Heater Booster Maintenance

heater booster stopped working during the winter witch sort of sucked, so i decided to take a crack at this thing and see what was up. Boy was i shocked. Gaskets had melted to the body so bad i thought they were missing entirely and thought some one forgot to install them. Did roughen up the surface a bit as it took forever to brake it away from the shell as it was really hardened but i plan on sanding down the surface a bit later to make it more smooth.
Not to mention all the white crust of calcium/ rust build up that was everywhere.

Took some photos but i will post more as i get closer to finishing up. I am waiting on a few parts, will be replacing the fuel metering pump screen and blower motor.

Thanks for sharing i have two heaters like that, both of mine are not working. I been tempted to take one out and see what's up with it. Do you think its possible the heater can be removed and bypassed so the van could be drivable? Yes please Include more pics if you can thanks.

There use to be a scan tool that could be plugged into heater while it was out of the vehicle to bench test. There is this one too https://www.eberspaecher-na.com/products/service-diagnostic-tools.html

Yes for sure the heater can be bypassed at heater booster using a U-shape by pass hose to re direct the coolant backup mean while, however if you have rear Aux heat this method will probably put it out of service till you hook everything backup. There are two hoses that run down on the firewall by the driver side that deliver the coolant down to the booster. Motorcraft makes coolant bypass hoses. Such as this. I will also take a picture of the connection tomorrow for better visual.
https://www.carid.com/motorcraft/coolant-bypass-hose-mpn-km4490.html?singleid=1399008633

The process is fairly simple for dissembling the unit it self, This was the first time i did it so im sure you can handle. i just took a lot of photos and marked where all the nuts and screws went. Downloading the repair/service manual will certainly help.
https://www.butlertechnik.com/downloads/Eberspacher_Heater_D5WS_Workshop_manual.pdf

I had tested the heater on my van with Xentry before the repair so that sort of hinted to what was going on. But i would be interested to know how these scan tools would work with the units off the vans. If you can find someone with Xentry you can perform a functionality test.

I will provide OE part numbers in the coming days for most of all the parts required for these units, seems like the ones in WIS are out of date.

Heres a photo of the coolant lines underneath, from what i understand the lines circled in red are what feeds in to the heater booster, and lines in yellow are from the rear aux heater. If you dont have the rear heat, connecting the coolant lines together with a by pass hose in the red circle will by pass the booster. Hope thats helpfull sorry if it sounds confusing.

gulum1804,

Could you do me a huge favor and take a few pictures of the other end (the engine end) of the pipes going down to the heater? My Sprinter did not come with the heater option and I am trying to add it in from donor vehicle parts. I wasn't the one who removed the pipes so I haven't a good picture of where they mount up top and how the hoses are plumbed up top.

Thanks!!!!

rollerbearing said:

gulum1804,

Could you do me a huge favor and take a few pictures of the other end (the engine end) of the pipes going down to the heater? My Sprinter did not come with the heater option and I am trying to add it in from donor vehicle parts. I wasn't the one who removed the pipes so I haven't a good picture of where they mount up top and how the hoses are plumbed up top.

Thanks!!!!

Click to expand...

Here ya go, i did the best i could at the moment.

Exactly what I needed!!!

Can't thank you enough!