Adjustments to the BN4 heater

Ever since the BN4 install, the exhaust has been a bit over whelming. It was consistently dark and soot would start building up in the exhaust pipe to the point that it wasn’t able to produce much heat at all. The person I bought the heater from (quite experienced in these units) stated clearly that the fuel pump had already been adjusted to supply the correct amount of fuel to the unit. Not wanting to take the fuel pump apart if at all necessary, I looked at the intake side of things. My install involved 3/4″ pvc tubing to route the combustion intake to the exterior of the bus. Chatting with some friends a bit, it was stated that it was probably a lack of oxygen that was causing my nasty exhaust output. So finally, I increased the size of the intake pvc tubing. It is now 1 1/4″ diameter pvc and there is one less 90 degree angle in the design.
Results were positive, but not as drastic as I thought they might be. The exhaust is much clearer now and the heater warms up faster. Both very good things. But there is still a bit of black in the exhaust and I am not sure if the heater needs more adjustment, or my expectations. I took a short clip that I’ll post to see if I can get some opinions from others about it. Other than that, the recent dip into single digits has made the BN4 a very welcome addition to the ride….even with that noisy fuel pump clicking away.

2 thoughts on “Adjustments to the BN4 heater

  1. The build-up of soot continues. It doesn’t seem to be as quick to accumulate, but I still have to take a hammer to the exhaust to break it up and get it out if I run it for 3 or 4 hours during any given day. I may still need to look at adjusting the fuel pump.

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