[Ken_Long]

I wonder if anyone can shed any light on this?

I have a digital variflo controller, controlling a Vyair 5 lpm pump. The pump draws from a 400 litre tank, and then pushes the water through an 11 litre DI vessel, and then on to the hose reel (100m of microbore). What I'm finding is that the flow rate fluctuates during the day: it can start off a little weak, pick up and be fine, then tail off, then pick up etc. The battery (85 a/h) is charged.

I have measured the flow rate at various stages in the system today:

1. From the end of the microbore hose, it takes 35 seconds to fill a one litre bottle.
2. From the end of the DI-to-reel hose, it takes 20 seconds to fill the one litre bottle.
3. Direct from the pump (not passing through the DI) takes 20 seconds to fill one litre.
4. With the microbore pulled right out, 35 seconds.
5. Connected from the DI to a standard Hozelock 1/2" bore garden hose, 35 seconds.
 
I have recalibrated the variflo.

It appears to me that the problem lies with the hose or reel. It appears undamaged, but is a couple of years old now. Could it have ruptured inside and be partially blocked? It has had a few vehicles over it in its time! Would I be better to switch to a minibore hose? Of course, maybe the pump is getting on and can't push the water out through 100m of pipe. The system has worked fine in the past, and it is only in recent months that it has started becoming a little erratic.

Any constructive suggestions appreciated.

[Matt.]

Hello ken, I got as far as the vyair pump when reading .......... There is ya problem.

[Dave Willis]

Any evidence of air (spurting at the brush head). Check and clean any connections in the wiring.

[Matt.]

I have read it all now mate, similar set up to mine from tank ➡️through pump ➡️11L di bottle into hose, I tried a few bits from vyair and it caused me to go grey .......... Never again mate

You may also find the pump will alter it's flow depending on what height your pole is at.

I consider vyair to be a swear word and the mods should block/amend to shurflo

[Spruce]

The more you ask the pump to do, the slower the flow as there is more resistance. A pump has to work harder to push water through the hose which is wound onto the hose reel than if the same hose was pulled out straight along the ground.

In the early days Williamson pumps refused to warranty a Shurflo pump that had been used with Microbore or Minibore hose. They originally stated that they should only be used with 1/2" hose because of the extra stress this puts on components.

I have a couple of jobs where the hose is completely wound off the hose reel. Water always flows quicker on those jobs

Water flow will also increase when the water is warmer than when its colder as its viscosity changes. Water at 0 degrees is a solid.   

What you have experimented with is totally normal - it will happen to any pump.

Your battery will also work better when it warms up. A cold battery can loose as much as 25% of it's power. This is why batteries tend to fail in the cold months. They are not only down on output power, but the starter motor of a cold engine takes a much higher current (amps) from the battery) to start.

Batteries also get warm when charging or discharging. If the warmth is in that area where performance improves, then you will notice it.

[Spruce]

I have read it all now mate, similar set up to mine from tank ➡️through pump ➡️11L di bottle into hose, I tried a few bits from vyair and it caused me to go grey .......... Never again mate

You may also find the pump will alter it's flow depending on what height your pole is at.

I consider vyair to be a swear word and the mods should block/amend to shurflo

Like most things they were made out to be the best thing since sliced bread.  They were much cheaper than Flojets and Shurflo, but these days they aren't much cheaper than a Shurflo. I'll stick with what works for us.

We have stuck with Shurflo and they have done us proud. We have 3 working pumps that are all over 8 years old.

[Matt.]

Yes shurflo is the one, it's about reliability.

I tested the grass over the fence and climbed back over sharpish 

[Ian Lancaster]

Erratic flow rate??

It's an age thing, or so my doctor tells me.......

[Ken_Long]

Many thanks for all your answers!

I have checked all the wiring, and all connections are solid.
I appreciate that the battery and flow can be affected by temperature, but I have been having this issue with a fully charged battery randomly through the day, even in the summer!

So it looks like it is the pump. I'm going to double check today, by meeting up with a fellow window cleaner, and trying my reel on his pump and vice versa, just to confirm my suspicions.

If after that I have to replace the Vyair pump with a Shurflo, where would you suggest for the best price?  Soap National are £87.60 delivered, Cleaning Spot are £90 delivered and as always, Window Cleaning Warehouse are the most expensive at £108.30!

Any other suggestions?

[Matt.]

It's the pump mate I had all this with them working not working trickling flow gushing out

I bought 2 pumps from aqua solutions I can't remember off top I me head shurflo 6.8 lpm done me both for £150, infact al be getting another 2 next week off him.

