Fitting an Engine preheater

I've just bought this engine preheater.


and the instructions (I've translated from German) suggest these possible installation positions:

1. Integration into the heating circuit: The heater is mounted in the return of the internal radiator (standard assembly)
2. Integration via the expansion tank: If the expansion tank has several hose connections, integration into the return to the engine is possible.
3. Integration into the water circuit of the oil cooler: Installation takes place in the return.

I'm opting for number 2. as the instructions also state
'Installation must be carried out below the coolant expansion tank, it is necessary. That the heat exchanger is always filled with coolant. Attention ! The coolant pump is not self-priming.'

I'm assuming it will burn out if run dry.

I thought this pipe shown in the image below, what direction is the flow, all comments welcome.

direction is toward engine, the smaller hose to the front is the return to the tank, as god as place as any

jamesmartin said:

direction is toward engine, the smaller hose to the front is the return to the tank, as god as place as any

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So the hose on the left rather that the one on the right?
With the flow going towards and through the expansion tank...

How are you going to power it?

danny6801 said:

How are you going to power it?

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You start the engine and it connects to the alternator

danny6801 said:

How are you going to power it?

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It is mains powered and parked close enough to the garage to be plugged in.

I fancy making up a hinged water proof door and house the IEC socket where the blank dummy air intake is...

Being a bit thick, but what's it do?

Marmaduke said:

You start the engine and it connects to the alternator

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Its 230v if you look with your eyes lol.

danny6801 said:

Its 230v if you look with your eyes lol.

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OK smarty pants, you plug it in an inverter and run it off a fag lighter I thought you were an electrician

Cranium said:

So the hose on the left rather that the one on the right?
With the flow going towards and through the expansion tank...

Click to expand...

yes it wants to be in the hose on the right the one high lighted in red

Giantdog said:

Being a bit thick, but what's it do?

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It plugs into the mains and heats the water in the engine so you'll always have hot air coming from the vents as soon as you start your tratter as opposed to waiting for the engine to warm up so you can demist the windscreen on a cold morning.

Marmaduke said:

It plugs into the mains and heats the water in the engine so you'll always have hot air coming from the vents as soon as you start your tratter as opposed to waiting for the engine to warm up so you can demist the windscreen on a cold morning.

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That's a bit clever, I like that.
I had a diesel vectra and you had to wait 3 hours to get it warm enough to demist anything.
On a mildly chilly day I would often find myself feeling like Ernest Shackleton.

Marmaduke said:

OK smarty pants, you plug it in an inverter and run it off a fag lighter I thought you were an electrician

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Oh yeah 2.2kw off your cigarette lighter let me think hmmm I suggest fire maybe haha leave the leccy questions to the pros lol.

Giantdog said:

That's a bit clever, I like that.
I had a diesel vectra and you had to wait 3 hours to get it warm enough to demist anything.
On a mildly chilly day I would often find myself feeling like Ernest Shackleton.

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Assuming you've got a good quality and working thermostat and your heater matrix is clear your heater should start to get warm after a couple of miles

danny6801 said:

How are you going to power it?

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It was only a reply to this dumbass question

jamesmartin said:

yes it wants to be in the hose on the right the one high lighted in red

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I'm getting the suggestion on a Facebook group that it's better to put it in the heater pipes as this will flow round the engine better, only needs to be lowered slightly to be lower than the expansion tank.

that was my thoughts too, but for some reason my reply hasn't posted

Cranium said:

I'm getting the suggestion on a Facebook group that it's better to put it in the heater pipes as this will flow round the engine better, only needs to be lowered slightly to be lower than the expansion tank.

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pipe is a direct feed to the water pump and then block,iut is also going to be well fed even if coolant is low unlike heater pipes,you cant get a better position

it will have the added benefit of warm heater 1st thing too for clearing the screen

Marmaduke said:

Assuming you've got a good quality and working thermostat and your heater matrix is clear your heater should start to get warm after a couple of miles

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That's a good theory, but I can't drive until the windscreen is demisted and de-iced inside and out, I drive about a mile to walk the dogs in the morning at 6am.
So it would take 20 mins to get enough heat to be effective just running the engine after starting, the preheater will save me a lot of time.