Truma Therme, the answer to our prayers if we have blown air

[ScoTTyBEEE]

After many hours or searching for calorifiers and all sorts of methods to heat hot water I've finally found the perfect device for those of us with blown air heaters. The Truma Therme sits inside the heating duct and provides hot water, and includes a 300w immersion for summertime solar use. I can't begin to explain how happy I am to have found this.

Truma Therme - Inform now

The Truma Therme for caravans heats water with existing warmth from the heater or with a 230V electric heating element. Find out more.

www.truma.com

 

[wildebus]

After many hours or searching for calorifiers and all sorts of methods to heat hot water I've finally found the perfect device for those of us with blown air heaters. The Truma Therme sits inside the heating duct and provides hot water, and includes a 300w immersion for summertime solar use. I can't begin to explain how happy I am to have found this.

Truma Therme - Inform now

The Truma Therme for caravans heats water with existing warmth from the heater or with a 230V electric heating element. Find out more.

www.truma.com

That is one of those products that make you wonder why it is not better known! I recall seeing lots of discussions in the past on various forums about rigging up something just like that truma unit but no mention of a ready-to-fit solution. Sounds very good.

On a similar note, I see they have this water heater as well ... https://www.truma.com/uk/en/products/truma-water-systems/truma-electric-water-heater-boiler.html - that looks dead handy. I never saw that before I fitted my electric water heater

Have you a price list or supplier info yet?

 

[Millie Master]

I faced a similar dilemma when planning the interior of 'Millie', eventually with my budget in mind I started searching relentlessly on all the various on-line sale sites and eventually I bought a brand new, still boxed but second hand Henry gas/electric water heater for less than £100 on Gumtree and 4 heavy usage years later I am still over the moon about my purchase!

 

[ScoTTyBEEE]

They're £150 from rainbow conversions. The only downside I can see is they need to be run in an un-pressurised system, so micro switch taps and submersible pump. Not sure that's a huge problem, need to thing about it. It's either this or installing gas just to get hot water, which I was reluctant to do.

Do you find you can use an electric water heater over winter @wildebus? This is my problem, I'll have 6-900w of solar so summertime won't be an issue but winter, different story.

 

[wildebus]

They're £150 from rainbow conversions. The only downside I can see is they need to be run in an un-pressurised system, so micro switch taps and submersible pump. Not sure that's a huge problem, need to thing about it. It's either this or installing gas just to get hot water, which I was reluctant to do.

Do you find you can use an electric water heater over winter @wildebus? This is my problem, I'll have 6-900w of solar so summertime won't be an issue but winter, different story.

I had a search after I asked the question and I actually saw them for £130 inc VAT (might be worth a quick search if buying?). Good value I think even at £150. The only thing which is a slight shame is that the element is 240V AC. Would be brilliant if it were (even as an option) to have a DC element as could use off-grid without needing to have an inverter.

The heater takes longer to get up to temp in the winter of course as the starting temperature of the water is quite a bit lower but yes, still very usable if you plan ahead i.e. "well, I will use the heater as will be driving later on" kind of thing.
I am lucky as I do have a big battery bank so heating 10L of water doesn't actually use a big proportion of the battery capacity (my hot water is for washing up, washing face and a "bucket wash" rather than a shower so my hot water needs are pretty small.

 

[MarkJ]

Maybe it's just my setup, but I'd be surprised if the hot air coming out of my Combi 6 would make much of a fist at heating up water.... It's nice to feel it on your toes in the morning but it'd take an age to get any volume of water hot, I would have thought.

 

[MarkJ]

They're £150 from rainbow conversions. The only downside I can see is they need to be run in an un-pressurised system, so micro switch taps and submersible pump. Not sure that's a huge problem, need to thing about it. It's either this or installing gas just to get hot water, which I was reluctant to do.

Do you find you can use an electric water heater over winter @wildebus? This is my problem, I'll have 6-900w of solar so summertime won't be an issue but winter, different story.

Yes, agree - made me reluctantly think about gas again

 

[Squiffy]

Just as an aside to this the Truma combi 4/6 heats the water regardless when on room heating and you only have to switch to heating water if you are not heating the van interior, so in blown hot air mode it is very economical as its providing hot water too, but to be frank it does not use much gas in water heating mode either as the thermostat controls your water temperature 40 or 60 deg. This also applies if hooked up to shore power and using 240V. Phil

 

[MarkJ]

Just as an aside to this the Truma combi 4/6 heats the water regardless when on room heating and you only have to switch to heating water if you are not heating the van interior, so in blown hot air mode it is very economical as its providing hot water too, but to be frank it does not use much gas in water heating mode either as the thermostat controls your water temperature 40 or 60 deg. This also applies if hooked up to shore power and using 240V. Phil

Yes, but we find it a bit frustrating. We only need hot water once or maybe twice a day, but having to heat it means less energy goes into room heating when you want a quick blast. Overnight it’s good - you have a kind of storage heater under one of the seats.

