Apologies for bringing up unvented systems - but I have searched and can't find an answer to my question.
My problem - in a nutshell the flow rate at showers etc isn't as good as I would have hoped.
My plumber (in retrospect I shouldn't have paid all the cash) blamed the flow on the mains, but didn't have a gauge to show me what it was and we left it at that as my builder would then replace the mains. (yes i know)
I subsequently had the mains replaced all the way back to the street assuming that rusted/crushed incoming pipework was the prob (replacement = 25mm? blue plastic all the way to the airing cupboard except for a tee to the garden/kitchen).
Static pressure is approx 5bar
A couple of questions.
1) Measuring flow at the (old) garden tap gives approx 22L/min. The tap is old and hisses / comes out as a jet akin to putting your finger over the end of a hosepipe. Am I correct in thinking this could be giving me an artificially low reading as it seems to be restricting flow (slightly) even when fully open?
2) I had a water softener installed after (chronologically- it is upstream!) the unvented system, but before the mains were updated. So as well as the 3.5 bar PRV combination valve with the system they installed a PRV before the softener. Is there a possibility of causing a problem if the first PRV is 3bar and the 2nd is 3.5 (ie the water pressure at the inlet to the combination valve is lower than the outlet rating) or will that make no difference.
3) While searching for answers I found many people talking of PRV's letting by. What is this? is it a failure of the PRV leading to higher pressures at the outlet or is it some other problem that I might have?
The instructions for the system say that min spec is 1.5bar-20L/min but performance won't be great. If my reading from the garden tap is accurate this is probably the cause. If so why is my mains flowrate so low with new pipework?
I have checked the pressure in the expansion vessel, cleaned the strainer in the combination valve and operated both check valves to ensure they discharge into the tundish and then close again.
Any suggestions appreciated
My problem - in a nutshell the flow rate at showers etc isn't as good as I would have hoped.
My plumber (in retrospect I shouldn't have paid all the cash) blamed the flow on the mains, but didn't have a gauge to show me what it was and we left it at that as my builder would then replace the mains. (yes i know)
I subsequently had the mains replaced all the way back to the street assuming that rusted/crushed incoming pipework was the prob (replacement = 25mm? blue plastic all the way to the airing cupboard except for a tee to the garden/kitchen).
Static pressure is approx 5bar
A couple of questions.
1) Measuring flow at the (old) garden tap gives approx 22L/min. The tap is old and hisses / comes out as a jet akin to putting your finger over the end of a hosepipe. Am I correct in thinking this could be giving me an artificially low reading as it seems to be restricting flow (slightly) even when fully open?
2) I had a water softener installed after (chronologically- it is upstream!) the unvented system, but before the mains were updated. So as well as the 3.5 bar PRV combination valve with the system they installed a PRV before the softener. Is there a possibility of causing a problem if the first PRV is 3bar and the 2nd is 3.5 (ie the water pressure at the inlet to the combination valve is lower than the outlet rating) or will that make no difference.
3) While searching for answers I found many people talking of PRV's letting by. What is this? is it a failure of the PRV leading to higher pressures at the outlet or is it some other problem that I might have?
The instructions for the system say that min spec is 1.5bar-20L/min but performance won't be great. If my reading from the garden tap is accurate this is probably the cause. If so why is my mains flowrate so low with new pipework?
I have checked the pressure in the expansion vessel, cleaned the strainer in the combination valve and operated both check valves to ensure they discharge into the tundish and then close again.
Any suggestions appreciated