water-heating'. If your Hymer's LPG tanks have 80 litres capacity, that's around 40kg of gas. As you'll be getting about 10 individual water-heatings per kg of gas, that means your gas reservoirs, when full, should be able to provide some 400 separate water-heatings. You'll have do your own calculations as to how many days usage this"


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## b16duv (Feb 14, 2006)

*truma heating collar*

Hi,

I got mine from truma's main distributor at the Birmingham show 2 years ago. After a bit of haggling it was £125 for the kit.

You need to remove the cardboard cover from round the tank in order to fit the collar. We managed just by loosening the cardboard and feeding the collar round.

You will need a fused 240volt power supply from the main power board and a suitable place to put the control unit and run the wiring loom to the collar.

In all, it's about a two hour job providing you can access the heater relatively easily. Mine is in the cupboard below the fridge and was only accessible from the front.

As with all toys for the motorhome, return on investment is seldom the number 1 priority (there are much cheaper ways to holiday!) so the trade off for me was convenience versus price. It gives me a secondary method of getting hot water if necessary.

David


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## kijana (May 1, 2005)

Thanks to both Ray & David for their replies. I must try harder on the search facility - I usually have trouble getting past the first few posts with this.

Anyway, I now have more info on the collar to think about, so thanks chaps.

Apologies for late reply - this is due to a both intermittent wifi on this campsite plus Christmassy things taking up time otherwise available for surfing.

Cheers

Bruce


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## Jezport (Jun 19, 2008)

How about fitting one of these after the boiler Truma Therme

What are your thoughts on this unit? It would also be handy if you have a diesel blown air system as it will heat the water from hot air also.


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## kijana (May 1, 2005)

Thanks, Jezport - that's a really useful website.

Interesting idea, fitting a heater unit downstream. I don't have diesel air heating, but would still consider the separate heater solution.

Pros I guess are low cost and possibly easier fitting (if the boiler had to come out to fit a collar I'd prolly bottle it!!)

Cons are space - not a big unit but still more space needed than a retrofitted collar. And possibly potential for leaks, as I'd have to plumb it in to the hot water system downstream of the boiler, and more joints = more potential leak points.

Good option though. Now I've got even more to think about. . .

Bruce


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## 2escapees (Nov 28, 2008)

I had my collar fitted by Truma in Munich and at the same time they fitted an electric timer for the gas. So either way we wake up to hot water and a warm van. It is well worth the investment.


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## Jezport (Jun 19, 2008)

kijana said:


> Thanks, Jezport - that's a really useful website.
> 
> Interesting idea, fitting a heater unit downstream. I don't have diesel air heating, but would still consider the separate heater solution.
> 
> ...


Just had a look at their fitting instructions, one thing it says is that it should not run at more than 1.2bar or a regulator should be fitted. I am not sure what pressure most pumps run at.


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## Bob45 (Jan 22, 2007)

I had one fitted by Peter Hambilton and would recommend it. It heats the water up quickly and obviouslt takes advantage of the EHU for which we have already paid. We leave on all the time as it has a thermostat.
Bob45


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## androidGB (May 26, 2005)

Bob45 said:


> I had one fitted by Peter Hambilton and would recommend it. It heats the water up quickly and obviouslt takes advantage of the EHU for which we have already paid. We leave on all the time as it has a thermostat.
> Bob45


SNAP, would also echo the comment regarding cost effectiveness versus convenience.

We also have the timer for the heating and consider both money well spent

Andrew


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## Rapide561 (Oct 1, 2005)

*Timer*

Hi

What was the price of the heating timer including fitting, please?

Russell


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## androidGB (May 26, 2005)

*Re: Timer*



Rapide561 said:


> Hi
> 
> What was the price of the heating timer including fitting, please?
> 
> Russell


Hi Russell,

Just under £300 incl VAT.

Some might find this expensive, but I can't sleep with any form of heating on and like a good supply of fresh air. I don't however like getting up to a freezing van, so have the heating coming on an hour or so before we get up

Andrew


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