Poor pressure on a megaflo??
- Thread starter davecon1
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J
just-thinking
Gravity...ok not going back to school days....but take a look of my wife known her for 25 years and now gravity has happened.
so get your installer to sort it out or i will send my wife.
pay for some pressure reduceing valves where pressure is excessive,did you ask installer to provide always same pressures,i think not as impossible.
what drought.
so get your installer to sort it out or i will send my wife.
pay for some pressure reduceing valves where pressure is excessive,did you ask installer to provide always same pressures,i think not as impossible.
what drought.
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The throbbing shower - could be because it has a thermostatic cartidge designed for (your previous) gravity suppy to it?
In average pressure situations with an unvented HW cyl you wouldn't expect to notice a huge difference in tap behaviour upstairs and down. Could be some debris in a pipe or tap somewhere?
One tap will often affect another though - if one's on a short fat pipe and the other a long thin one, the latter will suffer. Downstairs hot pipes are usually 15mm, with 22mm to the bath though, so see what you can see...
In average pressure situations with an unvented HW cyl you wouldn't expect to notice a huge difference in tap behaviour upstairs and down. Could be some debris in a pipe or tap somewhere?
One tap will often affect another though - if one's on a short fat pipe and the other a long thin one, the latter will suffer. Downstairs hot pipes are usually 15mm, with 22mm to the bath though, so see what you can see...
Hi Guys
I've just had the Megaflo engineer around and found out the problem. Basically the system is unbalanced (as pointed out Fitz1). The plumber teed off before the cold water combination valve and is only balancing the hot water and not the cold main before the megaflo! That accounts for why there is a pressure loss when you flush the toilet. I can see why the plumber did this as there does not appear to be a stopcock (no one can find it) on the mains so he just took the easy way out. I now need to get him back to sort it out!
Also apparently the pressue will be 1/2 bar lower in the loft as you lose 1/2 bar per floor you go up. I'll have to switch to a smaller shower head to compensate.
Cheers.
I've just had the Megaflo engineer around and found out the problem. Basically the system is unbalanced (as pointed out Fitz1). The plumber teed off before the cold water combination valve and is only balancing the hot water and not the cold main before the megaflo! That accounts for why there is a pressure loss when you flush the toilet. I can see why the plumber did this as there does not appear to be a stopcock (no one can find it) on the mains so he just took the easy way out. I now need to get him back to sort it out!
Also apparently the pressue will be 1/2 bar lower in the loft as you lose 1/2 bar per floor you go up. I'll have to switch to a smaller shower head to compensate.
Cheers.
Dave - you mean the Megaflo engineer has suggested a cause of your problem. I wouldn't be so confident.
Unless you can tell us your mains pressure it's hard to comment further.
Half a bar per floor is rubbish, what other nonsense does he believe?
Regulating takes the pressure down not up. If the mains supply is strong enough to regulate (ie well over 3 bar), flushing a loo wouldn't normally affect the flow elsewhere noticeably. Sounds like you have pipe size issues - or blockages. Tap connector flexies with 6mm bores perhaps.
Unless you can tell us your mains pressure it's hard to comment further.
Half a bar per floor is rubbish, what other nonsense does he believe?
Regulating takes the pressure down not up. If the mains supply is strong enough to regulate (ie well over 3 bar), flushing a loo wouldn't normally affect the flow elsewhere noticeably. Sounds like you have pipe size issues - or blockages. Tap connector flexies with 6mm bores perhaps.
Ugh- this seems to be opening up a huge can of worms.
What is the easiest way to measure your mains pressure? Can I call Thames water and ask them? I asked my neighbour the other day and he seemed to think the pressure was around 2.7 bar.
The investigation continues....
What is the easiest way to measure your mains pressure? Can I call Thames water and ask them? I asked my neighbour the other day and he seemed to think the pressure was around 2.7 bar.
The investigation continues....
So after waiting in all day for the plumbers not to turn up I did my nut and they sent their trainee to look at the problem.
