It's worth phoning the manufacturer anyway.
Had one recently (Range Tribune) that was leaking from a failed weld.
Couple of years old and customer had never had it serviced - Range replaced it free of charge anyway.
hth
I didn't know that - not sure how you could patent one anyway as similar set ups have been around for years.
maybe it's to do with the diffuser design ?
An accumulator is just a large expansion tank.
Seen a few of these fitted with unvented cylinders and they work well.
there's some good installation diagrams at www.gah.co.uk
hope this helps
Can you disconnect the blue mdpe in the airing cupboard and check what flow rate & pressure you're getting there.
At least then you might get an idea where the problem is.
How many lpm do you get from your kitchen cold tap ?
Also some water softeners can be quite restrictive - bypass the softener and see if there's a difference.
If you haven't already got the pump take a look at the Stuart Turner website.
They're pumps are very good and they allow / recommend a hot water take off from the horizontal hw supply.
Might be worth a look.
In my experience, when there's a leak from the end of the prv cartridge, the cartridge will be seized into the housing and can be a real pig to get out.
Rusti,
good luck with your kitchen install.
There is a book you might find useful, I've put a link to it below
http://www.amazon.co.uk/How-Win-Friends-Influence-People/dp/0749307846
hth
Sounds like you have a one pipe system.
Best to repipe as a two pipe system but in the mean time put some cleaner in (x800 or similar) it might make a difference but wouldn't hold my breath.
Try turning your room thermostat down after the heating's been on for a while & see if it bangs then ? - some motorised valves can make a noise when closing.
A check valve on the hot wouldn't be for backflow prevention, it's to stop mains pressure water going through the tap and up the hot supply into storage cistern causing overflow to run.
A flap type nrv will give hardly any restriction to flow.