[seapro]

Observing threads on this forum it appears that there are numerous questions concerning installation of Espar heaters, especially the commonly used D2 air heater.

Espar publishes an extremely detailed product catalog that includes information on hundreds of parts and discussions of topics of interest. A link to the December 2014 version (the latest?) is:

http://www.eberspaecher-na.com/file...s/EB_Kanada/pdf/Product_Catalogue_05-2014.pdf

I call attention to the following:

Page 39 -- a small diesel tank for use in gassers.

Page 42 -- part number 5540016 a bracket that allows mounting a D2 on a vertical surface.

Page 55 -- exhaust parts.

Page 58 -- ducting parts.

Page 70 -- a very important fuel system guide and rules.

Page 71 -- important info on ducting rules so that excessive back pressure is not caused which causes heater to overheat.

Page 73 -- specific ducting parts for the D2

Over time I have answered many questions about installation due to almost 50 years of using these heaters in boats and vehicles.

In the next post I will offer some thoughts.

 

[seapro]

In the front of the Product Catalog various "kits" are shown that include a slew of parts needed for a typical installation. To simplify things and save cost it is best to start with a "truck kit" for the D2. Additional parts are then ordered separately.

In order get the best even heat the hot air should be ducted to the opposite end of the van than the location of the cold air return. For the D2 in a Promaster it is best to increase the duct size up one size from the small size usually supplied. Using the ducting rules be sure to keep well within the guide lines so back pressure is kept low otherwise the heater can overheat causing serious problems. To accommodate larger duct size at the hot end order the "hood" to go on the hot end of the heater and the "ring" for the cold air inlet. Various ducting parts are available. For the Promaster generally only one outlet is needed and the elimination of "T"s and "Y"s reduces back pressure.

Be sure to observe the fuel system rules. It is vital that things go uphill to move bubbles along. Be sure that tubing physically meets within the coupling hoses otherwise a bubble can be trapped and block fuel flow.

Combustion air should be taken from below the van floor properly shielded to prevent road dirt and water from entering. Generally this means aiming the air inlet hose aft. Exhaust should also be down through the floor into the muffler as it makes a huge reduction of noise. Output from the muffler should use additional exhaust hose aimed aft under the rear bumper or out the side from underneath. Don't get obsessed about t keeping the air intake away from the exhaust.
If the exhaust is aimed out from underneath a foot or so separation should be OK.

A next post will discuss controls and wiring.

 

[seapro]

Final of 3.

It is vital that full voltage and current be available. The heater draws up to 50 amps in short pulses for the first few seconds to heat the pin type glow plug and initiate combustion. A major cause of problems can be difficulty starting combustion causing sooting up of the combustion chamber and maintenance problems. A quick, hot, pin plug saves problems. Connect fused wiring harness directly to the house battery. Do not ever start heater when the house battery voltage is down such as when an inverter is running a microwave oven!

Do not shorten wiring harnesses provided.

Over the decades Espar has had many controllers as technology has evolved. The best and simplest is, in my mind, the current Digi-Max Controller as it works well with the tiny computer within the cold end of the D2 burner. It is simple to use. I recommend staying away from timers for a class B camping van.

There is one vital wiring option left up to the installer's choice for all controllers and this has to do with temperature sensing (thermostat) location. Remember that your home furnace starts and stops as the thermostat is satisfied. Not so with the D2 which generally remains running regulating heat by modulating fuel flow and fan speed. This means that cabin air is continuously being returned to the heater. There are two choices -- monitor the temperature at the controller or monitor the temperature of the return cold air as it enters the burner. Based on my experience the best results and most even heat is to default to temperature sensing in the cold air return at the heater. The choice is made by connecting or not connecting a gray colored wire at one connector. BE SURE TO FOLLOW DIRECTIONS CAREFULLY ABOUT THIS.

For initial start-up combustion chamber sooting can be reduced by using a turkey baster to suck fuel up to the final connection at the heater. Turn the heater on at the controller and wait. Normal start-up sequence takes time as the fan runs to clear out the combustion chamber and draw in fresh air. If it does not fire the first attempt continue to wait as it will rest than start the sequence again. It should fire by the third attempt; if not it will shut down and you will need to start again. When it goes off let it run initially for several minutes.

 

[RDinNHandAZ]

Thanks seapro,

I bought a D2 airtronic air heater and a digimax controller, installed it consistent with their (and your) directions and have it set to monitor the return air. Anyone thinking of doing this can easily accomplish a correct installation on their first try. I have pictures on my build thread. I am very happy with it as a heater for my Van.

