this Bl**dy Heat exchanger....

[haganap]

I have a problem with my heat exchanger.
Basically, it doesn't work. simple really.... I have a list of symptoms and things I've tried. Then the bigger problem...
Firstly, for those who would rightly ask and look for "user error" as it's easy done. I have gone through every scenario, every combination to get it working...
so just to recap (many vans are different)

Valve is turned correcty (tried both ways anyhow)

on mine, I have a fan switch which is pressed to start the heat exchanger. The tempreture needs to be set high, and it is, I have tried th pump on thermostat I've tried in on constant.

i have a blue radiator on the panel and this is for sending heat to the engine. I have used this, and then when I start the engine, almost immediatly the fiat air vents are nice and warm, so it appears it's working that way..

At the heat exchanger it'self, there is heat to it when on gas/electric and there is heat the other side of it aka, it's heating the engine.
If I run the engine, there is no heat in the pipes at the heat exchanger. (without gas obviously)

I have checked a number of fuses and I understand there is a solonoid there too.


Today, I had a towbar fitted and they were meant to look at it. When I got there, the guy said "whats a heat exchanger" therefore they fitted the towbar and nothing else.
I came home and spoke with Alde themselves who were very helpful.. They said "it all looks ok in the hab side"

I've since spoken to fiat who again said "whats a heat exchnager" so I am now left with going to my local trusty mechanic for him to have a look.

However, I have no idea what I can ask him to look at? what are we looking for? what's the best way to approach it? is it likely to be electrical?. how does it actually work? If i could explain that to him we might have a chance of knowing what we are looking for. Granted i can see some pipes that come through the bulkhead but without dismanltling loads of things, I don't know what we are looking for?

Any ideas great received, any budding mechanics that can fix it, shout up.

I am now lost.

 

[mitzimad]

im at bit confused as to what this heat exchnger is supposed top do paul you obviously have alde heating which is working in the hab area and you seem to be able to preheat the engine so the only thing i can think is the aldi system isnt working from the engine to heat the hab area? is that correct?

 

[haganap]

im at bit confused as to what this heat exchnger is supposed top do paul you obviously have alde heating which is working in the hab area and you seem to be able to preheat the engine so the only thing i can think is the aldi system isnt working from the engine to heat the hab area? is that correct?

yes, the heat exchanger uses the heat from the engine when travelling to heat the alde rads and give hot water, essentially saving gas.

I think, hot water from the engine coolant system should come to the exchanger whereby a seperate pump then pumps it round the system. At present, I am not getting any heat to the exchanger.

 

[Ridgeway]

No AMV on yours Paul ?

 

[lorger]

When you say it works one way but not the other, has someone fitted a non return valve or similar without you knowing about it.

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[haganap]

No AMV on yours Paul ?

? what's an AMV

 

[haganap]

When you say it works one way but not the other, has someone fitted a non return valve or similar without you knowing about it.

no, they come fitted with some additional heat pump as an extra.

 

[lorger]

Think they’re similar to a non return valve as in one way.

Meant to quote your question about amv

 

[Steve and Denise]

Paul
The 2way heat exchanger is basically tapped in to the heater pipes from the engine side so when your engine is running at temperature the engine water circulates through the heat exchanger, some have a shut off valve on the engine side I have had both types,
You have established that the pump works to pre heat your engine, this has no effect the other way around.
For your hab heating to make use of engine heating make sure your exchanger is getting hot from the engine, once you establish this simply put on your hab heating at a set temperature (higher than ambient) and turn of the gas, make sure your Alde circulator pump is set to thermal, Bobs your uncle we have had 4 vans with this system all worked a treat. If your struggling to get to grips with it give me a shout.

 

[Steve and Denise]

no, they come fitted with some additional heat pump as an extra.

No extra pump for circulation only the Alde circulation pump fitted

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[lorger]

No extra pump for circulation only the Alde circulation pump fitted

Although I don’t have the system that’s my understanding of it, as for a heat exchanger it’s pretty simple system as long as the water flow from engine is getting to it.