[SeanK]

Ken just be careful when buying your Shurflo as you can get a 5ltr per minute and a 7ltr per minute if its under the £80
mark its usually the lower flow rate, stick to the higher flow model.

[Ian Sheppard]

The more you ask the pump to do, the slower the flow as there is more resistance. A pump has to work harder to push water through the hose which is wound onto the hose reel than if the same hose was pulled out straight along the ground.

In the early days Williamson pumps refused to warranty a Shurflo pump that had been used with Microbore or Minibore hose. They originally stated that they should only be used with 1/2" hose because of the extra stress this puts on components.

I have a couple of jobs where the hose is completely wound off the hose reel. Water always flows quicker on those jobs

Water flow will also increase when the water is warmer than when its colder as its viscosity changes. Water at 0 degrees is a solid.   

What you have experimented with is totally normal - it will happen to any pump.

Your battery will also work better when it warms up. A cold battery can loose as much as 25% of it's power. This is why batteries tend to fail in the cold months. They are not only down on output power, but the starter motor of a cold engine takes a much higher current (amps) from the battery) to start.

Batteries also get warm when charging or discharging. If the warmth is in that area where performance improves, then you will notice it.

I would concur with Spruces comments, reading through you are getting between 2 and 3 LPM from the pump, although the article does not mention what flow setting you are using.  The 5lpm is measured at the pump outlet in open flow ( no restriction) as soon as restrictions are added EG hose, Jets, DI the flow rate to the brush will be reduced by the restrictions.

While air and or a blockage in the reel may be part of the issue, have you considered having the pump after the DI ? The pump would then be pulling water through the DI rather than pushing and this may help the flow rate.

This link gives  further info on pressure dynamics https://www.linkedin.com/pulse/pressure-dynamics-wfp-system-ian-sheppard?trk=mp-author-card

[Ken_Long]

Ok, I tried the pump after the DI, the flow was even worse!

I have bitten the bullet and just ordered a Shurflo from Williamson pumps. This one in fact: http://www.williamsonpumps.com/8002-793-238-614-p.asp

They seemed to have the best prices, and this one is the 7 lpm one (for a couple of quid more than the 5 lpm).

I hope this sorts it out, I'll let you know how I get on...

[Dave Willis]

http://www.agratech.co.uk/search.php?mode=search&page=1

I thought this one looked interesting  http://www.agratech.co.uk/Shurflo-8000-543-138-12v-Pump-100-PSI-6.2-Ltrs-Min-1.4-GPM-8000-946-1381.html

[Matt.]

That's the place Dave

[Spruce]

Ok, I tried the pump after the DI, the flow was even worse!

I have bitten the bullet and just ordered a Shurflo from Williamson pumps. This one in fact: http://www.williamsonpumps.com/8002-793-238-614-p.asp

They seemed to have the best prices, and this one is the 7 lpm one (for a couple of quid more than the 5 lpm).

I hope this sorts it out, I'll let you know how I get on...

Price is + VAT so 20% more expensive.

http://www.agratech.co.uk/search.php?mode=search&page=1

I thought this one looked interesting  http://www.agratech.co.uk/Shurflo-8000-543-138-12v-Pump-100-PSI-6.2-Ltrs-Min-1.4-GPM-8000-946-1381.html

Price includes VAT

[Matt.]

http://www.agratech.co.uk/search.php?mode=search&page=1


Phone these up, 2 x pumps £150, delivery is a out £6.

[simon w]

Don't want to state the obvious but have you looked at the pumps particular strainers for debris?  If your tank picks up some muck then you might occasionally need to remove the strainer clean it out and refit . Stronger flow rates and less pressure on pump and draw on batteries.

[Ken_Long]

Quick update: super prompt delivery from Williamsons. Fitting straightforward, and with no other changes to the system I now have a proper spray of water coming from the brush head! It makes life so much easier...

[Spruce]

Quick update: super prompt delivery from Williamsons. Fitting straightforward, and with no other changes to the system I now have a proper spray of water coming from the brush head! It makes life so much easier...

That's good.

One other thing though. Have you got an inlet filter?

I prefer the bayonet fitting type
http://www.williamsonpumps.com/255-215-1325-p.asp

Hose fitting straight
http://www.williamsonpumps.com/234-2926-1421-p.asp
 or
Hose fitting elbow
http://www.williamsonpumps.com/234-3926-1517-p.asp