I think I found a heater booster, but no switch

Aqua Puttana

Poly - Thread Finder
Guys I need guidence too.
It appears I have no timer or wiring for a timer that may have been removed.
...
All this information is out in other threads. I am repeating. A search can be your friend.

The basic Espar heaters are a small self contained oil burner furnace as to firing. The heaters can be installed stand alone in boats and vehicles. The little furnace has a built in control module for the ignition, blower speed, flame monitoring, operating temperature control, and overtemp safety monitor.

To just fire up the Espar furnace needs a fuel supply (pulse pump), combustion air (internal fan), and an ignition source (glow pin).

The basic external requirements to fire up are:

Constant 12 volts to pin #1.
A proper negative ground connection pin #2.
A connection (wire) out to the dosing pump pin #4 (It is a conditioned pump signal. Not just 12 VDC.).
A 12 volt enable signal to pin #6.
A 12 volt enable signal to pin #7.

Pin #5 is for communication. It is not required.

The circulation pump is not required for the heater to fire up. The Espar control has no idea what the MB aux electric coolant pump is doing, or not doing until the heater go to over-temperature. Without proper coolant circulation the Espar heater will shut down on overtemp safety in a short time.

The Espar heater does run through an internal system check before firing. If there is a problem with the glow pin, flame sensor, blower, etc, then that will prevent the Espar heater from getting to startup.

Here is a basic diagram.

10.3.3 Booster.JPG

Added: As Vanski pointed out, the Espar coolant type heaters can even be test fired with no coolant. I wouldn't allow it to run for more than a very short time without coolant though. It will very quickly over heat and stress components.

vic
 
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tinman

Well-known member
I will be reading any replies you get!

I am in a similar position here in the UK. Have the bow tie switch, red led comes on, heater is there under the bonnet, but it doesn't come on. I am also looking to add the 7 day timer to mine.
Sounds like mine, which is to say very quiet. I pulled mine, took it apart and checked all the components. All OK, but I have no way of checking the control unit on the heater itself except functionally. Doesn't work, so I guess it's shot.
 

talkinghorse43

Active member

Aqua Puttana

Poly - Thread Finder
I was trying to edit some of my posts. Now my head hurts.

I'm confused.

Will the member who has the Espar heater with the solid, non-working Bowtie center medallion please raise their hand.

vic

Update: Found it. I didn't go back far enough in the earlier posts.

Ha! I promise you, it doesn't move one bit. It's as rock solid as anything. Any photos of the espar switch I've seen, there's a little wavy bacon logo to the left of it. I don't have a logo, but after very close inspection with a headlamp, I can see a spot for an LED. Also, those logos appear to be painted on to a black surface with a clear plastic surface over it, so I doubt it's been able to fade or rub off. There's no sign of any residual paint where the wavy bacon logo ought to be.

I've jiggled it, rattle it, thumped on it, blown on it. Doesn't move. =( How hard is the dash to get apart, I want to look at it from the back side.

Also, thank you for the beautiful drawing. =)
I misread this post.

I have the now famous "bacon bowtie" OEM booster heater [added: not the switch]. If I do the mod to run the booster with engine off I need an electric coolant pump. Does that exist in combination with the OEM booster, or does it rely on a engine run collant pump?
Bob
 
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glasseye

Well-known member
Awesome thread, boys. A couple of questions, if I may.

1) Any idea of the combined load in amps for the Espar, the coolant circulating pump and the blower fan? In other words, how long can I sit in the back of the van with the engine off, the heater on, reading a Tom Clancy novel before I run the battery down so low I can't start?

2) Any reason why I can't run this entire system from my aux battery so as to render question 1 moot?

3) The Espar needs two electrical signals according to Vic. 12VDC continuous to several locations on the Espar to power the unit AND a 12VDC "conditioned" signal. That is presumably the pulsed signal that's part of the temperature control feedback, right?. So, can I have a simple switch anywhere in the cargo area that does all of the above?

If the heater control switch is reachable without getting out of bed, I won't have to put my pants on at -15C like that one time in Wyoming. :idunno:
 

Aqua Puttana

Poly - Thread Finder
I have the now famous "bacon bowtie" OEM booster heater. If I do the mod to run the booster with engine off I need an electric coolant pump. Does that exist in combination with the OEM booster, or does it rely on a engine run coolant pump?
Bob
Was this answered?

I believe that the aux electric coolant pump is standard equipment on all NAS aka NAFTA 2004 - 2006 OM647 engine Sprinters. The aux electric coolant pump circulates coolant through the EGR.

