Calorifier system

[Nabsim]

I know at least one person on here is running a calorifier for hot water so would like to pick their brains.

I have a Sprinter based coachbuilt that has been changed quite a bit from original by previous owner(S). The hot water is produced by the engine coolant going through a single coil calorifier. They had the system professionally installed and spent a wad on it, if I keep moving I have constant hot water no problem at all.

I like to park up out the way though and stay a while if i like it though. There is a 5kw Hydronic built in that heats the engine coolant when ignition is switched on but only with ignition. I want to change this at some point so I can run it independently but so far haven’t got a good enough understanding to snip wires. The USA Sprinter forums are somewhat contradictory on how best to do it.

I like the look of these combined air/water heaters from China and thought they may be a good back up system for both my D4 and Hydronic. So that’s the layout and reason now the question.

can I tee into the exiting Coolant pipes to add another heat source or would I need to change to a twin coil calorifier? The later would mean at least double the cost which won’t be happening. If tee in is okay would I need to add an additional pump, I presume so, and would anything else be required.

A kettle is fine for me but when Mrs is with me she likes running hot water. The calorifier is currently fitted with a 1Kw immersion but never been wired in and too big for my 1Kw genny I expect. I did get a 300w 12v immersion I was going to fit to use excess solar but as solar is doing nothing really since around September this year I don’t think it worth doing.

 

[SquirrellCook]

You should have most of what you need without spending much more. First thing 500W 240v element for the calorifier, you can you use a small generator without getting a hammering.
I've seen many circuit diagrams of how to install this stuff, most seem overcomplicated. I'm convinced Mine is wrong, but it works and works well.
The hardest problem I've had is knowing for sure which way the water is flowing.
Are you wanting to use the leisure battery to power the heater? I use the engine start on mine for no other reason as it was easy at the time.
If changing the plumbing you must ensure the heater never feeds a closed loop or you will over heat the heater.
An easy way to think about the plumbing is to think about a ladder. Each rung is either a heater of radiator. The engine is also a heater.
By putting a valve in the right place you can isolate an item.

 

[Nabsim]

With the existing Hydronic I just need to get stuck in really and see what happens. I have it in the back of my mind if I substitute a permanent (or switched) live for the d+ it should work as is off the starter battery. Probably isn’t going to be that simple though lol

500w element is probably a good idea as I could be using that now

if/when I add an additional combined air/water heater it will be powered from the leisure battery’s. I don’t mind if it runs round the engine block or not although I appreciate it would need to run longer and use more fuel doing that. It was more how two systems would sit together, the existing has an electric water pump that comes on with it, would pumps need to be powered on no matter which heater runs, stuff like that?

 

[SquirrellCook]

I think your hydronic 5 would be more than enough for all your water heating needs. Yes the water does need to be circulated all the time. Without knowing more about your setup I can't comment. Though crudely the heater needs a power supply, this is normally fused. Then it needs a start signal. This is normally carried out by a small controller module, some can do more than others. If you found someone who has one and understands how it works, they could give you a better insight in person. With your water taken care of, an air heater would be better on fuel and electric.

 

[wildebus]

You should have most of what you need without spending much more. First thing 500W 240v element for the calorifier, you can you use a small generator without getting a hammering.
I've seen many circuit diagrams of how to install this stuff, most seem overcomplicated. I'm convinced Mine is wrong, but it works and works well.
The hardest problem I've had is knowing for sure which way the water is flowing.
Are you wanting to use the leisure battery to power the heater? I use the engine start on mine for no other reason as it was easy at the time.
If changing the plumbing you must ensure the heater never feeds a closed loop or you will over heat the heater.
An easy way to think about the plumbing is to think about a ladder. Each rung is either a heater of radiator. The engine is also a heater.
By putting a valve in the right place you can isolate an item.

Something I have not quite got worked out in my head is this ....

Engine Pre-heaters use a diesel heater to warm up the coolant so the engine gets upto temperature faster.
But for the coolant to flow you need the water pump running presumably? And the water pumps are mechanically driven usually.
So for an Engine Pre-heater to work, you have to start the engine?

If you want to use an engine pre-heater as a 'parking' heater for air or water, you would need to add in an electric pump and bypass the engine coolant system as well as if the engine water pump was not running, then no coolant could circulate?

This is my understanding and don't know if it is right or not?

I know my VW T5 had an engine pre-heater that basically never really worked so not sure on that side, but a lot of folk with those Heaters (Webasto ThermoTops) looked into repurposing as Parking Heaters; plus my T5 had a rear-mounted HVAC system that was powered by a feed+return coolant pipe set that ran from the engine to the rear of the vehicle - and when I turned on the rear heating the engine temp dropped about 20C and the cabin heater never got hot enough (I gave up using the HVAC after that! )

 

[SquirrellCook]

Yes Dave the heater needs to pump the coolant. This pump is normally combined with the heater. Sometimes it’s required to use a second or more pumps if your system is restrictive. There are many ways of plumbing these depending on what you are looking for. I use mine for engine preheating, demisting the windscreen. Boosting the habitation heating and heating the Calorifier. The Engine can also heat the habitation and water whilst in motion. Understanding the flow and balancing the system can be fun though.

 

[Nabsim]

There are two (maybe more) ways they are done I think Dave. One is a pre-heat that can be switched on and used to warm the engine block and defrost/warm cab before you start the engine. This one has an electric water pump that runs when you turn the heater on. You can get fancy controllers with this type, even 7 day timers.

Then mine is used to warm the engine up more quickly reducing engine wear I believe, this doesn’t start until the ignition is turned on.