I used garyBIS’s insulation calculator (see below) to allow enough heat loss at 30 degrees fahrenheit to keep the airtronic from needing to shut off and restart during the night. This heater is a bit noisy on startup but settles to a nice low ambient fan noise and a slight tick for the pump. If you over-insulate the van the heater will shut down, restart, shut down, restart........

Find the calculator at: http://www.builditsolar.com/References/Calculators/VanHeatLoss/VanHeatLoss.htm

 

[seapro]

Good comments about insulation and figuring heat loss. I have two Maxxair vent fans and in cold weather I leave them open without the fans running to get some fresh air. Most folks just "wing it" re amount of insulation.

I should remind folks that the heater will shut down automatically after 10 hours even if heat is called for. When using the heater all evening I shut down and restart before bedtime so that it does not shut down during the night.

 

[buck]

Why did you go with a D2 (diesel) and not a B2 (gasoline)?

 

[seapro]

I remember gasoline heaters in early VW Beetles and Chevrolet Corvair cars that had air cooled engines. They had problems including major safety issues. Both companies eliminated the gas heaters and switched to air ducted over the hot cooling fins of the cylinders. Much safer but if there was the tiniest oil leak the odor got into the car.

If a gasoline heater has a problem with a leak the vapor can be explosive. A diesel leak will cause an odor but no explosion.

It is easy to add a small diesel tank to a gasser. Two to five gallons should be sufficient as for a typical cold night only a couple of cups of fuel will be used! It is amazing how much heat energy is in diesel fuel and how little is used by an Espar D2.

 

[farmike]

Thanks seapro,

I bought a D2 airtronic air heater and a digimax controller, installed it consistent with their (and your) directions and have it set to monitor the return air. Anyone thinking of doing this can easily accomplish a correct installation on their first try. I have pictures on my build thread. I am very happy with it as a heater for my Van.

I used garyBIS’s insulation calculator (see below) to allow enough heat loss at 30 degrees fahrenheit to keep the airtronic from needing to shut off and restart during the night. This heater is a bit noisy on startup but settles to a nice low ambient fan noise and a slight tick for the pump. If you over-insulate the van the heater will shut down, restart, shut down, restart........

Find the calculator at: http://www.builditsolar.com/References/Calculators/VanHeatLoss/VanHeatLoss.htm

Thats good info to think on as I continue to ***** the upper channels with polyiso foam pieces...
looking at your build photos I had wondered about the effectiveness of the insulation in the rear corners with so much open space behind the insulation.

 

[RDinNHandAZ]

It is important for me as I sleep along the back. I pulled the door panels and insulated there too. In those corners Hein’s Thinsulate would be a good option although I did not use it. What you want to avoid is a cold source near your head or feet on a cold night! Keep at it, it works. I did not do the front doors nor overhead in the front storage over the cab.

 

[buck]

I'm building a four-season van and will regularly be in temperatures below 0°*F (-20° F with windchill). The B2 and B4 are quite a bit more expensive than the diesel version, presumably because they're not as common. The appeal of having a single fuel source (gasoline) is that I wouldn't have to worry so much about running out of diesel fuel (unless I got a big diesel tank, not sure what capacity fits) and having one fuel source is just simpler. I'll probably be using LP for the stove (diesel and gasoline take a while to heat/cool and I don't think induction is ready, especially in the winter when there isn't much sun); having three fuel sources would be way too much for me to keep track of...unless someone convinces me otherwise.

I don't see any down side to 'over' insulating, other than cost, losing a tiny bit of volume, and adding some weight. You can always open a vent to adjust the temperature to prevent the heater from restarting in the night. I'm debating the B4. It doesn't use much more fuel or electricity than the B2 or D2, and last winter I was freezing the entire time in my '97 VW Rialta. Granted the insulation in that rig is 20 years old and there are tons of windows...but still, being cold sucks. I suppose I ought to look at the calculator and determine which heater would work the most efficiently, which I've gathered also means longer service intervals.

 

[RDinNHandAZ]

You are right. If you have propane there are lots of RV propane furnaces by Suburban, Propex, Atwood and others. Why not use one of those and be back to 2 fuels? No furnace is going to use less fuel to heat your van than the Diesel. Seapro gave you good advice and has long experience with them.

 

[Nexus6]

Agree with RD. If you're already doing propane then there's little reason to hassle with an Espar. A Propex heater can be had for much less and is reliable, quiet and easy to install.

