Hi guys, looking for a bit of help in finding the cause of a problem i have.
I've been using a Shurflow 100psi pump and a Varistream digital controller for the last few years with no problems, but just before Christmas something went wrong. When I stop the flow of water at the brush head, the pump runs for 3 or 4 seconds before cutting out, then when I restart the flow, the pump takes about 5 seconds to begin running. This means that when I re-start the water flow, I get an initial burst of water which trickles down to almost nothing before the pump kicks in, then the water flows normally until i turn it off and on again. Also, the flow-rate seems to be much less, I was always running the varistream at No5, but now I have to set it to max for the same flow rate as 5 used to be. I initially thought the pump was at fault, so I replaced it with a brand new one at the start of January, but that didn't solve it. So then I replaced the Varistream, still no joy. I then bypassed the Varistream altogether, and wired just to the pump, and this seemed to work ok, the pump kicked in immediately when I turned water flow on, but the pressure was still less than it should be. I checked all connections and all seem to be ok. Anyone have any ideas as to what could be causing this? Thanks.
Hi Barryy,
First Issue.
If you reduce your cut out pressure you may find that it will resolve itself somewhat. So if you are working on C reduce it to A and see if there is any difference. (Reducing the pressure too much will start the pump cycling, so you need to try a setting that will just prevent the pump cycling on your flow setting.)
This 'problem' is a number of things.
You say the first thing that is happening as you switch your flow off is that the pump continues to run for 3 or 4 seconds before the pressure builds up enough to your setting to cut the pump motor. That pressure has to go somewhere. We experienced the same problem with a replacement 100 meter length of minibore hose. It didn't happen immediately but became worse with time as the hose seemed to lose its strength and became stretchier. As the pressure built up the hose expanded slightly causing a reservoir of pressure. As we switched the tap back on, that pressure was released out of the 2 jets in our brush. The pump should switch off within a second of two at the most, not 3 to 4 seconds as you say.
If you take particular notice of each tap opening you will find that on occasion that initial spray of water will occur and then a dribble of water before the pump kicks in and your flow starts as you described. Sometimes you won’t have that dribble after the initial spray as the water flow resumes as the initial spray subsides. The gap between the initial spray and your flow resuming varies. The reason for this is that your Varistream controller pulses every 4 seconds (with ours) to see if the pressure has dropped. If you opened your tap just as the pulse has finished, then there is going to be a delay until the next pulse finds the pressure has dropped and switches the pump back on. So the length of the delay will depend on which part of the pulse cycle you opened you tap on.
I also noted with this length of hose that the reel became tight under pressure with the expanding hose and that I had to continually unwind the hose and re-layer it. If I re-layered it under pressure the hose would go lose when the pressure was removed and if I re-layered the hose with no pressure then the hose reel became tight and I couldn't unreel the hose easily.
My son still has a hose reel with some very stiff minibore hose and swopping the hose reels over solved the problem without any other changes.
It’s not the pump, Varistream or any connections – it’s your hose. I replaced mine even although it was about 8 months old and don’t have the problem much now. Unfortunately we love the flow characteristics of the stiff hose, but when the water is cold it’s a nightmare to work with.
If you can, try to find another helpful window cleaner locally and see if his hose reel makes any difference on your system.
It could also be that you have a problem with the hose from the pump to the van port (if you have one) and/or from the van port to the hose reel. So don't forget to check those out as well.
Second Issue.
Yes, we also find that as the water temperature drops the water flow out of the brush head is less. Our water in the tank in the van is 7 degrees at the moment – it becomes ice when it freezes which is a solid. Your pump has to work harder as the viscosity of the water becomes less. (Cold water is less fluid than warmer water.) You will also find that if you unreel your 100 meters of hose the flow will be better than with it fully coiled up.
During the Christmas break I rigged up a diesel heater on a test bench to see what I would need to do to work with hot water.
At that time the water in the van’s tank was 9 degrees and we raised the temperature of the water to 35 degrees at the brush head. Normally I work with a flow of 5 on my digital Varistream, but with warm water that same flow setting pushed the flow from the jets across the road. (The pole was lying up-side down on the driveway.) I found that a 5 setting delivered the same flow of cold water as a 3 setting did of warm water.
I also noticed that I needed to reduce the cutoff pressure as the warm water was making the hose on the reel softer and stretchier and was producing similar symptoms we experienced with that previous lot of hose.
Hope you can make sense of this.