Megaflo problem changing taps.

[djp123]

System is UNVENTED MEGAFLO


Previously I have changed bathroom and kitchen taps on two separate occasions. As far as I remember turning off the stop cock meant I could change the taps without draining.
Today trying to do the same now the hot water flows at normal pressure which would mean I have to empty the system.
Why would this, be can anyone advise please?

 

[kevplumb]

stop tap ain't working

 

[djp123]

Thank you but stop tap turns cold water off immediately.

 

[kevplumb]

Thank you but stop tap turns cold water off immediately.

This is an unvented MEGAFLO system

well i never!!! i wondered what the title meant

whichever stop tap your turning off is after the feed to the megaflo then

there should be an isolater near the cylinder

 

[djp123]

No the stop tap is the main one into house before the MEGAFLO what is strange is nothing has been altered and reading up turning the stop tap off should stop the flow from hot and cold taps which it always did.

This is a newish property and because of this system no isolating
switches on the piping leading to taps installed.

Will check again but I can see no Isolating Valve near the cylinder .

Oh dear!!

 

[kevplumb]

well it's getting a feed from somewhere

 

[tincup]

Hi

Have you let it run say for 20sec to clear the pipes?

 

[djp123]

Thank you for replying.


Yes let it run for a good 5 mns no change in flow.

 

[cozzmic]

On the pressure reducing set on the Megaflo there is a 1/4 turn black lever to isolate the supply to the cylinder also it will run for some time because the air gap built into the cylinder has to decompress therefore pushing out hot water for a wee while.

 

[Agile]

The cylinder has an air bubble at the top.

This will pressurise the cylinder even after the mains water is turned offf.

You will need to drain off about 1/2 of the tank volume so about 50-100 litres.

There should be a valve at the inlet to the pressure reducing valve so you can turn off just the cylinder without needing to have the cold water off.

Tony

 

[djp123]

Thank you everyone.

Having never had this problem before and only recently ( 2 months ago)regenerated the air gap maybe in the past do you think it was need of regeneration? Therefore could this be reason no problems last time?

 

[muggles]

Quite possibly