Sent from my Nexus 5X using Tapatalk

 

[farmike]

In the front of the Product Catalog various "kits" are shown that include a slew of parts needed for a typical installation. To simplify things and save cost it is best to start with a "truck kit" for the D2. Additional parts are then ordered separately.


Be sure to observe the fuel system rules. It is vital that things go uphill to move bubbles along. Be sure that tubing physically meets within the coupling hoses otherwise a bubble can be trapped and block fuel flow.

.

Hi Seapro
I noticed on another commentary the rule about the incline for the fuel pump for the D2 airtronic heater. It brings to mind your mention that the heater itself was installed so many inches above the floor in your van. Im wondering about a floor level install and attaching a fuel tank to the wall above. Would this be an issue or is it just a matter to make sure the fuel line drops down below the heater level?

 

[seapro]

farmike --

This raises several questions but it is possibly doable. I assume you have a gasser if you are planning a separate fuel tank. (If you have a diesel you would draw fuel from the van's tank and install the fuel pump underneath the van.)

If the burner is literally on the floor and the diesel tank above I do not see how the fuel would connect to the burner. Would the fuel line go down from the tank through the floor as that would be necessary to connect to the bottom of the burner assembly? I would suggest that the fuel tank be below the floor or better yet have both inside with the burner raised above the floor several inches to allow access for fuel, combustion air, and exhaust connections inside the van. The combustion air and exhaust would lead down through the floor. The fuel tank and line would all be inside. The burner can be mounted on a shelf or better yet use the available bracket for mounting on a vertical surface.

Now to your question itself. Remember that the fuel pump is a pulsed device good at pushing fuel towards the burner but poor on sucking fuel from a tank. There are two different types of tanks: One where the fuel drains from the bottom and one where the fuel is sucked out the top of the tank. In either case I would place the pump no higher than two feet above the lowest fuel level in the tank. It is fine if the pump is below.

I would get all the fuel system parts installed but not connected except at the tank. Then use a turkey baster or otherwise suck fuel to the pump then connect that input to the pump. Then suck fuel fuel through the pump. Then connect the output of the pump and capillary tubing towards the burner, suck fuel again, then make the final connection. All air should be out and everything will be fine.

The important thing is that the area of the pump and its connections should be up hill. I have done one successful installation where the pump was vertical on top of a tank. After the connection to the capillary tube, that tube can go up and down hill, over valleys and mountains so long as it goes up hill into the bottom of the heater. This heater connection can be lower than the high point above the fuel pump. If there are no connections in that capillary run there are no places for air to enter or bubbles to get trapped. Tiny bubbles will move through the tube.

Now that I have written all this BS another though has come to mind. I have been assuming the pump would be near the tank. The fuel pump makes a clicking sound which some folks consider an annoyance. Best might be to have the pump underneath the floor and all heater connections underneath.

This may be more confusion than help. I will try to be clearer if you pose additional detailed questions.

 

[RDinNHandAZ]

I have very little experience as I have only done my install. Here are my observations. The pump does make a pulsing noise I would not like to have inside the van, we can hear ours that is mounted in a very good rubber mount outside the van. We still hear it but it is diminished enough to ignore. The pump must have fuel provided to it by gravity as seapro says. Ours comes from the van’s tank and is siphoned up out of the tank then down the tube to the pump that is below the floor. The siphon was started and has not failed for well over a year and if I were to disconnect the tube at the pump fuel would flow. The pump must angle upward and be connected to a small tube (capillary says seapro) via a fitting and this is where there can be no air trapped and none will be if the fitting is tight which is easy to accomplish. I made sure the capillary tube rose all the way back up to my heater which could have been up under the seat or elsewhere. For the sound of the pump and the need to have the capillary rise the pump needs to be below the floor.
I hope this helps clarify seapro’s excellent description.

 

[farmike]

farmike --

This raises several questions but it is possibly doable. I assume you have a gasser if you are planning a separate fuel tank. (If you have a diesel you would draw fuel from the van's tank and install the fuel pump underneath the van.)

If the burner is literally on the floor and the diesel tank above I do not see how the fuel would connect to the burner. Would the fuel line go down from the tank through the floor as that would be necessary to connect to the bottom of the burner assembly? I would suggest that the fuel tank be below the floor or better yet have both inside with the burner raised above the floor several inches to allow access for fuel, combustion air, and exhaust connections inside the van. The combustion air and exhaust would lead down through the floor. The fuel tank and line would all be inside. The burner can be mounted on a shelf or better yet use the available bracket for mounting on a vertical surface.