In my lovely, shiny, perfect new van (ho ho) I’m thinking to separate the two functions, and hopefully save space too (the Truma is big). Truma VarioHeat for space heating (really compact and hopefully quieter than a Propex) and Whale Expanse, mounted underneath, for water.

We’ll see. Some days it looks easy, other days it seems impossible!

 

[Squiffy]

Yes, but we find it a bit frustrating. We only need hot water once or maybe twice a day, but having to heat it means less energy goes into room heating when you want a quick blast. Overnight it’s good - you have a kind of storage heater under one of the seats.

In my lovely, shiny, perfect new van (ho ho) I’m thinking to separate the two functions, and hopefully save space too (the Truma is big). Truma VarioHeat for space heating (really compact and hopefully quieter than a Propex) and Whale Expanse, mounted underneath, for water.

We’ll see. Some days it looks easy, other days it seems impossible!

With all respect Mark only the initial heating of the water takes a minimal amount of calories from the blown air process as the heating of the water is a secondary part of the operation, and once the water is up to heat all the calorific goes into the blown air side of it and the water unless you draw from the hot tap stays well above the 40 deg cut off point. I have to say that regardless of weather outside even in -0 conditions my van at least, gets far too cosy in a very short period of time to the point of having to lower the room thermostat setting, I have never had to use the boost setting other than occasional tests to make sure all is working. . Phil

 

[SquirrellCook]

thermostat controls your water temperature 40 or 60 deg.

Is this hot enough to ward off legionars disease?

 

[Squiffy]

Is this hot enough to ward off legionars disease?

40 deg is where you could be vulnerable to legionnaires, but the conditions for it have to be present in the first place, 60deg is safe. Phil

 

[MarkJ]

With all respect Mark only the initial heating of the water takes a minimal amount of calories from the blown air process as the heating of the water is a secondary part of the operation, and once the water is up to heat all the calorific goes into the blown air side of it and the water unless you draw from the hot tap stays well above the 40 deg cut off point. I have to say that regardless of weather outside even in -0 conditions my van at least, gets far too cosy in a very short period of time to the point of having to lower the room thermostat setting, I have never had to use the boost setting other than occasional tests to make sure all is working. . Phil

No offence at all! I'd wondered about our installation... if we do not have the hot water heating on, just the hot air, it takes ages (over an hour) for any significant water temperature to be reached. And certainly for the first 15-20 minutes (when you're at your coldest from being outside) our experience is that the blown air temp is a bit feeble. I talked to the dealer about this when we first had the van, and he just said the new installations weren't as good as old ones. Never got to the bottom of what he meant! We only have two or max 3 vents open as well, so it's not as if we're heating up the garage.

 

[Squiffy]

No offence at all! I'd wondered about our installation... if we do not have the hot water heating on, just the hot air, it takes ages (over an hour) for any significant water temperature to be reached. And certainly for the first 15-20 minutes (when you're at your coldest from being outside) our experience is that the blown air temp is a bit feeble. I talked to the dealer about this when we first had the van, and he just said the new installations weren't as good as old ones. Never got to the bottom of what he meant! We only have two or max 3 vents open as well, so it's not as if we're heating up the garage.

Have you checked the duct connections to the heater and made sure they are fully home as there can be a significant lose of pressure if they are not pushed fully home, I had a problem like that with two of my ducts, must have happened whilst I was delving around under the bed at some stage it looked as though everything was all up tight until one day my wife mentioned that the draft from the duct outlets were not as strong as they used to be. I found that it only needed one duct not to be connected properly to affect all the outlets and if yours is a 6 then it would be a lot worse, it would definitely be worth checking for a leak in the air system as on full blow mine would fly a kite. Phil

 

[MarkJ]

Have you checked the duct connections to the heater and made sure they are fully home as there can be a significant lose of pressure if they are not pushed fully home, I had a problem like that with two of my ducts, must have happened whilst I was delving around under the bed at some stage it looked as though everything was all up tight until one day my wife mentioned that the draft from the duct outlets were not as strong as they used to be. I found that it only needed one duct not to be connected properly to affect all the outlets and if yours is a 6 then it would be a lot worse, it would definitely be worth checking for a leak in the air system as on full blow mine would fly a kite. Phil

Really? No, I haven’t checked so that’s a good shout. Especially as now I come to think of it, I did notice that shutting a couple of vents seemed to make little difference to the ones we sit near, which is consistent with a leak somewhere! Thank you! Why didn’t I think of that...