Truma Ultrastore water heater insulation.

The water heater in my van is beneath a panel in the wardrobe. When the water heater is on, either by gas or electric if on EHU, the base panel, and thus the whole wardrobe, gets very warm. Nice on a cold morning, but not pleasant in southern climes when we're doing everything we can to keep cool..
Recently I removed the base panel, no easy task with electric wire trunking in the way, and I see the water heater is just like a big stainless steel kettle, no insulation at all. Can anyone see a problem with fitting an insulated jacket around it, and has anyone done it? I imagine it would also save on gas/electricity as well.
Al.

I've never opened any of mine up but always assumed there was insulation between the plastic outer case and the boiler itself. Did you perchance take any photos as you took it apart?

Peter

Closed up at the moment Peter, but I'll take a few pics when I next remove the panel, I've altered it slightly so it'll come off easier next time. But last time I took off the flimsy plastic lid it seemed there was nothing between the thin plastic casing and the stainless boiler. My plan was to remove as much of the plastic casing as possible and fit a hot tank type insulated jacket.
Al.

Hi Al,
Last year, I had the transformer go on the pcb at the back of the Ultraheat, so I had to strip out the drawer and the fan unit to get down to it.

Like you, I had noticed the seemingly excessive amount of heat that escaped from the Ultrastore, so while I had access, I wrapped the thing up in some mineral wool I had left over from the extra loft insulation I installed. This included a full wall to wall layer over the top.

The unit has gone right through all of our winter travels without any problems and now that we are not using the Ultraheat we can tell that the bottom of the wardrobe is noticeably cooler. Also, after being on hook-up overnight, we have warm water for our stops on the road during the day - a bonus that I hadn't considered at the time.

Derek

Has anyone any further suggestions to add please?

Our van is a 2015 Nuevo and like those mentioned above, you could almost use the drawer under the wardrobe as a slow cooker!!

It is the Truma Combi 6 boiler, and having removed the drawer there's nothing at all covering it. It would be fiddly, but I could do a fairly decent job of covering the boiler through the drawer orifice.

Any further advice would be much appreciated. You can't beat first hand experience!!

Dave

Sounds like a great idea as my wardrobe gets very warm even more so when the fire is lit. Look forward to see some photos with the lid off the hot water tank.

I had some offcuts of loft insulation spare and carefully located it around the hot water tank and the rear of the Ultraheat unit.
As Al and Derek have said it does make a difference to the heat loss from the Ultrastore water heater .
My hot water is still warm the next morning, enough to have a wash at the sink.
Boaby

Thanks Boaby

I think I have some of that too. We live quite close to Willersey though, so I may wander across one day and scrounge some of their bespoke stuff. If it's the same as they used on previous vans it's very soft and flexible (and quite fragile) so it should be ideal for dropping down the back and draping in close contact over the boiler.

I also like the idea of Derek's "wall to wall" layer over the top.

Will report back of course if I come up with anything helpful.

Dave


P.S. On second thoughts I'll stick with the loft insulation. If I had to remove that fluffy cotton wool stuff that A/S use it would probably fall apart and be difficult to get out from behind the boiler. Loft insulation is pretty durable and would stand some gentle tugging.

The "wall to wall" layer should be easy. A thin length of batten screwed to the wall on each side, with a few narrow cross pieces to support the insulation. Again with easy removal in mind.

Dave
I have a piece of offcut loft insulation that fits into the Thetford cassette void, i stuff it in during the winter when we are not using the van,  the cassette is in the garage.
Maybe going overboard. but it gets cold inside the wee cabinet.
Boaby

Thanks again Boaby.

Overboard or not, every little helps!! 

I think I'll have a little fiddle under the wardrobe tomorrow. There are a lot of ducts and pipes in the way so it won't be a perfect job, but I don't think there's any insulation built into the boiler. If I press the plastic cover it goes in about 2 or 3mm and seems to hit metal - presumably the boiler itself. If that is the case it's no wonder the wardrobe gets hot, as a tiny little air gap like that would be virtually useless as an insulator.

Dave


P.S. I presume "the wee cabinet" was deliberate. Very droll!

I don't know a lot about the mechanics of the thing but I've always thought of Truma as a pretty on-the-ball firm. Surely if insulation were a good thing then they would have put it in in the first place ?  It's hardly going to add significantly to the costs of an already very expensive item.

Our experience of them is that they are always willing to answer questions, give advice etc on the phone or at the factory. Would it not be a good idea to find out first why they heater is not insulated and if there is a reason why it should not be retro-insulated ?

Just a thought....

A very good thought Quilter.

I rang Autosleepers today to ask just that question, but haven't had a reply yet. Earlier boilers were definitely lagged, but I've no experience of the Combi 6.

A call to Messrs Truma tomorrow I think.

Thanks

Dave

Just rang Truma and spoke to a young lady who sounded quite knowledgeable.

She warned against putting insulation on or around the boiler itself as it might cause it to overheat. Does that sound right to you??

I would have thought the more heat kept from escaping the better. Surely the thermostat will ensure that the boiler doesn't overheat, whether it is well insulated or (in this case) obviously not! That's precisely what it's there for!!

Obviously if the air intake to the heater blower was restricted or blocked off it could cause serious problems, but putting additional insulation round the outer casing of the boiler could only be a good thing - couldn't it?

What do others think?

Dave

This does make sense to me. We don't know what the thermostat is set for but, presumably, it is set for a temperature that would not include the extra insulation. Put the extra insulation into the boiler cavity and the boiler might switch off before the temperature of the water reaches 60 deg C ( which, I understand, is the temperature it must be run at to avoid possible Legionella infections.)

