What to expect from the auxiliary heater?

RedDino

Member
I am addressing this to all you folks who have a 2004-2006 Sprinter with the auxiliary heater option with the timer.

I don't know what performance to expect from the heater and I can't find anything that tells me.
I would appreciate if you could tell me how long it takes to reach a certain coolant temperature and noting the ambient temperature.
I am interested in the performance when the engine is cold (e.g. after a cold night outside) and the engine is off.

For example: Ambient temp 32°F
after 15 minutes: what is the coolant temp?
after how many minutes does the coolant reach 180°F? Does it ever reach 180°F or what is the max temp that you can get?

Please tell me you experience so I have something to tell the Mercedes tech who says that it will never reach 180°F and that I will never have it warm in the morning. On the other hand he wants to replace water valve. But if the aux heater doesn't really produce any heat, why spend another $800?

Thank you all much for your help!
Matthias
Sterling, VA
2004 140" low passenger
 

cahaak

New member
I can't say for sure as I never have the heater on long enough to get to 180, but at 32 outside, the coolant will be moderately warm after 15 minutes and quite hot after 30 minutes. You have a lot of mass to heat up there, so it does take some time to get how. In general, I use the aux heater to get the block warm for better winter starts and then if it is really cold - 0F and below, then I turn the heater on with the dash switch after I start driving until I get the coolant up to temp. The aux hater produces plenty of heat, the biggest issue that people have when trying to run it from the 7 day timer is that the electric coolant pump is shot, then the heater will frun for just a bit and kick out due to overheat of the coolant since it is not being circulated. If things are working fine, it should have that airplane sound from the exhast for the duration of the time that you have the heater on.

Chris
 

RedDino

Member
So, if you say quite hot after 30 minutes would that be maybe 150°F? Does warm air blow from the vents?
When I start mine it does sound like a jet engine, but after 45 minutes the temperature still shows below 110°F and the air from the vents is cold as ever.

Matthias
Sterling, VA
2004 140" low passenger
 

MillionMileSprinter

Millionmilesprinter.com
I'm in Philadlephia, so a little bit colder than you.
I love turning on the Espar half an hour or so before I head out in the morning. It warms the engine up very nicely and helps the van interior warm up quickly, too.
I don't think I ever reach 180 in the winter months, but it does get so warm in the van that my wife starts to feel car-sick. My engine temps do drop when I turn the Espar off, so I know it's doing it's job. I can't remember how much they drop by, but I would guess around 30 degrees or so.
If you aren't really noticing a difference with it on or off, it's probably not working.
Like Chris said, you will hear a "turbo/helicopter" noise coming from it when it's working right and you can stick your hand under the exhaust pipe by the front drivers-side wheel and feel the heat coming out.
 

MillionMileSprinter

Millionmilesprinter.com
Does warm air blow from the vents?
When I start mine it does sound like a jet engine, but after 45 minutes the temperature still shows below 110°F and the air from the vents is cold as ever.
YES- after 30 or fewer minutes you will feel warm air coming out of the dash vents WITH THE ENGINE OFF and even more warm air with the engine running.

That's weird that the air is cold. It should not be cold. Like I said in my other post, it gets so hot in the van that we have to take off our coats and my wife feels sick.
I'm not familiar enough with the Espar operation that I can explain why it runs but doesn't warm up the cabin air or the engine.
If it were just the cabin air that was cold, I would suggest checking your heater vents and flap operation, but you said that the engine temps also don't go up. I can't explain that.
Maybe someone else will chime in. :idunno:
 

flman

Roadrunner, Genius of Birds ALWAYS WINS! NO FAILS!
So, if you say quite hot after 30 minutes would that be maybe 150°F? Does warm air blow from the vents?
When I start mine it does sound like a jet engine, but after 45 minutes the temperature still shows below 110°F and the air from the vents is cold as ever.

Matthias
Sterling, VA
2004 140" low passenger
Change the thermostat would be the first thing in order in that situation. The rad will cool the Espar just as effectively as it cools the engine.
 

Amboman

New member
When I start mine it does sound like a jet engine, but after 45 minutes the temperature still shows below 110°F and the air from the vents is cold as ever.
You have a failed water heater recirculation pump, they have well known issues as the manufacturer has decided to use brushes which are too soft and wear out, the pump is easily visible and mounted on the engine firewall check first if 12 volts is going there its 2 wires only and an easy test, the heater will warm the entire van in 10 minutes and blow hot air as well as warming the engine block it cuts off at around 80 degrees c for safety reasons, the rotating dial heater thermostat on your dashboard has a direct link to the temperature so if you have heater selected to blue cold that's what you will get.
 