 

[funflair]

Paul, the heat exchanger consists of several alternating plates with engine coolant going through let’s call them A and then adjacent ones let’s call them B have Alde fluid running through them, the Alde side is all inline with your Alde radiators hence needing the Alde pump running, the engine water to heat it should circulate by the engine water pump, when the engine is not running but you want to warm it there will be a little electric pump that switches from the control panel most likely and on our Flair so think not was called “motor” this circulates the engine water through the plate heat exchanger taking heat from Alde to the engine.

If the engine gets warm this would suggest everything is plumbed correctly, whatever the issue it it must be on the engine code, in the Flair and in the MORELO we had/have nothing more than a valve to open the engine circulation (closing this stops any inadvertent heating in the summer) your N+B might have something a bit more complex but as I say it has to be on the engine side as the Alde side is just one pipe going all the way around.

 

[funflair]

No extra pump for circulation only the Alde circulation pump fitted

If you can preheat the engine there should be a small electric pump Steve, our Flair had it but the MORELO doesn’t have that option only the ability to take engine heat to the Alde which as you say only needs the Alde pump running.

 

[G7UXG]

When the engine is off and the Alde heating is on in the van, there is a pump which circulates the engine’s coolant to pre-warm the engine. Obviously the Alde pump is also on to circulate the water through the Alde pipes and radiators. They are two separate water systems, linked by the heat exchanger. The water from the two systems doesn’t mix.

When the engine is running, the separate electric pump (not the main Alde heating circulation pump) should be switched off, otherwise you have the engine’s water pump fighting against the separately switched engine pre-heat pump. Mine is a Carthago but I’m sure it’s the same. It warns you that having the separate pump on whilst the engine is running may damage the system.

Are you leaving the separate pump switched on as well as the Alde pump? If so, that may be the problem.

With the engine running, the only pump that should be on is the one that is close to the Alde boiler, I.e. the main pump.

Edit: I think funflair wrote something similar.

 

[JockandRita]

I think, hot water from the engine coolant system should come to the exchanger whereby a seperate pump then pumps it round the system. At present, I am not getting any heat to the exchanger.

As you will know Paul, our system is older and less techy than yours, ie, no panel, just switches, however the principle must surely be the same or similar.
1. Isolation valve at the heat exchanger open, (inline with the pipework).
2. Alde heating pump only turned on, and thermostat set to your preference.
3. Drive. ..................

As Steve says, the engine pre-heater pump plays no part in the engine to hab area heating.

Good luck sorting it out.

Cheers,

Jock.

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[Steve and Denise]

Although I don’t have the system that’s my understanding of it, as for a heat exchanger it’s pretty simple system as long as the water flow from engine is getting to it.

Correct

 

[Steve and Denise]

If you can preheat the engine there should be a small electric pump Steve, our Flair had it but the MORELO doesn’t have that option only the ability to take engine heat to the Alde which as you say only needs the Alde pump running.

Only needs a separate pump for preheat of engine as I said but not easy to be totally clear in a few lines Martin

 

[funflair]

Paul, here is a bit of lateral thinking, does it actually have the heat exchanger from the engine or is it just a system to provide instant heat to the windscreen and cab via the Alde heat, have you found the heat exchanger and does it have 4 pipes to it? If yes you need to make 100% sur that it actually warms the engine block to prove the plumbing.

 

[CazPaul]

We have Alde but no heat exchanger, you can get them retro fitted but I’ve never seen the point. At first I thought I’ll get one but when we started using the system I realised we didn’t need it, we had a similar system in a previous van(Eberspacher engine/water heat while you travel)

Our Alde heats up in 15 minutes on gas plus we have a separate Truma E2400 gas heater.

It may cost you plenty to repair to save you pennies, I’m all for gadgets if there’s a need for them.

 

[G7UXG]

We have Alde but no heat exchanger, you can get them retro fitted but I’ve never seen the point.

They work great. On a decent journey, the habitation area gets toasty. Free heat that would otherwise be wasted.

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[haganap]

Ok, sorry to add more woes...

