Part 1 (March 2025) discussed common problems encountered on the intake side of the pump and pump/ mechanical issues. Part 2 covers problems experienced on the discharge side of the pump.
Discharge Side Problems
Problem: compromised hose. Attack lines can be compromised for a number of reasons. From “burn through” when contacting hot coals or fire, to a burst hoseline resulting from being dragged across sharp objects, to hose failure from simple wear and tear, a compromised attack line can be a life-threatening condition. This situation usually requires the line to be backed out. Another cause of the attack line’s stream being compromised would be a valve being inadvertently opened such as someone kicking the valve handle open on the other side of a gated wye during an extended stretch operation. The result is the same in any of the above-mentioned scenarios: Water is discharging outside of the attack line before the nozzle, resulting in a loss of water to the nozzle team.
Solution: Getting a call on the radio from an interior crew reporting a loss of water pressure at the nozzle is a call that no driver/ engineer ever wants to receive. Fortunately, this problem can be readily diagnosed at the pump panel in most situations. Knowing is half the battle. Remember, water in any attack package is a closed system until it reaches the nozzle. Should water leave the system before the nozzle, the result is a reduction in available water at the nozzle.
So, what does this look like at the pump panel? Depending on how much water is leaving the system, whether from a burst/ burned-through section of hose or from an open valve (the gated wye example above), the result will be a drop in or fluctuation of pressure noted on the gauge of the discharge in question. Furthermore, when trying to throttle up to increase pressure to the affected line, the needle on the discharge will not respond normally and will start to “bounce” along with a fluctuation in rpm, especially if the pump is in psi mode. In most cases, the gauge will have difficulty raising and maintaining the discharge pressure because of water hemorrhaging outside the attack line prior to the nozzle.
If the line in question has any valves such as wyes, water thieves, etc. in play, those valves should be checked first and promptly closed. If there are no issues with open valves, or if the hoseline is preconnected with no such valves in use, then the most likely cause is that the hose has been compromised somewhere between the pump and the nozzle. This information should be relayed immediately on making the diagnosis. A backup line should be advanced and take over for the compromised line. The affected line should be backed out and replaced with a new section of hose.
Problem: blockages. There are several causes of blockages forming in attack lines. Kinks, debris in the line/nozzle, and delamination are all reasons an attack line can become clogged or blocked. The result is inadequate or no water being discharged from the nozzle. We will briefly examine each of these problems below. But first, we will discuss diagnosing a blockage.
As I noted in the previous section, the attack line is a closed system until water exits the nozzle. If a crew suddenly reports a loss of water pressure or volume with a fully open nozzle, one of two things may be happening. Either water is leaving the system somewhere else, as was discussed in the compromised hose section above, or the water is still in the system but is not making it in sufficient quantity to the nozzle for one of the several reasons discussed in subsequent sections of this article.
The astute driver/engineer can begin to diagnose this problem from the pump panel. If all