Automatic irrigation timers and pressure

[Martin Pentreath]

Dear all,

I have put an automatic watering system in my garden from B&Q. After dithering over Hozelock and Gardena systems I found B&Q did their own which was cheaper, and seems to work very well. I've got drippers in pots and boxes and sprayers and sprinklers for the beds. So far so good.

Obviously the pi=E8ce de r=E9sistance for the lazy/absentee gardener is the electronic timer to give complete automation. The problem I am having is that the pressure of my water supply has always been a bit marginal. Without the timer attached to the tap the system works fine. With the timer screwed on the pressure suffers, and in particular the sprayers and sprinklers turn feeble and don't cover the area they should. The timer is B&Q's own =A325 cheapie:

the water is running the timer makes a high pitched whining noise, I guess the water is made to drive some sort of wheel for some reason which must take some of the oomph out of it. (Incidentally I don't use the separate pressure reducing fitting supplied with the system for obvious reasons.)

So the question is, is it worth splashing out for a different make of timer, or will I find the same thing happening?

Cheers!

Martin

[spamlet]

I have put an automatic watering system in my garden from B&Q. After dithering over Hozelock and Gardena systems I found B&Q did their own which was cheaper, and seems to work very well. I've got drippers in pots and boxes and sprayers and sprinklers for the beds. So far so good.

Obviously the pièce de résistance for the lazy/absentee gardener is the electronic timer to give complete automation. The problem I am having is that the pressure of my water supply has always been a bit marginal. Without the timer attached to the tap the system works fine. With the timer screwed on the pressure suffers, and in particular the sprayers and sprinklers turn feeble and don't cover the area they should. The timer is B&Q's own £25 cheapie:

the water is running the timer makes a high pitched whining noise, I guess the water is made to drive some sort of wheel for some reason which must take some of the oomph out of it. (Incidentally I don't use the separate pressure reducing fitting supplied with the system for obvious reasons.)

So the question is, is it worth splashing out for a different make of timer, or will I find the same thing happening?

Cheers!

Martin

Perhaps the clue is in that 'water saving' timer bit...

If it comes apart easily you might be able to remove any restrictor device: if the switched valves themselves are smaller diameter than your usual tap you are stuck though I fear.

Suppose if you didn't want the 'water saving' bit, you could modify a central heating timer and valve (if your supply is connected indoors), but if you don't have an old one lying around that would probably be more expensive than a garden version...)

S

[judith]

I do not think the problem is necessarily with the timer - when I first bought my Gardena irrigation system (quite a few years ago) there was a pressure control until which went between the tap and the drippers. I have now added a timer so I have:

tap---->timer----->pressure controller------>drippers

and it works very well.

[nightjar]

Before I gave up bothering with replacing the bits of my automatic watering system that had failed to survive the winter (usually about 25% of the fittings), I used to use four timers, each running a different part of the system at a different time, to overcome the problem of low pressure.

Colin Bignell

[Jeff Layman]

I have used a couple of different makes of pressure reducer (Gardena and Hozelock) and both of them tended to leak from the bleed valve. Both leaked worse when the initial kick came as the timers switched on. Maybe I was just unlucky. What experiences have others had with pressure reducers?

[Martin Pentreath]

Hi Judith,

It did come with a pressure controlling fitting, but this reduces the pressure so I've left it out, I don't see how anything could screw inline to increase the pressure.

Thanks to Spamlet for the suggestion. I can't see any way to take it apart, and anyway I think they only call it a water-saving timer because the timer concept means you only water for as long as you need, not because it's designed to restrict the flow.

Martin

[Owain]

Could you put a shower booster pump in front of it?

Owain

[Martin Pentreath]

I certainly could plumb one under the sink to feed the outside tap, can you use those things to boost the mains? I thought they were for to increase the flow from tank-fed showers.

[Owain]

Good point, should really be used from a tank not the mains. Might still sort the problem though.

Owain

[Chris J Dixon]

I have a Hozelock system, which includes this timer

has worked well for a couple of seasons so far. As far as I can tell, the timer is simply a motor driven valve. As it opens or closes a motor whirrs briefly. When in operation there seems to be no significant flow obstruction.

Chris

[tinnews]

They always fail on our water supply which is rather high pressure. I also don't believe they really reduce the pressure, not the ones sold for garden watering anyway.

For a couple of years I used washing machine solenoid valves with a cheap plug-in mains timer to time our watering. The timers sold for irrigation systems are ridiculously expensive in comparison.

However this year a search turned up some quite decent (I hope) battery operated timers for only £12 (from CyberConnect), so I'm using one of those this year.

[Martin Pentreath]

OK, many thanks Chris, that's useful information, I'll give it a go.

[judith]

Yes - apologies - I had not taken in the detail of your problem.

[Simon Stroud]

"nightjar .me.uk>"

Same(ish) here.

My Hozelok watering system is split into two with two timers. They turn on at slightly different non-overlapping times, so each half of the garden gets the benefit of full mains pressure and that's plenty to run all the outlets. Before I divided it I had to faff around adjusting all the drippers, sprayers etc to perfection so there was just about enough water to go round. Now it all works a treat.

Interestingly I haven't had to replace any bits due to frost damage. I do drain it all down as much as I can each winter, when I remember.

The Hozelok things that I have found to be particularly damaged by winter outside are the hoze spray handset things. I've got through several of them over the years.

Regards, Simon.

[Martin Pentreath]

I thought I'd better report back to the group for archival posterity.

Before spending cash on a Hozelock timer I thought I may as well try to work out what was going on inside the B&Q one. After a bit of knocking it about the whining noise stopped, I think it was just some sort of resonance going on inside. Also I found a nasty little filter, a dome of wire mesh within a very constrictive rubber washer. I've taken that out and the flow is now as good as without the timer on at all. Result!

Clearly the filter is to stop "stuff" getting into the innards of the device. I've no idea what sort of stuff might be floating about in the mains water supply, but I'm quite happy to take my chances seeing as I now have a properly functional system.

Cheers!

Martin