I dont know if the boxer has the same type of set up as the chemspec494, but with our 494 if the waste tank debri filter is blocked then the waste water cannot drain through correctly, if this happens the problem that will occour is that the blower will suck in air from the nearest source, as the blower is designed to work in a cycle, i.e by drawing air through the bottom of the waste filter, if the filter is blocked up then it cannot draw air correctly through the bottom of the filter hence, having to draw air from above the waste filter, as the waste water has nowhere to fall then it will be sucked directly through the blower filter and clog it up, blow it out of the exhaust. You must keep the filter clean at all times to avoid this happening, this could cause serious damage to the blower as waste water carrying chemicals, especially any chemical carrying enzyme, pog or suchlike will strip the blowers of all grease oil that allow it to work freely, hence, a noisy, sticking blower that will not last a long time, again i dont know about the boxer, but the 494 has a tap at the front of the machine to allow you to pray WD40 into the blower suction that oils and strips the blower of water residue, as a rulewe always spray our at the end of each day or when we are on a big job that requires the use of chemicals as described above we do this process every 30 minutes as even chemical fumes hot water steam can be drawn into the blower again having the same effect.
regards Dave ADL