That’s where it gets a bit cloudy as mine has the electric pump and seems to be most of the way to running with ignition off. I don’t need to start the engine just turn ignition on but leaving it in that position is not a good idea without running the engine.

Apart from that I also have a switch on the dash that runs an Eberspacher heat exchanger that will blow air out of a separate set of ducting. If engine is warm it blows warm air so you can heat the rear while travelling but also in summer you can run cool air if it’s hot.

Finally I also have the REST function on the dash controls. When I pull up and turn the engine off I can continue to use the hot air blower from the engine. This is on a timer but can’t remember how long it runs for without reading manual.

Someone went to a fair bit of expense to change all this over and it really is a great setup if you move each day, just a pity they didn’t have it set to run independently.

saying that Mercedes do sell a kit to change it to independent operation but last price I saw for the kit was £714. It needs a Dave to look at it

 

[Nabsim]

Yes Dave the heater needs to pump the coolant. This pump is normally combined with the heater. Sometimes it’s required to use a second or more pumps if your system is restrictive. There are many ways of plumbing these depending on what you are looking for. I use mine for engine preheating, demisting the windscreen. Boosting the habitation heating and heating the Calorifier. The Engine can also heat the habitation and water whilst in motion. Understanding the flow and balancing the system can be fun though.

When I bought the van I took son in law with me to drive my car back while I drove the van from London to Derbyshire. We stopped at first services on the M1 for some breakfast and I was showing him round the van.

Driving back through the snow I was starting to get convinced I had an engine problem as it was roasting in the van, I ended up driving with both front windows down and kept checking temperature but couldn’t see anything wrong.

It was only after I had parked it up I could hear something running and then discovered one of us had switched the airtronic on. We were both sat round reading manuals trying to find out what controlled it and how to turn it of lol.

Apart from the Eber 810 controller I have an additional switch on the dash which lets you turn it on and off from the drivers seat. You need to use the 810 to adjust temperature or just run the blower without heating though

 

[SquirrellCook]

If you mean having the ignition on is the first click of the key. That should not do any harm. If you are worried about the battery, fit a BMV.

 

[wildebus]

There are two (maybe more) ways they are done I think Dave. One is a pre-heat that can be switched on and used to warm the engine block and defrost/warm cab before you start the engine. This one has an electric water pump that runs when you turn the heater on. You can get fancy controllers with this type, even 7 day timers.

Then mine is used to warm the engine up more quickly reducing engine wear I believe, this doesn’t start until the ignition is turned on.

That’s where it gets a bit cloudy as mine has the electric pump and seems to be most of the way to running with ignition off. I don’t need to start the engine just turn ignition on but leaving it in that position is not a good idea without running the engine.

Apart from that I also have a switch on the dash that runs an Eberspacher heat exchanger that will blow air out of a separate set of ducting. If engine is warm it blows warm air so you can heat the rear while travelling but also in summer you can run cool air if it’s hot.

Finally I also have the REST function on the dash controls. When I pull up and turn the engine off I can continue to use the hot air blower from the engine. This is on a timer but can’t remember how long it runs for without reading manual.

Someone went to a fair bit of expense to change all this over and it really is a great setup if you move each day, just a pity they didn’t have it set to run independently.

saying that Mercedes do sell a kit to change it to independent operation but last price I saw for the kit was £714. It needs a Dave to look at it

There are kits to convert the Webasto TTC Pre-Heater in the VW to a Parking Heater as well, but the cost of those was not far off buying a brand new independant heater (£714 would be more than that!). I vaguely contemplated it but I had a Eberspacher D2 'in stock' so fitted that instead as the Webasto was already 7 years old and could fail at any time potentially (and it did! started running constantly by itself without any reference to low temp or ignition on. VW wanted hundreds to investigate. In the end I just pulled a fuse to disable it as it was not really that important to have anyway)

 

[Nabsim]

If you mean having the ignition on is the first click of the key. That should not do any harm. If you are worried about the battery, fit a BMV.

You turn the key to the position where all the idiot lights come on. Not worried about starter battery as it wouldn’t be constant use and I have alternative methods of starting if needs be

 

[ScoTTyBEEE]

I looked into setting a thermotop onto a calorifier. The TTZ is the one with no pump and relies on the engine pump, these are used both as preheaters but also as heaters due to engines so efficient you can't get enough hot air to heat the cab. These all link into the vehicle canbus and can't be used outside the vehicle they're pulled from. Some can, I think Rover and Jaguar, can't recall, but these ones go for more money. It all looks like a massive headache and best avoided.

 

[SquirrellCook]

Just checked and my D2 and lighting are pulling just 1amp or 29watts on a 24volt system this evening.

 

[mistericeman]

Most (if not all) eberspacher hydronic units have a circulation pump built it (I was going to fit one to the transit and have a fan/matrix wet system along with a multiplate heat exchanger for hot water....

Plenty of info on Lektons site as usual....

Water intro

Eberspacher Diesel Water Heater Introduction. Most of our air heater information also applies to water heaters

www.letonkinoisvarnish.co.uk

 

[Nabsim]

Most (if not all) eberspacher hydronic units have a circulation pump built it (I was going to fit one to the transit and have a fan/matrix wet system along with a multiplate heat exchanger for hot water....

Plenty of info on Lektons site as usual....

Water intro

Eberspacher Diesel Water Heater Introduction. Most of our air heater information also applies to water heaters

www.letonkinoisvarnish.co.uk

Will have to check the site again, I thought they didn’t have much on hydronic units last time I looked.