Now to your question itself. Remember that the fuel pump is a pulsed device good at pushing fuel towards the burner but poor on sucking fuel from a tank. There are two different types of tanks: One where the fuel drains from the bottom and one where the fuel is sucked out the top of the tank. In either case I would place the pump no higher than two feet above the lowest fuel level in the tank. It is fine if the pump is below.

I would get all the fuel system parts installed but not connected except at the tank. Then use a turkey baster or otherwise suck fuel to the pump then connect that input to the pump. Then suck fuel fuel through the pump. Then connect the output of the pump and capillary tubing towards the burner, suck fuel again, then make the final connection. All air should be out and everything will be fine.

The important thing is that the area of the pump and its connections should be up hill. I have done one successful installation where the pump was vertical on top of a tank. After the connection to the capillary tube, that tube can go up and down hill, over valleys and mountains so long as it goes up hill into the bottom of the heater. This heater connection can be lower than the high point above the fuel pump. If there are no connections in that capillary run there are no places for air to enter or bubbles to get trapped. Tiny bubbles will move through the tube.

Now that I have written all this BS another though has come to mind. I have been assuming the pump would be near the tank. The fuel pump makes a clicking sound which some folks consider an annoyance. Best might be to have the pump underneath the floor and all heater connections underneath.

This may be more confusion than help. I will try to be clearer if you pose additional detailed questions.

Thanks seapro, thats lots of good info.
I have a gasser and plan to put the heater and diesel fuel tank inside; I see now I will have to raise the heater enough for the fuel line to go up to the heater.
I'm envisioning the install and thinking of putting the heater just in front of the rear passenger wheel well in a box with a little sound dampening, I have some thinsulate and foam board available. Also, the 3gallon tank fastened to the wall with the fuel line out the top next to it. I haven't settled on the floor plan yet so the install may be elsewhere but the wheel well area is unobstructed underneath.
What I didnt have clear was the need for the fuel line to enter from below the heater and the pump to be below.

 

[farmike]

I have very little experience as I have only done my install. Here are my observations. The pump does make a pulsing noise I would not like to have inside the van, we can hear ours that is mounted in a very good rubber mount outside the van. We still hear it but it is diminished enough to ignore. The pump must have fuel provided to it by gravity as seapro says. Ours comes from the van’s tank and is siphoned up out of the tank then down the tube to the pump that is below the floor. The siphon was started and has not failed for well over a year and if I were to disconnect the tube at the pump fuel would flow. The pump must angle upward and be connected to a small tube (capillary says seapro) via a fitting and this is where there can be no air trapped and none will be if the fitting is tight which is easy to accomplish. I made sure the capillary tube rose all the way back up to my heater which could have been up under the seat or elsewhere. For the sound of the pump and the need to have the capillary rise the pump needs to be below the floor.
I hope this helps clarify seapro’s excellent description.

Thanks RD, I was getting stuck on capillary; like in veins

 

[tgregg]

I have a gasser and plan to put the heater and diesel fuel tank inside; I see now I will have to raise the heater enough for the fuel line to go up to the heater.

I have a gas Promaster also and I have a 3 gallon diesel tank mounted inside about 4 inches above the floor. I am mounting the D2 directly on the floor. The fuel line comes out of the top of the tank and will go down through the floor to the fuel pump mounted under the floor at an upward angle and then connect to the bottom of the D2.

I had a D5 in my previous camper and a diesel cooktop in this one and the previous one and I definitely want the noisy fuel pump mounted below the floor.

 

[seapro]

I concede that the pump is noisy and best below the floor for most installations and I have had that on two previous vans. My current setup has the pump above the floor with noise reduced by using the rubber pump ring supplied, and the entire system -- tank, pump, and burner -- above the floor but isolated in a separate insulated double wall wood enclosure. The combustion air and exhaust go through the floor. The hot air and return air ducts go into the van. My installation is at the rear with the return air duct there, but the hot air is ducted at floor level to the front of the van so there is even heat throughout. This works great with temperature sensing defaulted to the cold air return at the burner not the controller (see my posts at the beginning of this thread). Noise is also reduced by going up one size of duct work (see same).

I am in southeastern Virginia if anyone wants to come see.

 

[farmike]

The fuel pump under the vehicle for a flush mount and sound insulation is probably more suited to a warmer climate. Being in the north, I think Ill go with the indoor setup when I install one.