Megaflow cold feed.

[Dannypipe]

Yeah sorry. My bad. I think 22mm to cylinder will be fine. I'll shut up now!

 

[ferret]

I was saying 28mm cos usually you want balanced h+c ( well i do) from the cold water pack!!

 

[Gray0689]

I was saying 28mm cos usually you want balanced h+c ( well i do) from the cold water pack!!

What would a 28mm do for balanced hot and cold and what is a cold water pack
Ferret I guess you don't work on unvented

 

[ferret]

well like you said earlier , volume is required 2x 22mm feeds in my opinion will need 28mm , and a cold water pack where i come from is the valve ,prv,nrv and safety valve with the balanced cold tapping , do you work on unvented?? or do you just not do balanced systems??

 

[Gray0689]

well like you said earlier , volume is required 2x 22mm feeds in my opinion will need 28mm , and a cold water pack where i come from is the valve ,prv,nrv and safety valve with the balanced cold tapping , do you work on unvented?? or do you just not do balanced systems??

Well as I was talking about gas on the volume issue
Cold water pack? You mean combination valve

28mm will do nothing think you need to brush up mate read MI
And yes I work on unvented and yes I do ballance system right down to kitchen sink do you lol

 

[Plucky]

Well as I was talking about gas on the volume issue
Cold water pack? You mean combination valve

28mm will do nothing think you need to brush up mate read MI
And yes I work on unvented and yes I do ballance system right down to kitchen sink do you lol

Dont forget to leave one outlet on a non balanced supply, normally kitchen sink

Ecowarm, when he was reffering to an accumulator I think he was talking about a GAH or similar branded expansion tank deisgned to maitain water volume at time of high demand. Not a buffer type accumulator.

Something like this GAH - Introducing Coldstream

 

[Gray0689]

Why would you leave one outlet unbalanced that's why it's called a ballanced system your thinking of a mainsflow cylinder not the same

 

[ecowarm]

Dont forget to leave one outlet on a non balanced supply, normally kitchen sink

Ecowarm, when he was reffering to an accumulator I think he was talking about a GAH or similar branded expansion tank deisgned to maitain water volume at time of high demand. Not a buffer type accumulator.

Something like this GAH - Introducing Coldstream

Yes I know what he meant and a Megaflo does just that, not all unvented cylinders just the ones with an internal diaphragm as opposed to a separate expansion vessel.

Eco

Why would you leave one outlet unbalanced that's why it's called a ballanced system your thinking of a mainsflow cylinder not the same

Why would you need a balanced supply to a kitchen sink?

 

[Toddyplumb]

It does actually say in the Megaflow installation instructions that supplies to drinking water should be taken before the combination valve

 

[Gray0689]

I stand corected
I only use range or tempest or gledhill cylinders
Never used megaflow my suppliers dint stock them

 

[Dannypipe]

Gray, where do you order your gledhill parts? From your merchants or do you have a number? Only asking as I have to order some tomorrow and it's going to take me a while phoning around. Cheers in advance!

 

[Gray0689]

Dannypipe
I get cylinders and parts from Bassetts

 

[Dannypipe]

Oh right, just a local merchants. I'll try my guys in the morning then cheers. If not, I'll have to ask my wife to get on the phone. I get rubbish reception where I'm working tommorow!

I need a few bits for two different thermal stores. Rod stat without a thermal lockout and a few valves. My usual ebay source has closed his account. Very odd.

Cheers.

 

[ferret]

I stand corected
I only use range or tempest or gledhill cylinders
Never used megaflow my suppliers dint stock them

I,m sorry i thought the original thread was a mega flow , maybe with a tempest or gledhill a 4 bathroom house will run fine on 22mm when all taps and the w/machine dishwasher are in use. Now i,m no expert on the correct flow rates from taps etc but i can hazard an educated guess after working in the trade for 33years that 22mm will not do it correctly unless the whole house is run in microbore!!

 

[Gray0689]

I have done a 7 bed 7 ensuites
smart cylinder
22mm hot and cold feeds no problem at all

 

[ecowarm]

I have also done a very large farm house, 4 full bathrooms and two kitchens, 8 bedrooms and coped with parents 5 kids and several shooting parties.

The water main was upgraded to 32mm and then 28mm to dual 250l megaflo's then 28mm hot and cold balanced supplies, 22mm seconary return.

This is a very large house over three stories.

Normally 22mm is fine, doing a flat at the moment and its having 15mm supply to the unvented cylinder and balanced h/c and will be fine.

 

[ferret]

yeah fine if using taps with 8mm and 10mm connections , it aint fine with standard 22mm and 15mm connections , there would be too much pressure drop when taps etc are opened , I know that probably all taps etc won,t be open at the same time but system design should be based on the possibility that they are. ... pressure and volume = flow rate wether water or gas

 

[justlead1]

Hi. In support of Ferrets correct facts. I would like to add, when working with direct mains feed systems. i have found the fluctuation of mains pressure to be the fly in the ointment. And have witnessed it to change up to 5 fold from night to day (owing to peak demand) These condition will reduce the flow some 60 percent. Hence the need to up the supply pipe sizes where possible.

 

[ecowarm]

the flat mentioned above is owned by a one armed hermit with no friends so only 1 tap turned on

 

[Dannypipe]

In fairness, Ferret is right. I was called back to a bathroom suite I installed. The client complained that when she runs her bath the basin runs at a dribble.

The bath is 22mm, as it should be and basin 15mm. Both are taken from the 22mm that enters the bathrooom from an unvented cylinder.

I told her water will take it's easiest route. She said I was talking rubbish.

The supply to the unvented is 22mm with a brass pump and secondary flow loop. It's a bloody big house. Glad I didn't install the cylinder! Though in fairness they did a lovely job, perhaps they should have consulted this forum first!

Anyway, I'm off to work. Have a good day one and all!

 

[Gray0689]

That's nothing to do with whether it's 22 mm
That's the pressure in system I bet if you check the flow rate coming in on mains is to low if the pressure and flow rates where correct it would not happen

 

[Gray0689]

I think you mean it's got a seconderry return

 

[so-solar]

all this talk about a 28mm supply, what if the mains incomer is 25mm? just like a site i have just finished! the agent still insisted no a 28mm virgin main to the megaflo! you can run whatever size you like but if it is bigger than the incoming mdpe then it is a waste of money!

 

[Gray0689]

If the incoming mains is of the higher pressure and flow than needed the pressure reducing valve takes it down to the correct pressure
So if the correct checks are done before a cylinder is fitted 22mm is the correct way to do it

 

[so-solar]

so, if you do not get the required readings after doing your checks and you have an incoming 25mm main, you would automatically step up to 28mm?