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autostaretx

Erratic Member
For example: Ambient temp 32°F
after 15 minutes: what is the coolant temp?
after how many minutes does the coolant reach 180°F? Does it ever reach 180°F or what is the max temp that you can get?
Exactly how i used to run it (before i retired)... i'd dash out and punch the red button 15 minutes before leaving for work.
I'd do this any day the air temp was below 40F, so my "tests" were usually in the 28F to 35F range.
By the time i went outdoors, the frost/ice on the window would be softened enough for easy "push" off instead of hard scraping.
Water temp was probably 110F or so (i didn't bother to scangauge it... should'a).
Five minutes of in-city driving later (at a traffic light) i'd see that the temp was exceeding 150F, and the cabin air blast was fairly warm.
That's when i would turn OFF the Aux Heater.
If outside air temp was below 32F, the water temperature would start to drop a bit for the next 5 minutes of mostly-level 30 mph driving.

The *real* test i gave the heater was one overnight camping in sub-freezing Coquitlam BC (20 to 25F?).
We'd get up every two hours or so and punch the button to restart it.
It kept the entire cargo area (except the lowest "foot above the floor" zone) about 45 to 50F or higher (warmer near roof, heat rises).
Since we have a passenger wagon, the sides are all glass... lots of heat-loss. They stayed fog-free.
We've also removed the pretty dress wall panels, so we have less "insulation" than a normal wagon.

As a comparison, we've kind'a duplicated that situation, but with a 600 watt 120vac oil-filled electric radiant heater running all night in the van.
(thermostat knob 2 feet off floor set to "3" out of 9, but i don't recall if it ever cycled or just ran "on" all night)
The "test" nights haven't been quite as cold (30 to 32 F) as that clear night in Coquitlam, so the electric heater hasn't had to work as hard. We have a curtain separating the cargo/bed from the front cabin.
Results were similar.... definite thermocline about 1 foot off the floor (wheel well height?), then "warm enough" from there on up.
50F on a thermometer mounted on the rear door pillar about 2 feet off the floor.

The Espar is 5000 watts at "full toot", and 2500 watts at idle. Our in-cabin electric heater isn't dealing with the engine or the inefficiency of trying to have the front air ducts heat the rear cargo area (thus lots of losses through the sky-facing windshield and front windows)

The Espar definitely helps on 25F days, it can reach 180F water temperature during in-city driving (those days i left it on for 15 minutes of driving after the 15 minute warm-ups... and i think it did it even if i didn't do the pre-warmups.

--dick
 
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cahaak

New member
Make sure that your temp control knob on the dash is set to full red (heat). When you run the Espar from the switch, you should ge warm air from the vents. Espar will not run if the electric coolant pump is not working, but it may not be working as well as it should. No coolant should be flowing through the radiator at this time, so if for some reason your thermostat was stuck open, then the radiator would cool down the coolant drastically (it should not under these conditions). The other thing to check is to make sure that your cabin air filter is clean and that you are getting proper air flow through the heater coils. Based on what you are describing for operation, it sounds like your thermostat may be stuck open. Initial Espar operation should only circulate the warm coolant through the block and heater coil, not the radiator.

Chris
 

sprintguy

16+ yrs Master Commercial technician
O.K. old system... the aux heater with timer works with the vehicle off.. when the vehicle is running there should be another switch on the a/c heater control head in the middle of the a/c on and rest function switch. press that to keep the heater in booster mode. As for the coolant temp never rising over 110 degrees F , change the thermostat. To check the aux electric coolant pump start the van locate the pump (straight back from the egr valve, as a matter of fact the coolant feed to the EGR valve comes from the pump follow the hose back. on start up the pump should be on.

Good luck: Carl
 

autostaretx

Erratic Member
the aux heater with timer works with the vehicle off..
It also fires up the heater with the engine running... (at least in my 2005 Passenger Wagon)
I never use the A/C "bar" to control it.. only the 7 day timer. (far easier to reach from the driver's seat)

--dick
 
I've recently had some experience on this subject. My Auxiliary heater would perform the same as the original poster. That is, the fan would blow cold air while the Espar would attempt to fire. The Espar would eventually fire, but not for long because (I later found out) the water pump was not running. Jim Rixen at Rixen Enterprises in Sandy, OR, diagnosed my problem, and then installed a new water pump. All seemed fine, and so my wife and I and our infant son went camping on the coast Friday night. It turned out to be a cold night. The Espar would not fire. When I checked under the hood in the morning, I saw that the plug to the water pump had jostled off on the drive to the coast. I plugged it back in, but the pump wouldn't run anymore. I went back to Jim Rixen yesterday. He was surprised to see that the brand new pump had failed. At no charge, he upgraded the pump to a new Bosch brushless pump. Everything seems to be working now. If anyone is interested in the exact model of pump, please let me know. I'll try to remember to report back after a reasonable period of successful operation.

Off topic: Unfortunately, on the way home from Jim Rixen's shop, I started hearing a strange noise at idle. It looks like my pulley tensioner will need to be replaced. I'm awaiting word from Upscale Automotive now. My wife is starting to view our new van as an expensive undertaking.
 

RedDino

Member
Thank you for all your posts and help!
The culprit was indeed the circulation pump. Had it replaced by the Mercedes dealership in Chantilly, VA and now it's finally blowing warm air!
The techs at the dealership seemed fairly experienced and I'm happy to have found someone who can provide service. Just a little on the expen$$ive side...
Hope to see all you East Coast Folks at the Sprinterfest in April in PA.
 

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