I was more concerned that stuffing insulation into the cupboard itself might prevent the heater vent fan from doing it's job. On the other hand, in our previous van, where the heater was in an underbed storage space, there were no instructions to avoid packing the rest of the storage space with as much as you could get in. 

We did have problems, all the life of that vehicle, with burning smells from the boiler and this is the same in our current 18 month old Broadway, where the boiler sits in an otherwise empty space.

I have to disagree Quilter - but I'm always ready to be shot down if I'm talking rubbish!!

As I understand the workings of a thermostat, it will simply switch off the power when the water temperature reaches the value it is set to - in this case 60 deg C. (Or 40 deg if you choose that option.)

I don't think the degree of insulation would make any difference. The thermostat would operate as soon as the water reached the desired temperature whether the tank was "polar" insulated, or not at all.

Interesting discussion, this is!

Dave

Dave,
I can confirm that, another six months down the line, nothing terrible has happened to our heater.

By the way, my 'wall to wall' was a full width piece of insulation after I had stuffed all the hollows and spaces with torn off bits of rockwool. It just lies flat on the top and tucks under the fan unit. This was also helped by the fact that I had previously lowered the water pump quite considerably to allow an expansion tank to tee off upwards. There's no battens or anything.

Hope this helps,

Derek

Thanks Derek

It does help a lot. I think our Combi 6 unit is different to yours, but the principle will be the same. I may need a couple of battens, but your idea of the "wall to wall" thermal barrier may be enough to alleviate the problem, and will be fairly easy to do.

If it's not enough I can always add more insulation to the boiler itself - which will be a bit more awkward working through the drawer orifice. Yet another economy measure from Messrs Autosleepers is the lack of a removable inspection panel in the base of the wardrobe.

Dave

I agree Dave, I can't see any problem with adding more insulation round the water heater. Domestic storage tanks come with bonded jackets, but it does no harm to add more. But as has been said, care has to be taken that it doesn't get in the way of any other gubbins under the wardrobe floor. In my case this includes the back of the space heater and battery charger.
My model of van doesn't have the drawer, but the floor is removable. As I said at the start, this is a pain to remove first time due to items being added above it during manufacture, but with a little modification to the panel, removing it now only takes a few minutes.
Regarding the advice from Truma, I'm inclined to say, well they would say that wouldn't they. I've yet to hear of a manufacturer of anything who would endorse DIY modifications to their product. They always have an eye out for lawsuits.

Thanks Derek...

Dave...AS remove the panel under the drawer to get at the heater, if evidence when ours came back from having a new heater is to be believed. It would possibly need new screw covers afterwards but they must be available.

One thing I would do is wrap and seal the insulation used to stuff the hole. Both dealer, Truma and AS always attribute the ghastly smell we get from our heater ( and used to have in the last van) to dust on the elements. My housekeeping standards are not high but I don't think it is dust. I would not like to risk the fibres from the hot insulation being sucked into the heater.  We also have a inlet vent on the front of the wardrobe, below the drawer, to pull air in from the van. Don't block it- I'm sure you wouldn't !

Whatever the views of Truma I still would not insulate inside the boiler casing itself. As I said earlier, if it was a good thing to do then I am sure it would have been done at manufacture. Ten pence worth of insulation would have made no difference to the cost of the boiler.

When our boiler was changed from a Combi 4 to a Combi 6 ( don't ask !) a new outlet duct was added, in the bed base close to the cab seats. The new heater, producing more heat than the old, needed the extra vent to prevent overheating.

More very useful comments - thanks again both.

As I said last night, I think it's going to be Derek's "wall to wall" for a start, and see how that goes. I begin to think a 3" or 4" thick slab of foam rubber from Dunelm might be the easiest, as it's fairly rigid and self supporting and has no fibres to release. (It has to be fire retardant these days, so it will be no more flammable than the rest of the van!!)

Dave

Gromit wrote:More very useful comments - thanks again both.

As I said last night, I think it's going to be Derek's "wall to wall" for a start, and see how that goes. I begin to think a 3" or 4" thick slab of foam rubber from Dunelm might be the easiest, as it's fairly rigid and self supporting and has no fibres to release. (It has to be fire retardant these days, so it will be no more flammable than the rest of the van!!)

Dave

Will it smell when hot Dave ? Or even melt ?

In our last van the top of the heater ( Combi4) was not secured properly. On our first trip out the bed struts above it charred and the plastic storage box next to it melted along one side.

I had a look at the latest Combi when at the NEC and no there is no insulation at all. Seems crazy to me and as ours is under the bunk the heat into the bed is extremely uncomfortable. Truma man could not say why they didn't insulate it .
I put some insulation around the heater bar the electrical control gizmo but hasn't helped much. I also pack the bedding against the air outlet end but the heat still leaches through into the seat base/mattress. I will now pack some more insulation around the 'tank'area and the plenum at the ducting end and see if it improves things a bit.

Quilter wrote:Will it smell when hot Dave ? Or even melt ?

In our last van the top of the heater ( Combi4) was not secured properly. On our first trip out the bed struts above it charred and the plastic storage box next to it melted along one side.

That theory didn't last long then!

I'm amazed that the heater could get as hot as that, but many thanks for the warning. The foam would have been several inches clear of the top of the heater, but after hearing of your experience it just isn't an option any longer. Back to the drawing board!

Dave

Gromit wrote:

I'm amazed that the heater could get as hot as that, but many thanks for the warning. 
Dave

That was with a faulty top however Dave. It hadn't been properly secured and was higher than it should have been so was touching the bed struts. It wasn't touching the plastic boxes though...

After that we put a piece of silvered reflective radiator foil under the bed struts, above the boiler. This needed renewing on a regular basis as the foam backing used to go crisp.

Ours does not get anywhere near as hot as that