Water spurt then delay - what's the cause?

[SilverComet]

Hi,

After many plumbing issues (PRV, ruptured tank, pump being set too high) we've gotten our plumbing back to normal, that is until we tried the taps, at some point in the 2 month plumbing fiasco we've either gotten an air block or we've had something break. We have water when turning the tap for 1 maybe 2 seconds at what feels like full pressure, then nothing for 10 or 15 seconds till the pump kicks in.

It's worth noting the lowering in pressure was weeks before our major issues and was working for a good 6 weeks before everything was turned upside down.

Does anyone have any ideas? I've tried raising the pressure, it worked for about 10 minutes then it was back to before.

[MtB]

36 minutes ago, SilverComet said:

Hi,

After many plumbing issues (PRV, ruptured tank, pump being set too high) we've gotten our plumbing back to normal, that is until we tried the taps, at some point in the 2 month plumbing fiasco we've either gotten an air block or we've had something break. We have water when turning the tap for 1 maybe 2 seconds at what feels like full pressure, then nothing for 10 or 15 seconds till the pump kicks in.

It's worth noting the lowering in pressure was weeks before our major issues and was working for a good 6 weeks before everything was turned upside down.

Does anyone have any ideas? I've tried raising the pressure, it worked for about 10 minutes then it was back to before.

 

Ok, I find your post rather confusing. Can we clarify the fault please?

You seem to be saying when you turn a tap ON you get water for two seconds, then it completely stops for ten seconds, then the water starts again. Yes?

What happens next? Does the water flow normally or does it stop again after a further two seconds an continue to cycle ON and OFF?

What make and model of pump is it? Is the same behaviour present and every hot and every cold tap? Have you checked?

[SilverComet]

Apologies, I always want to list every detail then it ends up confusing.

We turn on any tap at all, or flush toilet, and get a 2 second burst of water, which then stops for about 10 seconds before the pump kicks in, it is a constant stream after that. Unless we flick the tap off and on, in which case we have a 10 second wait again.

 

Edit:

We have a Johnson 2.9 WPS pump btw, can't see a label on the accumulator. No pressure gauge either, last time I turned it down in quarters until we had a steady stream out the tap.

Edited January 22, 2018 by SilverComet

[WotEver]

Sounds to me like a sticky pressure switch, or just maybe a restriction close to the pump?

[MtB]

Hmmmm I'd say the 2 second burst is the accumulator emptying itself until the pressure reaches zero, instead of the pump switching ON when the pressure falls to the switching pressure which will be about 07bar. 

As Tony just said, a jammin' pressure switch. 

You should give your pump a name. You could call it Bob Marley.

Why? Because its always jammin'... Boom boom!!

[Tony Brooks]

Probably time or a remote pressure switch like a Square D and be done with the orrible micro-switches in the pump.

[smileypete]

Try a forum search, eg pressure switch problem, this has come up many times before...

[SilverComet]

2 hours ago, smileypete said:

Try a forum search, eg pressure switch problem, this has come up many times before...

Apologies Pete, I did plenty of searching around prior to posting. As I had no idea what part was causing the issue the entire point was I needed help to know what to look up.

[cuthound]

When I saw the title of the thread I thought the OP was seeking medical advice regarding his prostrate 

[WotEver]

44 minutes ago, cuthound said:

When I saw the title of the thread I thought the OP was seeking medical advice regarding his prostrate 

Prostate sir, Prostate. 

Unless you were suggesting he was lying inert on the ground. 

Or as Hilda Baker once said, “He was lying, prostitute at my feet”. 

[Chewbacka]

My mother-in-law told me that I should not eat peanuts from the little bowl on the bar as they contain foetus parts.   Took me a while to work out she meant fecal matter.

[cuthound]

1 hour ago, WotEver said:

Prostate sir, Prostate. 

Unless you were suggesting he was lying inert on the ground. 

Or as Hilda Baker once said, “He was lying, prostitute at my feet”. 

Quite correct. I blame it on my spill chucker. 

[smileypete]

On 1/26/2018 at 12:58, SilverComet said:

Apologies Pete, I did plenty of searching around prior to posting. As I had no idea what part was causing the issue the entire point was I needed help to know what to look up.

Sorry was on the mobile at work and didn't have time to say more. The forum search is a bit broken in that it defaults to searching the current topic and not the whole forum - the tech bods are unwilling or unable to fix it.

Nevertheless it sounds like the pump pressure may be too low and/or as said there's a fine bleed hole in the pressure switch that can get gunked up.

It s should be possible to measure the pressure with the 'tyre' valve under the black cap on top of the accumulator. Generally the accumulator pressure should be around 14psi/1 bar with pump isolated (off) and cold taps open. Then with pump powered, taps closed and pump cycled off the pressure in the accumulator should have risen to around 28psi/2 bar, this reflects the cut off pressure of the pump.

Systems with a calorifier should also have an expansion vessel near the calorifier, this looks like the accumulator (in fact it's the same item used for a different purpose) and it should be pressurised to around pump cut of pressure of 28psi/2 bar with pump off and hot taps open.

Systems with a 4 bar calorifier can use a higher pressure pump but even so it might be best to keep to one with a 28psi/2bar cut off pressure to reduce stress on the calorifier as they're costly if they develop a leak.

A common error is buying a pump with too high a cut off pressure, but most can be adjusted down OK. Fitting a suitable pressure gauge, usually up to £10 from the likes of Ebay can make diagnosing problems much easier, they often come with a 1/4 BSP male fitting and need a BSP adaptor to get to the more useful 1/2" BSP size.

If the pressures check out OK and the pump still misbehaves then one way to avoid disembowelling the pump is fit and external 'square d' type pressure switch as Tony says, cost around £20 or there's some cheaper copies from around £10, eg:

https://www.ebay.co.uk/itm/Well-Water-Pump-Parts-Double-pole-Adjustable-Pressure-Control-Switch/172785420015

Edited January 28, 2018 by smileypete