Apparently it's all down to my current pipework and there's not much I can do about that without ripping up half the floors in the house. The only thing that could be done was to put an isolator on the cold water tap in the kitchen so it does not cuase too much of a pressure decrease when it is used. Meanwhile if you use the washing machine it's back to the erratic pressure problem.
Now I have another problem that relates to the pressure release valve- it seems to be leaking off an on. I followed the instructions on the side to regenerate the air gap last night but I noticed that it was leaking when I returned this evening. I've asked the plumber to come back and check but he's saying it sounds as if there is a problem with the megaflow!!
Any advice? This is driving me insane!
Apparently it's all down to my current pipework and there's not much I can do about that without ripping up half the floors in the house. The only thing that could be done was to put an isolator on the cold water tap in the kitchen so it does not cuase too much of a pressure decrease when it is used. Meanwhile if you use the washing machine it's back to the erratic pressure problem.
Now I have another problem that relates to the pressure release valve- it seems to be leaking off an on. I followed the instructions on the side to regenerate the air gap last night but I noticed that it was leaking when I returned this evening. I've asked the plumber to come back and check but he's saying it sounds as if there is a problem with the megaflow!!
Any advice? This is driving me insane!
The plumber definitely is qualified to fit megaflows- I saw the ID and verified it.
The megaflow engineer also took a look at the system and said that it all looked to be OK other than not being balanced. He did mention that the pressue relief valve should be in a different position to where it is (possibly higher up). It looks as if I'll have to call Megaflow again.
Anyone know of any good plumbers in the South London area?
The megaflow engineer also took a look at the system and said that it all looked to be OK other than not being balanced. He did mention that the pressue relief valve should be in a different position to where it is (possibly higher up). It looks as if I'll have to call Megaflow again.
Anyone know of any good plumbers in the South London area?
A retarded wombat could tell you that if the mains pressure is 2.7 bar and the pressure reducing valve is set above that, it'll make absolutely no difference which side of the p.r. valve the cw is connected. A "balanced" output would be worse than a non balanced one, because of the inevitable resistance-pressure loss in the valve.
If your mains pressure were 7 bar andyou had a prv set to 3 bar, then yes, your hot and cold would both be 3 bar.
But. There is also a non-return valve in the "combination valve" and there is a bubble of air in the top of the Megaflo. That means that your megaflo charges up to the mains static pressure - after a while. Then when you call for water (HOT ONLY) you get it at full pressure , not reduced by pipework up to the megaflo. This makes your supplies UN balanced. Over time (minutes) the hot pressure will drop to what the mains alone can provide, via the input pipes. Hot and cold will then be the same apart from the pipe resistances.
The Bubble can be added to, and you can use a buggun for the cold water, before it goes into the Megaflo. The thing is a Pressure Vessel, with a few bits added, generally called an Accumulator. If you stooge around the net you'll find them.
If your mains pressure were 7 bar andyou had a prv set to 3 bar, then yes, your hot and cold would both be 3 bar.
But. There is also a non-return valve in the "combination valve" and there is a bubble of air in the top of the Megaflo. That means that your megaflo charges up to the mains static pressure - after a while. Then when you call for water (HOT ONLY) you get it at full pressure , not reduced by pipework up to the megaflo. This makes your supplies UN balanced. Over time (minutes) the hot pressure will drop to what the mains alone can provide, via the input pipes. Hot and cold will then be the same apart from the pipe resistances.
The Bubble can be added to, and you can use a buggun for the cold water, before it goes into the Megaflo. The thing is a Pressure Vessel, with a few bits added, generally called an Accumulator. If you stooge around the net you'll find them.
We can fix your Megaflo if the standing pressure is over 1.5 bar.
Providing it has been installed for over a year and you are in our installation area. See our accumulator page on the web site.
Simon
www.hwch.co.uk
Providing it has been installed for over a year and you are in our installation area. See our accumulator page on the web site.
Simon
www.hwch.co.uk
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