Removing mid heater, not confident about bleeding coolant system

[dbsoundman]

Hi all, my bus has 4 heating systems: the front defroster, the drivers heater, a mid bus underseat heater, and a rear underseat heater. I had originally planned on keeping both underseat heaters, but I’m having some trouble with my webasto coolant heater, and I also forgot that the underseat units are really loud, so now I’m considering taking out the mid heater. The heaters all run in series, so I would just need to put in a short connector to remove the mid heater.

Problem is I have always been leery of bleeding coolant systems, don’t ask me why. So far I’ve identified one shutoff valve and one bleeder on my bus in the front, but I don’t know for sure how to bleed the system properly. The radiator has a sight glass on it so I can see the coolant level, and the overflow tank is usually empty when the bus is cold because it’s a closed system. I’ve read some things about parking on a hill to bleed the system but I live in like the flattest part of the world, so that’s not really an option! [emoji1787]

If I’m just removing one heater am I likely to introduce a lot of air into the system? Just trying to get some confidence, I’m worried about getting halfway to anywhere, then overheating.

[Timeline]

The engine water pump will help, I warmed up the bus and once I loosened the hose at the seat heat exchanger the air hissed out and warm coolant began to flow. The seat was not bolted to the floor so I was able to make that fitting the highest point in the system....



Hope it is that easy for you too.




John

[s2mikon]

You should have 2 valves to isolate the heater loop from the rest of the system. Close both and remove the offending component and re open both valves. You should also have a booster pump inline turn it on and restart your engine. Pinching the hoses close to the heater can help too, just don't over pinch them with a huge c clamp and damage the hoses.

[magnakansas]

If the issue is noise, keep the heater, change the fans.

William

[dbsoundman]

Originally Posted by magnakansas

If the issue is noise, keep the heater, change the fans.

William

I think I have one fan that doesn’t run at all, and one that doesn’t run well, out of four total. Pulling one heater would give me two good but very loud fans. Are there any good alternatives for the original fans?

[magnakansas]

quiet 12v fans... I have read more than one person using some sort of computer cooling fan for this.

I am sure there are hundreds of 12v fans out there... just have to find out what makes a quiet fan and a loud fan..

then begin looking and asking.

I have the big ol noisy ones myself for now..... squirrel cage fans are usually pretty quiet.. that is what is used on most cars for underdash heaters...

william

[cadillackid]

turn off the engine valves.. do this removal when the engine is dead cold.. remove the radiator cap to release any negative pressure on the system..



take a piece of 1 inch heater hose about 2 inches long and slit it make 2 of these..

go to your bus heater.. slide your slit piece of hose over the line going in and out of your mid heater a few inches back.. put aa pair of vice grips on your sleeve and clamp down.. not crazy hard but enough to flatten the sleeve and the line underneath.. do this on the incoming and outgoing lines..



wet down the heater lines on the outside with coolant or WD-40 (wet rubber cuts 10X easier than dry)..


now cut the heater lines off of the heater and immediately raise each line up as high as you can.. (have your new splices read)...

connect your 2 heater lines together, clamp and remove vice grips and sleeves..



if done right you lose very little coolant and suck in very little air..


note how much coolant you lost on the floor or wnt into your catch pan and replace into the bus reservoire, open the heater valves. put the radiator cap back on, start it and warm it up till the engine fan blows warm.. leave the heater valves open and if you have a booster pump have that on.



dont use your webasto until you have driven the bus around awhile to work the air out.. air in the lines is Toxic to webasto's

[cadillackid]

Originally Posted by dbsoundman

I think I have one fan that doesn’t run at all, and one that doesn’t run well, out of four total. Pulling one heater would give me two good but very loud fans. Are there any good alternatives for the original fans?

ditch the noisy crappy underseat heater, put in a Jegs heater.. use a variable speed controller for extra low / quiet fan speeds for at night..



unlike computer fans you will be able to have Lots of heat when you want it.. computer fans are quiet but are very low pressure.. they work if you only want to use that unit at night in light heating conditions..

[dbsoundman]

Originally Posted by cadillackid

turn off the engine valves.. do this removal when the engine is dead cold.. remove the radiator cap to release any negative pressure on the system..



take a piece of 1 inch heater hose about 2 inches long and slit it make 2 of these..

go to your bus heater.. slide your slit piece of hose over the line going in and out of your mid heater a few inches back.. put aa pair of vice grips on your sleeve and clamp down.. not crazy hard but enough to flatten the sleeve and the line underneath.. do this on the incoming and outgoing lines..



wet down the heater lines on the outside with coolant or WD-40 (wet rubber cuts 10X easier than dry)..


now cut the heater lines off of the heater and immediately raise each line up as high as you can.. (have your new splices read)...

connect your 2 heater lines together, clamp and remove vice grips and sleeves..



if done right you lose very little coolant and suck in very little air..


note how much coolant you lost on the floor or wnt into your catch pan and replace into the bus reservoire, open the heater valves. put the radiator cap back on, start it and warm it up till the engine fan blows warm.. leave the heater valves open and if you have a booster pump have that on.



dont use your webasto until you have driven the bus around awhile to work the air out.. air in the lines is Toxic to webasto's

Excellent advice. I’m thinking we will definitely remove one of the two heaters, just not sure which one. I did realize the heaters are in parallel, the webasto is in series. Still the same principles apply.

