Triton T90SR max inlet pressure

10 bar is for a mains fed shower. Definitely not for a pumped electric.

I agree with John that ground floor should be fine but if 2nd pump has the same issue then Id be willing to place a large bet that it's a plumbing issue rather than the shower

Edit: I don't suppose you are in a home with massive ceilings? 8 foot ceiling is about standard

It's all a big mess.

Installer should always supply. Your contract is now with the retailer for the shower and installer for the installation. If installer supplies then they are responsible for shower and installation.

You have no legal contract with Triton themselves.

Definitely not the solenoid. Tiny possibility it's the flow valve but much more likely a plumbing issue. I assume the shower has a direct dedicated feed from the cold water tank rather than tapping into a 3/4 inch pipe feeding other things like the toilet and basin. I'd expect the engineer would have flagged this a a possible reason if it was plumbed incorrectly

I suggest calling the installer & ask him how much head height would he guess. Assuming it's no way near 10m then I would call Triton again and ask to speak to the head engineer. You might have better luck with him.

Maybe a non return valve installed for some reason and faulty/sticking?, you could remove the supply at the shower (but needs cover removal), and check the gravity flowrate. Is this a new install or replacing a old shower with the existing piping?. Check the filter if you do remove the cover.

Strange one, only other thought is to ensure that its gravity fed and not from the mains.

An odd one. There doesn’t seem to be any logical reason to install a PRV.

I would keep the pressure on Triton to come up with a solution.

Are you certain the supply isn’t pumped elsewhere, or on mains?

If you remove the shower head and hose does the presentation change at all?

Has this new run of direct pipework from the attic tank just been installed?

I would be inclined to suspect the shower given what you describe and I would exhaust options with Triton before looking for a not so obvious plumbing fault.

Some photos and video would be great.

Did Triton replce the solenoid? I only ask because it was never going to be the solenoid. A solenoid can't fail in such a way to cause this. I'd be very disappointed in the engineer that thinks it could be the fault.

I would think it's either the flow valve (I don't think it is) or it's a plumbing issue & not the shower. I suppose another tiny possibility is it had a faulty motor & engineer mixed good with bad & put the original one back in instead of the new one.

The video doesn't show the water flow. I assume the flow is pulsating when it makes that sound?

I would shut off the water supply to the shower at the CWST, remove the supply at the shower, restore the supply and measure it, if, and it probably is > than 8 LPM then they will simply have to replace the shower, no arguments.

It doesn't t sound that healthy at any setting and does sound like a pump problem.

Like John says, I can't see it being a water pressure problem. The only time I saw water pressure from the tank being too much was in a Georgian type house in Dublin city. Shower was in the basement level & tank was several floors above. Each floor, except the basement, had really high ceilings. Slightly too much pressure for pumped electric but not enough for mains fed to function correctly in the summer months.

EDIT: Even easier and just as effective for measuremenr purposes, ensure power off at pull cord, turn the power selector switch to the cold position, turn the temperature control fully anticlockwise to the coldest position, remove the cover, two screws on top, one on the bottom, remove the filter cover & filter (first isolate the water supply) restore the water supply and measure the flowrate, there cannot be any arguments then re the plumbing. Also of course ensure the storage tank is refilling while using the shower.

It shouldn't shoot out more than the length of the shower tray or bath, if you think it will,you will need another pair of hands to open the isol valve while you hold a bucket against/under it for 30 secs, if this is too difficult then you will get a fair idea of the flowrate if it shoots out which it should with 0.5 or 0.6bar behind it.

Thats good, I would contact them and tell them that, also, if possible, email them the video, or show it to the next service person, they should then just replace the shower with a new one.

My neighbour got one of these installed just a year ago but had problems in getting it to run cool enough on setting 2 even with the temperature control fully anticlockwise so his installer repositioned the cover as per installation instructions and it seemed to run OK, I measured the flowrate just now and its only 6.4LPM fully anticlockwise and the control still has to be almost fully over now with a mains temp of 18.5C. On 1/2 power, setting 1, its set to one oclock which he normally uses in the summer, apart from that its running relatively quietly.

Sleeper12 will advise you on this, you opened it to check the filter and as you were at it you checked the flowrate??, if his advise is not to mention it then dont as your video is proof enough plus the fact that you are getting the designed full flow from the shower head.

The plot thickens!

Is this video recoded with the shower switched on?

From the sounds, there certainly seems to be flow in that pipe? And at pressure higher than gravity from an attic tank.

Is there a pump in the attic?

What is making the noise when you open the leaver valve?

It sounds like back pressure / water hammer. You can expect this type of noise on a pressurised system. You would open a leave valve slowly on mains water because of this. You should be able to open the leaver valve quickly when gravity (tank) fed

When you say it's fed from the tank, is it coming from a connection at the bottom of the tank? Some people see connection from the mains supply feeding the top of the tank & assume incorrectly that the water is coming from the tank. Having said that I would expect triton to pick up on it being mains fed if indeed it's mains fed.

What is the installer saying about the water hammer noise when using the leaver valve?

And yet the sound when closing the leaver valve does indeed suggest that there is a water pressure or plumbing issue.

It's a strange one.

What was the make and model of the old shower? Or is this a first time installation?

You are shutting off the water while running the shower? That's not a good idea if you are.

I think you said no noise from shower at full (cold) flow, switch the shower on, wait for 30 secs or so then switch off, check for noises.

Have you ever looked into the CWST to see if at normal level and filling from ballcock, also if the tank is clean?. Are there two outlets from the tank?, there may be one going to the HW cylinder, the other feeds the bathroom with the shower supply Teed off it, older tanks may just have one outlet but this in itself shouldn't cause any problems.

Any feedback from the installer or Triton engineer yet?

It’s not a protected title, anyone can refer to themselves as an ‘engineer’