For the NAS aka NAFTA 2001 - 2003 OM612 engines I'm quite certain that the only time an aux electric coolant pump is included is when there is an Espar heater ordered. (I may be wrong. :idunno:)

So basically, if you have any variation of the optional Espar heater you should have a pump.

vic
 
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Aqua Puttana

Poly - Thread Finder
Awesome thread, boys. A couple of questions, if I may.

1) Any idea of the combined load in amps for the Espar, the coolant circulating pump and the blower fan? In other words, how long can I sit in the back of the van with the engine off, the heater on, reading a Tom Clancy novel before I run the battery down so low I can't start?
The Espar native control module has a low voltage monitor and shut down. That *should* leave enough juice to start your engine. One factor against that is if the ambient is extremely low. In that case the battery output is compromised, and the engine may be very cold. Those two factors will work against you.

2) Any reason why I can't run this entire system from my aux battery so as to render question 1 moot?
There are threads which discussed that. To do it correctly takes more than just switching a couple of wires. Added: Mixing of aux battery and starting battery voltages to an Espar unit has some of the same potential pitfalls encountered when powering a head unit (radio) from two separate battery systems. You can fry some expensive electronic components if it isn't done correctly.

3) The Espar needs two electrical signals according to Vic. 12VDC continuous to several locations on the Espar to power the unit AND a 12VDC "conditioned" signal. That is presumably the pulsed signal that's part of the temperature control feedback pump operating signal, right?. [Yep... now.]
The 2 enabled signals are a regular old 12 VDC.

So, can I have a simple switch anywhere in the cargo area that does all of the above?

...
Once the controls are set up for constant run an enable switch could basically be mounted anywhere.

:cheers: vic
 
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ECU

Well-known member
I've done it. Not exactly sure that the fan is running from the aux battery.
But you could simply think of the aux battery as the jump battery when your standard battery goes down. In essence, leave everything on the start battery and the aux is your reserve.
Either way is actually quite easy. I have it done in a way that I can revert back to factory quite easily. Just replace fuses.
 

Arnie_Oli

Member
Well I think my Espar unit has seen better days. Appears that water has been dripping from the cabin air gasket that mates with the bonnet onto the heater and the battery tray. Result is one really rusty Espar, I will need to take it out and see if it can be salvaged.
 

autostaretx

Erratic Member
1) Any idea of the combined load in amps for the Espar, the coolant circulating pump and the blower fan? In other words, how long can I sit in the back of the van with the engine off, the heater on, reading a Tom Clancy novel before I run the battery down so low I can't start?
Many years ago when our Sprinter was young, i spent a slightly below freezing Xmas night in Maple Ridge BC. We got up every two hours or so (whenever we shivered awake or the bladders called) and punched the red button on the 7-day timer.
The front cabin fan was on 2.

Figure at least an honest 6 hours of operation from the year-old OEM starter battery, and no problem starting in the morning ... after breakfast (so the engine had an hour or so to cool down a bit)

If you were to ask me my guesstimate on the load, it would be 3 to 5 amps ... cabin fan speed being the swing vote. (yeah, i could go measure it, but i'll just guess given the manual's specifications).

--dick
 
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glasseye

Well-known member
Thanks, boys. Several hours worry-free operation would be adequate. I don't see myself running such a system overnight, I'd just like to avoid the morning getting-dressed-in-the-cold scenario. This sounds like my next big Frito project.

Oh, and by the way, Dick, Maple Ridge, BC hardly qualifies as "winter", ever. Even at Christmas. :tongue:
 

autostaretx

Erratic Member
Oh, and by the way, Dick, Maple Ridge, BC hardly qualifies as "winter", ever. Even at Christmas. :tongue:
Oh, yeah... Christmas is easy. It's Boxing Day (and the day after) when things get weird.

--dick :cheers:
 
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Aqua Puttana

Poly - Thread Finder

davisdave

2005 140 tall passenger
I think the dash fan takes up to 4.6 amps, and the water pump is less than an amp. Both of these items are powered by the wire you supply (existing plug behind shifter powers the fan, and the green/red wire you cut for the water pump). So, you can run these wires to the aux battery if you like:snore:
 

surlyoldbill

Active member
yeah, NONE of the lights come on on my HVAC controls, not even the +bacon indicator LED, although I hear the jet trying to take off by my front tire when it's "on". I need to get around to replacing those bulbs or something.
 

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