Stuart Turner Pump Pulsing When Shower Off.

[SimonG]

Strange one.
Stuart Turner Showermate, supplied by customer, fitted March last year.
All was well until August when they contacted me to say there was an issue with it pulsing when the shower is off.
I don't believe in coincidence, but at the same time as the issue arose they were having an extension built and I had nothing to do with the plumbing.
Went and had a look, cleaned filters, checked everything out and could find nothing.
Phoned Stuart Turner who advised me to turn hot and cold feeds off at the pumps. It stopped pulsing and they said there's a leak on the system.
It's a good install, pump on floor of cylinder cupboard, hot water is first feed to pump and cold is directly from loft tank.
Customer advised me they were happy to turn it on and off at the switch.
Been back today for something else and they asked me to look at it again.
Chucked 2 new check valves on the feeds to the shower, checked the mini vessel charge as good but still pulsing when off.
Turned hot water feed off at pump and it stopped pulsing.
Only other hot water outlets in house are kitchen sink mixer and cloakroom basin mixer. I isolated both but still kept pulsing.

Anyone any ideas?

 

[ShaunCorbs]

Would pressure test the external / outlet of the pipework

 

[Ben-gee]

leave the hot outlet isolated for a while, then when you re-instate if it runs and you hear water flowing to make up what’s benn lost , you know there’s a leak on that bit of pipework.

Could building work have damaged a pipe?

 

[SimonG]

There's less than 3 foot of copper pipe from the pump to the shower valve.

 

[Ben-gee]

Is it possible shower valve connections/pipe are leaking within wall?
I’ve just had one where ceiling got wet below and it turned out a female iron had split within the wall. ( this is because some clown had put about 40 wraps of ptfe onto the shower connector) - nothing visible until I started taking times off the wall.

 

[SimonG]

Unfortunately not, the connections to the valve are all fully exposed inside the cylinder cupboard.

Real head scratcher.

 

[Ben-gee]

Could it be a fault on the pcb? I’m guessing they have one.

 

[SimonG]

Could it be a fault on the pcb? I’m guessing they have one.

That's the real issue, I'm positive it's the pump yet Stuart Turner say it's the system.

 

[ShaunCorbs]

But if you turn the iso valves outgoing off it stops ?

 

[Ben-gee]

Try taking the shower valve off and putting 3/4 brass caps on it, then liven up system.
It could be some sort of crossover? Although I know they should be equal pressure ( resistance will be different in hot/cold supplies)
We are at the straw clutching stage!

 

[SimonG]

But if you turn the iso valves outgoing off it stops ?

Yes, isolate both it stops. Isolate hot only and it stops. Isolate cold and it pulses. All the pipe from pump to shower valve is visible in cylinder cupboard.

 

[SimonG]

Try taking the shower valve off and putting 3/4 brass caps on it, then liven up system.
It could be some sort of crossover? Although I know they should be equal pressure ( resistance will be different in hot/cold supplies)
We are at the straw clutching stage!

I'll give that a try.

 

[turnpin]

Hi SI......is the shower on the same floor as the pump ?and is the hot supply to pump from Essex or Surry flange...regards Turnpin