At this point I’ll keep the webasto until I have a compelling reason to do otherwise, but I’m also not in as much of a hurry to fix it. I got a Mr Buddy heater so I can work out there in the cold weather (with all the appropriate precautions of course). I was feeling stressed about trying to fix the webasto over the winter, now I can take it a little easier.

[dbsoundman]

Originally Posted by cadillackid

ditch the noisy crappy underseat heater, put in a Jegs heater.. use a variable speed controller for extra low / quiet fan speeds for at night..



unlike computer fans you will be able to have Lots of heat when you want it.. computer fans are quiet but are very low pressure.. they work if you only want to use that unit at night in light heating conditions..

I’m thinking the bus heater will be mainly for heating on the road. Even then, my wife said we should just ditch both bus heaters, suck it up if we’re traveling in cold weather, and get a diesel heater. So we shall see!

[cadillackid]

ewwww mister buddy.. worst heater ever.. CO and moisture.. maybe as a work heater? I guess but i hate open flame stuff unless im in a Big wide space like a garage

[dbsoundman]

Originally Posted by cadillackid

ewwww mister buddy.. worst heater ever.. CO and moisture.. maybe as a work heater? I guess but i hate open flame stuff unless im in a Big wide space like a garage

It’s a temporary solution, not permanent. Definitely going diesel heater or something webasto heated long term. The Mr Buddy is good for working and our potential trip south for a week or so over the winter.

[Timeline]

Originally Posted by dbsoundman

It’s a temporary solution, not permanent. Definitely going diesel heater or something webasto heated long term. The Mr Buddy is good for working and our potential trip south for a week or so over the winter.

CO2 detectors are inexpensive, if you don't have one please get one!


John

[EastCoastCB]

Originally Posted by dbsoundman

I’m thinking the bus heater will be mainly for heating on the road. Even then, my wife said we should just ditch both bus heaters, suck it up if we’re traveling in cold weather, and get a diesel heater. So we shall see!

I drove a bus from kentucky to fl in November. It was 11* in kentucky.
The heaters were shot and didn't work. It was the most miserable drive of my entire life. Icicles inside the friggin bus hanging from the leaky roof hatches!
Keep heat up front behind the driver seat or somewhere it can warm the front up a bit. Keep the defrost for sure.

[o1marc]

A computer fan typically runs around 1500rpm and moves around 60cfm, the squirrel cage bus heaters put out 275CFM @1600rpm each. Huge difference if heating a large space the size of a bus. Rather have too much and not need it , then need it and not have enough.

[jimmythomas]

A good source for fans on the bus heater is your local pick-apart yard. Take a 12 volt power supply with you ( wires from a cordless tool battery pack ) and put power to various cooling fans you find in the yard. I was using a complete fan assembly from something as a hood prop and was very impressed by the quality of the fans -- very smooth and quiet. I think the price for cooling fans was $20 each.

[cadillackid]

engine cooling fans for bus heaters? they are usually pretty noisy.. the issue with underseat bus heaters is in an attempt to make them omni-directional they use a Blade fan and not a squirrel cage. . the heater core is in the top of the machine and the fans suck the air down and blow it at the floor which spreads it out across rows of seats in front of and behind the heater as well as sideways.. these fans are noisy even on low speed..

the heater core is also horizontal which usually collects lots of dirt and grime so its clogged up. the Jegs type heaters use a dual-wheel blower which moves tons more air and its quieter..



you can install a variable speed controller unit on these blowers as well so you can turn the blower speed down very low..



with computer fans you are stuck at the low volume always.. I like the choice of running my fan speed up on high.. for instance yesterday it was 19 in the morning and I was working in my mobile office.. I had that heater cranked to high speed and it still couldnt out-run the webasto.. I used a second heater up front and had the bus up to a comfortable 80 in no time despite the cold winds.. (all stock bus).. if i had been wanting to sleep at night I would have turned the blower control down to a pretty low setting.. one of the variable speed controls I have (but havent installed) even has external inout capability (0-10V drive and 4-20ma ) so you can use a computer to control it..



the Fan speed control in my new Pickup truck has a CAN input to it.. would love to get one of those to use for the bus heaters..