Mains feed

[PCAnimal]

I've had a new pressured system fitted inn the loft. From what i understand it uses cold pressure or flow to push hot water.
I've got a brand new 32mm mains into kitchen which then goes to 15 for whole house.
Now if you gush a toilet you lose pressure. The initial burst of hot is great in the shower but then tails off.
I'm thinking of solutions. I can't think how I can get the new feed up into the loft (ive got external side access).
The plumber suggested an accumulator.

Pressure is 5bar but I believe flow is key? Any ideas please?

 

[polesapart]

Any ideas please?

1 Measure your flow rate (bucket and stopwatch) at garden tap or kitchen sink
and also at at a bath cold tap.

2 Check that your mains stopcock is fully open and post a picture of it.

 

[Madrab]

If the system tails off then you may have a dynamic pressure problem.

That being said, whoever fitted the unvented HW cylinder should not have used a 15mm mains feed, most if not all need to be 22mm min, that will be specified in the MI. That should also have been highlighted as part of the initial survey which should have included a static/dynamic pressure and flow test to ensure the mains supply was suitable. I'd be getting the installers back in.

 

[PCAnimal]

Thank you I will get a bucket and try this. I am hardly at home at the moment

 

[FiremanT]

If the system tails off then you may have a dynamic pressure problem.

That being said, whoever fitted the unvented HW cylinder should not have used a 15mm mains feed, most if not all need to be 22mm min, that will be specified in the MI. That should also have been highlighted as part of the initial survey which should have included a static/dynamic pressure and flow test to ensure the mains supply was suitable. I'd be getting the installers back in.

I fitted mine to a 15mm supply (22mm mains is about 6M away), and it works okay. BUT it is on the ground floor in a bungalow. Being in a loft in a house is going to make it pretty much impossible on 15mm, I would have thought.

Is there no way of running 22mm to the loft?