I probably not made it as clear as I should have.

Lets forget the engine pre heater as that works as it should.

In order for my system to work- The engine runs, there is then a fan button on the dash, this is to then activate the heat exchanger. It clearly opens (and closes) something on the engine side or pumps the fluid through to the heat exchanger.

Step back a bit.

With the engine running and nice and hot, there are two pipes that come in to the van at the bulkhead that run down to the heat exchanger. These are stone cold, therefore they are not sending any heat to the exchanger where it can be "exchanged" to make the alde system heat the van.

Just to say also, I have had this on two previous vans, I am familiar with how they should work and in any case I have tried every combination to make it work... the fan switch operates my system even being told this by N&B the other week when I was there.

What is stopping them pipes from the engine, that go through the bulkhead, getting hot? where and what does my fan button operate.

Thanks

 

[haganap]

Paul, here is a bit of lateral thinking, does it actually have the heat exchanger from the engine or is it just a system to provide instant heat to the windscreen and cab via the Alde heat, have you found the heat exchanger and does it have 4 pipes to it? If yes you need to make 100% sur that it actually warms the engine block to prove the plumbing.

Yes, the heat exhanger is sat behind my drivers seat, it has all the pipework in to it from the engine, not counted the pipes but I can see them coming under the floor and off to th bulk head.

 

[haganap]

We have Alde but no heat exchanger, you can get them retro fitted but I’ve never seen the point. At first I though I’ll get one but when we started using the system I realised we didn’t need it, we had a similar system in a previous van(Eberspacher engine/water heat while you travel)

Our Alde heats up in 15 minutes on gas plus we have a separate Truma E2400 gas heater.

It may cost you plenty to repair to save you pennies, I’m all for gadgets if there’s a need for them.

one of those things that when you have had it, you woudn't want to be without it.

 

[Steve and Denise]

Ok, sorry to add more woes...

I probably not made it as clear as I should have.

Lets forget the engine pre heater as that works as it should.

In order for my system to work- The engine runs, there is then a fan button on the dash, this is to then activate the heat exchanger. It clearly opens (and closes) something on the engine side or pumps the fluid through to the heat exchanger.

Step back a bit.

With the engine running and nice and hot, there are two pipes that come in to the van at the bulkhead that run down to the heat exchanger. These are stone cold, therefore they are not sending any heat to the exchanger where it can be "exchanged" to make the alde system heat the van.

Just to say also, I have had this on two previous vans, I am familiar with how they should work and in any case I have tried every combination to make it work... the fan switch operates my system even being told this by N&B the other week when I was there.

What is stopping them pipes from the engine, that go through the bulkhead, getting hot? where and what does my fan button operate.

Thanks

If it’s got a fan symbol on it it’s probably the heater fan under the passenger seat.

 

[Landy Andy]

Have you checked for an air lock at the valve or heat exchanger. Whatever is higher?

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[haganap]

If it’s got a fan symbol on it it’s probably the heater fan under the passenger seat.

no I think this is to actually run an alde pump, thats what Alde say as well. They say its definately to do with th alde system to make it work....
On one of my vans it wasnt needed, you just turned the valve on the exchange to be off or on.

 

[haganap]

Have you checked for an air lock at the valve or heat exchanger. Whatever is higher?

I've bled it at the heat exchnager if thats what you mean Andy? But is there a way it could have an airlock from the engine side?

 

[Steve and Denise]

I've bled it at the heat exchnager if thats what you mean Andy? But is there a way it could have an airlock from the engine side?

If that was the case it would not pre heat the engine

 

[bigtwin]

We have a valve in the engine bay that will isolate the HX. Are you sure that the HX is valved in?

Ian

 

[haganap]

We have a valve in the engine bay that will isolate the HX. Are you sure that the HX is valved in?

Ian

ok, that's what I am looking for....

I know there is a valve on the heat exchange itself which I have checked,

anyway you could describe what you mean? or what the valve looks like? I'm thinking something on the engine side that is shutting off the flow to the exchanger.

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